Backward Curved High Pressure Volume Fans - Twin City Fan ...

BACKWARD CURVED HIGH PRESSURE FANS
TYPE BCS
Defining Innovation.
BULLETIN 400-C
April 2001

High Efficiency Industrial Fans
The BCS fan from Twin City Fan & Blower is
a high efficiency backward curved industrial fan
designed for handling relatively clean air in high
pressure applications. Because the BCS features
a wider wheel and housing, producing a high
volume of air at a lower velocity, the need for
an expansion evasé is eliminated.
BCS fans are available with a variety of construction
options and accessories, offering the
versatility and flexibility required in today's industrial
applications.
Typical Applications
• Combustion air
• Product cooling
• Moisture blow-off
• Forced draft on fluid bed boilers
• Induced draft after baghouse process blowers
Capabilities
• Wheel diameters from 27" through 89"
• Capacities to 270,000 CFM
• Static pressures to 40" w.g.
• Airstream temperatures to 800°F
• Design 14, 17, 22 and 26 construction
• Arrangements 1, 3SI, 7SI, 8, 9 and 9F
• Belt and direct drive configurations
Arrangement
1 with unitary
base and belt
guard
600 BCS, 400 HP, Arr. 7SI with inlet box.
Installation in a steel mill.
©2001 Twin City Fan Companies, Ltd., Minneapolis, MN. All rights reserved.
Bulletin illustrations cover the general appearance of Twin City Fan & Blower products at the time of
publication and we reserve the right to make changes in design and construction at any time without notice.
Arrangement 9F
2 Twin City Bulletin 400

Construction Features
Wheel Construction
The BCS wheel features heavy-gauge steel construction
and a non-overloading wheel design,
suitable for applications requiring large
volumes of air at moderate to high
pressures.
The high efficiency wheel features
backward curved blades
of single thickness, continuously
welded to the rim and backplate.
A conical spun shroud (rim)
makes BCS fans less susceptible
to the performance losses associated
with poor inlet conditions.
All BCS wheels are statically and
dynamically balanced to grade G6.3 per
ANSI S2.19 for smooth operation prior to assembly
of the fan, followed by a final balance of the entire
rotating assembly.
Housing Construction
Heavy-gauge, reinforced, continuously welded housings
provide strength and durability for extended service
life — a necessity in all commercial and industrial
installations.
Outlet flanges for duct-connection as well as rigidity
are standard. Inlet collars for slip-joint connection
and lifting lugs are also standard. All housings are
reinforced with rigid bracing to increase structural
integrity. The support angles are intermittently welded
and caulked between welds to prevent bleed-through
corrosion. Precisely positioned cutoff plates and aerodynamically
spun inlet cones provide high efficiency
and smooth airflow through the fan.
Shaft
Shafts are AISI-1018, 1040 or 1045 hot-rolled steel
accurately turned, ground, polished, and ring gauged
for accuracy. Shafts are generously sized for first critical
speed of at least 1.43 times the maximum speed
for the class.
Arrangement 1
Bearings
Bearings are heavy-duty, grease-lubricated, anti-friction
ball or roller, self-aligning, pillow block type and are
selected for minimum average bearing life (AFBMA
L-50) in excess of 200,000 hours at the maximum
fan RPM.
Drive Configurations
Available in both direct and belt drive configurations.
Rotation and Discharge
Both clockwise and counterclockwise rotations are
available in various standard discharge positions. See
page 22.
Temperature Limits
Standard construction designed for temperatures up
to 300°F. Optional construction available to handle up
to 800°F. See page 7.
Outlet Flange
Punched outlet flange is provided as standard construction
on all sizes.
Construction
• Design 14 — for tip speeds up to 14,000 FPM
• Design 17 — for tip speeds up to 17,000 FPM
• Design 22 — for tip speeds up to 22,000 FPM
• Design 26 — for tip speeds up to 26,000 FPM
Mechanical Run Test & Final Vibration
Check
All fans are assembled for a mechanical run test as
well as final balance prior to shipment. Vibration readings
are taken on both fan bearings in the axial, horizontal,
and vertical directions at the specified speed.
Fans are balanced to 0.15 in/sec. peak or less.
3 Twin City Bulletin 400

Optional Construction
Spark Resistant Construction
Fan applications may involve the handling of potentially
explosive or flammable particles, fumes or vapors.
Such applications require careful consideration by the
system designer to insure the safe handling of such
gases. Twin City Fan & Blower offers the following
classifications of spark resistant construction per
AMCA Standard 99-0401-86. It is the specifier’s or the
user’s responsibility to specify the type of spark resistant
construction with full recognition of the potential
hazards and the degree of protection required.
Type A: All parts of the fan in contact with the air or
gas being handled shall be made of nonferrous
material — usually aluminum and limited
to 250°F.
Type B: The fan shall have a nonferrous wheel or
impeller and nonferrous ring about the opening
through which the shaft passes — usually
aluminum wheel and rub ring and limited to
250°F.
Type C: The fan shall be so constructed that a shift of
the wheel or impeller or shaft will not permit
two ferrous parts of the fan to rub or strike.
This is accomplished with an aluminum inlet
cone and rub ring. This construction is limited
to 500°F. Construction to 800°F is available
using a steel inlet cone with copper/bronze
lining.
Notes:
1. Bearings shall be placed outside the airstream.
Therefore, do not use Arrangement 3 or 7.
2. The user shall electrically ground all fan parts.
Refer to AMCA Standard 99-0401-86 for full details.
Inlet Boxes
Typical Detached Inlet Box Dimensions
C
A
To
Suit
Fan
D
B
F
High Temperature Construction
Airstream temperatures above 300°F require high
temperature construction. See page 7 for construction
requirements. Insulation pins and complete fan insulation
are available.
Split Housing
A flanged horizontal split housing is available on the
fan’s centerline. A pie-shaped split is also available for
wheel removal without disturbing the ductwork.
Fan with
Pie-Shaped
Split Housing
Special Materials
BCS fans can be constructed of special materials such
as aluminum and stainless steel.
SIZE A B
C
MAX.
D
MAX.
INLET
AREA
(SQ. FT.)
F
MAX.
270 14.75 44.50 3.19 16.69 4.56 2.50
300 16.50 49.50 4.19 18.19 5.67 2.50
330 18.25 54.50 4.25 19.75 6.91 2.50
365 20.00 60.25 4.25 21.75 8.37 2.50
402 22.25 63.50 5.25 23.75 10.28 2.50
445 24.50 73.50 6.25 25.75 12.51 2.50
490 27.00 81.00 6.25 28.25 15.19 2.50
542 30.00 89.50 6.25 31.25 18.65 2.50
600 33.00 99.00 6.25 34.25 22.69 2.50
660 36.50 109.00 6.25 37.25 27.63 2.50
730 40.00 120.50 6.25 40.75 33.47 2.50
807 44.50 134.00 6.25 44.75 41.41 2.50
890 49.00 147.00 6.25 49.25 50.02 2.50
Dimensions are not to be used for construction.
Dimensions are in inches unless otherwise noted.
4 Twin City Bulletin 400

Inlet Box Positions
270
Inlet Box
315
225
270°
225°
360
360°
315° 45°
135°
180°
180
Subbase
90°
45
135
90
Fan
Arr. 1 Fan With Detached Inlet Box
Can Be Supplied in Arr. 8
Inlet Box
Concrete
Fan
Arr. 3SI Fan With Integral Inlet Box, Centrally Supported
Wheel, Independent Bearing Pedestal To Be Installed
on Concrete Pedestals
NOTES:
1. Reference line is the top vertical axis through center of fan shaft.
2. Position of inlet box and air entry to inlet box is determined from
drive side of fan.
3. Position on inlet box is designated in degrees clockwise from top
vertical axis as shown.
4. Positions 135° to 225° in some cases interfere seriously with floor
structure.
Inlet Box
5 Twin City Bulletin 400
Inlet
Box
INLET BOX POSITION OF
POSITION NO. INLET BOXES
45 Angular Down Intake
90 Horizontal Right Intake
135 Angular Up Intake
180 Bottom Up Intake
225 Angular Up Intake
270 Horizontal Left Intake
315 Angular Down Intake
360 Top Down Intake
Fan
Steel Base
Fan
Arr. 1 Fan With Attached or Integral Inlet Box
Can Be Supplied in Arr. 8
Coupling
Motor
Arr. 7SI Fan Similar to Arr. 3SI Except Bearing Pedestal
& Motor Installed On Steel Common Base

Accessories
Inlet Box
An inlet box is designed to minimize pressure drop
and is recommended for applications where uniform
flow is difficult to obtain due to limited space. Inlet
boxes can be designed to be either detachable or
integral to the fan.
Inlet Box Damper
The inlet box damper pre-spins the air in the direction
of wheel rotation, resulting in a savings in horsepower
at reduced loads.
Variable Inlet Vanes
Variable inlet vanes are available to provide economical,
stable, and efficient air volume control for manual
or motorized operation. Nested inlet vanes are available
for Design 17 and are suitable for temperatures
to 300°F. External inlet vanes are available for Design
22 and 26 and are suitable for temperatures to 300°F.
Construction to 600°F is available for both.
External Inlet Vanes
Nested Inlet
Vanes
Outlet Dampers
Double surface airfoil blades are available in either
parallel or opposed blade design.
Fan Guards
Shaft, bearing, and belt guards are available in OSHA
type designs.
Drain
All fans are constructed with a weep hole in the bottom
of the housing. A threaded pipe coupling is welded
to the lowest point in the housing scroll to permit
wash water or condensation to drain from the fan.
Access Door
Bolted, quick-opening, and raised bolted access doors
are available for wheel inspection or maintenance.
Bolted
Access Door
Quick-Open
Access Door
Raised Bolted
Access Door
Shaft Seals
A variety of shaft seals are available to prevent contaminants
in the airstream from passing through the
shaft hole in the fan housing. The shaft seal is provided
as standard on all fans with applications over
300°F and fans with split housings. Although shaft
seals minimize air leakage, they are not a gas-tight
design.
Flanged Inlet
A punched inlet flange is available for duct mounting.
Temperature and Vibration Detectors
Thermocouples or RTDs are available to install on the
bearings. A variety of vibration switches are available.
Vibration Isolation Bases
Structural angle, structural channel, inertia bases, and
unitary bases are available with or without spring
isolators.
Screens
Safety screens are available for mounting in the fan
inlet or outlet in nonducted applications.
Special Coatings
Special coatings are available for corrosion protection.
6 Twin City Bulletin 400

Engineering Data
High Temperature Derating
Factors
AIRSTREAM WHEEL MATERIAL
TEMPERATURE STANDARD STEEL
(°F) DES. 17 DES. 14, 22, 26
70 1.00 1.00
200 0.99 0.97
250 0.98 0.96
300 0.98 0.95
350 0.97 0.94
400 0.96 0.93
450 0.94 0.92
500 0.93 0.92
550 0.92 0.91
600 0.90 0.90
650 0.89 0.89
700 0.88 0.87
750 0.87 0.86
800 0.84 0.84
Above 800 Consult Factory
When elevated temperatures are
encountered, maximum RPM allowable
must be derated according to
the above table. For stainless steel
derates, contact the factory.
High Temperature Construction Requirements
TEMP. TYPE
RANGE OF
(°F) BEARINGS
–22° to 300°
Ball or
Roller
301° to 500°
501° to 600°
601° to 800°
LUBRI-
CATION
Ball or High Temp
Roller Grease
Ball or High Temp
Roller Grease
Ball or High Temp
Roller Grease
Performance Correction For Temperature & Altitude
The performance tables in this catalog are based
on fans handling standard air at a density of 0.075
pounds per cubic foot. This is equivalent to air at
70°F at sea level (29.92 Hg barometric pressure). Thus,
when specified performance is at a density different
Temperature and Altitude Density Ratios
OTHER
REQUIREMENTS
AVAILABLE
ARRANGE-
MENTS
Grease Standard Fan 1, 8, 9, 9F
Shaft Cooler, Shaft Seal
Expansion & Non-Expansion 1, 8, 9, 9F
Bearings
Same as 301° to 500° With
Addition of High Temp 1, 8, 9, 9F
Aluminum Paint
Same as 501° to 600° With
Modification of 1, 8, 9F
Bearing Pedestal
The BCS product line is perfectly suited for high temperature airstream
applications. The above chart refers to fans of carbon steel construction.
When aluminum (spark resistant) or stainless steel construction is
required, additional fan modifications may be required. Contact factory
in these cases.
than standard, it must be converted to the equivalent
standard conditions before entering the performance
tables. The equivalent standard conditions can be calculated
by using the Temperature and Altitude Density
Ratios shown below.
AIR
TEMP.
(°F)
0
29.92
1000
28.86
2000
27.82
3000
26.82
ALTITUDE IN FEET ABOVE SEA LEVEL
4000 5000 6000 7000 8000
BAROMETRIC PRESSURE IN INCHES OF MERCURY
25.84 24.90 23.98 23.09 22.22
9000
21.39
10000
20.58
15000
16.89
20000
13.75
70 1.000 0.964 0.930 0.896 0.864 0.832 0.801 0.772 0.743 0.714 0.688 0.564 0.460
100 0.946 0.912 0.880 0.848 0.818 0.787 0.758 0.730 0.703 0.676 0.651 0.534 0.435
150 0.869 0.838 0.808 0.770 0.751 0.723 0.696 0.671 0.646 0.620 0.598 0.490 0.400
200 0.803 0.774 0.747 0.720 0.694 0.668 0.643 0.620 0.596 0.573 0.552 0.453 0.360
250 0.747 0.720 0.694 0.669 0.645 0.622 0.598 0.576 0.555 0.533 0.514 0.421 0.344
300 0.697 0.672 0.648 0.624 0.604 0.580 0.558 0.538 0.518 0.498 0.480 0.393 0.321
350 0.654 0.631 0.608 0.586 0.565 0.544 0.524 0.505 0.486 0.467 0.450 0.369 0.301
400 0.616 0.594 0.573 0.552 0.532 0.513 0.493 0.476 0.458 0.440 0.424 0.347 0.283
450 0.582 0.561 0.542 0.522 0.503 0.484 0.466 0.449 0.433 0.416 0.401 0.328 0.268
500 0.552 0.532 0.513 0.495 0.477 0.459 0.442 0.426 0.410 0.394 0.380 0.311 0.254
550 0.525 0.506 0.488 0.470 0.454 0.437 0.421 0.405 0.390 0.375 0.361 0.296 0.242
600 0.500 0.482 0.469 0.448 0.432 0.416 0.400 0.386 0.372 0.352 0.344 0.282 0.230
650 0.477 0.460 0.444 0.427 0.412 0.397 0.382 0.368 0.354 0.341 0.328 0.269 0.219
700 0.457 0.441 0.425 0.410 0.395 0.380 0.366 0.353 0.340 0.326 0.315 0.258 0.210
800 0.420 0.404 0.389 0.375 0.362 0.350 0.336 0.323 0.311 0.300 0.290 0.237 0.193
7 Twin City Bulletin 400

Engineering Data
Maximum RPM, Wheel Weights & WR 2
DESIGN 14 DESIGN 17 DESIGN 22 DESIGN 26
FAN SIZE MAX. WEIGHT WR2 MAX. WEIGHT WR2 MAX. WEIGHT WR2 MAX. WEIGHT WR2 RPM (LB) (LB-FT2 ) RPM (LB) (LB-FT2 ) RPM (LB) (LB-FT2 ) RPM (LB) (LB-FT2 )
270 — — — 2688 149 100 3112 162 112 3300 167 146
300 — — — 2419 161 129 2801 173 146 3300 194 170
330 — — — 2199 201 199 2546 207 214 3009 229 242
365 1467 224 291 1988 237 295 2302 294 391 2720 273 360
402 1329 265 427 1803 317 511 2088 349 595 2467 344 561
445 1202 412 781 1631 456 804 1888 492 898 2231 493 895
490 1092 481 1136 1481 613 1399 1780 686 1636 2027 702 1669
542 986 627 1792 1338 841 2387 1549 898 2642 1831 920 2673
600 892 746 2667 1082 949 3322 1401 983 3479 1655 1319 4859
660 810 1026 4053 984 1387 5704 1273 1309 5276 1504 1597 6829
730 735 1204 5980 890 1693 8759 1180 1548 7775 1360 2028 10773
807 663 1492 9358 804 2014 12992 1041 1992 12522 1230 2611 17107
890 602 1974 14185 730 2392 19054 944 2779 22036 1116 3835 30972
Shaft & Bearings Data
Bare Fan Weights (lb)
ARRANGEMENT 1, 9 & 9F ARRANGEMENT 8
SIZE DESIGN MAX. MIN FAN BCS MTR.
HP
SHAFT
SHEAVE
DIA.
DIA.*
BRGS RPM
MAX.
MTR.
HP
SHAFT
DIA.
BRGS
14 — — — — — — — —
270
17
22
75
100
8.5
7.4
2.188
2.438
RB-203
RB-207
1780
1780
50
50
2.188
2.188
HDB-203
HDB-203
26 125 CF 2.938 SRB-215 3500 150 2.438 SRB-207
14 — — — — — — — —
300
17
22
100
125
9.5
8.2
2.438
2.668
RB-207
RB-211
1780
1780
50
50
2.438
2.438
HDB-207
HDB-207
26 150 CF 2.938 SRB-215 1780 50 2.438 RB-207
14 — — — — — — — —
330
17
22
100
150
10.4
9.0
2.438
2.938
RB-207
RB-215
1780
1780
50
50
2.438
2.438
HDB-207
HDB-207
26 150 CF 2.938 SRB-215 1780 50 2.438 RB-207
14 50 9.1 2.438 HDB-207 1180 30 2.438 HDB-207
365
17
22
125
150
11.5
10.0
2.688
2.938
RB-211
SRB-215
1780
1780
100
100
2.938
2.938
HDB-215
HDB-215
26 250 CF 3.438 SRB-307 1780 100 2.938 RB-215
14 60 10.1 2.438 HDB-207 1180 50 2.438 HDB-207
402
17
22
150
200
12.7
13.1
2.938
3.438
RB-215
SRB-307
1780
1780
150
150
2.938
3.438
HDB-215
RB-307
26 350 9.3 3.938 SRB-315 1780 150 3.438 RB-307
14 75 11.2 2.688 RB-211 1180 75 2.688 HDB-211
445
17
22
200
300
14.1
11.0
3.438
3.938
RB-307
SRB-315
1180
1780
75
250
2.938
3.438
RB-215
RB-307
26 350 9.3 3.938 SRB-315 1780 250 3.438 RB-307
14 100 12.4 2.938 RB-215 880 75 2.938 HDB-215
490
17
22
250
350
15.5
12.9
3.938
3.938
RB-315
SRB-315
1180
1780
125
400
3.438
3.938
RB-307
RB-315
26 400 11.3 4.438 SRB-407 1780 400 3.938 RB-315
*MINIMUM FAN SHEAVE DIAMETER WHEN USING MAX. HP MOTOR.
CONSULT FACTORY ON APPLICATIONS OVER 250 HP.
CF = CONSULT FACTORY
ARRANGEMENT 1, 9 & 9F ARRANGEMENT 8
SIZE DESIGN MAX. MIN FAN BCS MTR.
HP
SHAFT
SHEAVE
DIA.
DIA.*
BRGS RPM
MAX.
MTR.
HP
SHAFT
DIA.
BRGS
14 125 13.9 3.438 RB-307 880 100 2.938 RB-215
542
17
22
300
400
17.1
14.8
3.938
4.438
RB-315
SRB-407
1180
1180
200
200
3.438
3.438
RB-307
RB-307
26 500 12.5 4.938 SRB-415 1780 600 4.438 SRB-407
14 125 15.7 3.438 RB-307 880 125 2.938 RB-215
600
17
22
250
500
19.8
16.4
3.938
4.938
RB-315
SRB-415
880
1180
125
300
3.438
3.938
RB-307
RB-315
26 500 13.8 4.938 SRB-415 1180 300 3.938 SRB-315
14 150 17.5 3.938 RB-315 700 125 3.438 RB-307
660
17
22
300
500
22.0
18.0
3.938
4.938
RB-315
SRB-415
880
1180
200
500
3.938
3.938
RB-315
RB-315
26 500 15.2 4.938 SRB-415 1180 500 4.938 SRB-415
14 200 19.7 3.938 RB-315 700 200 3.438 RB-307
730
17
22
350
500
25.6
19.4
4.438
4.938
SRB-407
SRB-415
880
1180
350
800
4.438
4.438
SRB-407
SRB-407
26 500 16.9 5.438 SRB-507 1180 800 4.938 SRB-415
14 250 22.1 4.438 SRB-407 590 200 3.938 SRB-315
807
17
22
450
500
26.4
22.0
4.938
4.938
SRB-415
SRB-415
700
880
300
700
4.438
4.438
SRB-407
SRB-407
26 500 18.6 5.438 SRB-507 1180 1300 5.438 SRB-507
14 300 24.7 4.938 SRB-415 590 300 4.438 SRB-407
890
17
22
500
500
29.9
24.3
4.938
4.938
SRB-415
SRB-415
700
880
450
1000
4.938
4.938
SRB-415
SRB-415
26 500 20.5 6.938 SRB-615 880 1000 5.438 SRB-507
BEARING CODES:
HDB = Heavy Duty Ball such as Dodge SCMAH, Dodge GTM or
Linkbelt PU300
RB = Roller Bearing such as Dodge S2000, SKF SYR Series or
Dodge IP Series
SRB = Split Roller Ball such as SKF SAF225 or Linkbelt PLB6800
Series
FAN DESIGN 14 DESIGN 17 DESIGN 22 DESIGN 26
SIZE ARR. 1 ARR. 8 ARR. 9 ARR. 9F ARR. 1 ARR. 8 ARR. 9 ARR. 9F ARR. 1 ARR. 8 ARR. 9 ARR. 9F ARR. 1 ARR. 8
270 — — — — 786 1022 826 865 1085 1411 1140 1194 1282 1667
300 — — — — 982 1277 1031 1080 1125 1463 1181 1238 1523 1980
330 — — — — 1190 1547 1249 1309 1520 1976 1596 1672 1943 2526
365 1090 1413 1144 1197 1430 1858 1501 1573 1889 2456 1983 2078 2340 3042
402 1406 1825 1476 1546 1810 2353 1901 1991 2386 3101 2505 2624 3035 3945
445 1660 2152 1742 1824 2219 2885 2330 2441 3122 4059 3278 3434 3720 4835
490 1940 2514 2035 2131 2811 3655 2952 3093 3730 4849 3917 4103 4569 5940
542 2847 3675 2985 3123 3708 4821 3894 4079 4752 6178 4990 5227 5635 7326
600 3341 4312 3503 3665 4460 5798 4683 4906 5676 7379 5960 6244 6765 8795
660 4255 5517 4466 4676 5538 7199 5815 6091 6864 8923 7207 7551 7930 10308
730 5195 6735 5452 5709 7001 9101 7351 7701 8099 10528 8504 8908 9603 12484
807 5264 6835 5526 — 8739 11361 9176 9613 10134 13174 10641 11147 11878 15441
890 7262 9421 7622 — 10334 13434 10851 11367 12366 16075 12984 13602 15110 19643
8 Twin City Bulletin 400

Performance Data
Max. RPM
Design 14 Design 17 Design 22 Design 26
NA 2687 3112 3678
270 BCS Outlet Area: 4.19 ft 2 Wheel Diameter.: 27" Tip Speed (FPM): 7.07 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
5028 1200 679 1.03 861 2.01 1024 3.13
5447 1300 704 1.15 877 2.17 1032 3.33
5866 1400 731 1.28 895 2.34 1044 3.54 1182 4.85
6285 1500 760 1.43 915 2.52 1058 3.76 1191 5.11 1317 6.57
6704 1600 789 1.58 937 2.72 1075 4.01 1203 5.40 1324 6.89
7123 1700 820 1.76 961 2.93 1093 4.27 1217 5.70 1333 7.21 1446 8.85
7542 1800 851 1.95 986 3.16 1113 4.54 1233 6.02 1345 7.57 1454 9.24 1559 10.99
7961 1900 883 2.16 1012 3.41 1134 4.82 1250 6.35 1360 7.96 1464 9.63 1566 11.43 1664 13.28
8380 2000 916 2.38 1039 3.68 1156 5.11 1269 6.70 1375 8.35 1477 10.08 1575 11.89 1671 13.79 1763 15.74
9218 2200 983 2.89 1096 4.27 1205 5.78 1310 7.43 1411 9.19 1507 11.01 1600 12.89 1690 14.86 1778 16.90
10056 2400 1052 3.48 1157 4.95 1258 6.54 1356 8.26 1451 10.09 1543 12.02 1631 14.00 1716 16.02 1800 18.15
10894 2600 1122 4.14 1220 5.72 1314 7.39 1406 9.18 1495 11.07 1582 13.08 1667 15.18 1748 17.30 1828 19.50
11732 2800 1193 4.90 1285 6.60 1373 8.35 1459 10.21 1544 12.19 1626 14.25 1706 16.41 1785 18.67 1861 20.96
12570 3000 1265 5.76 1352 7.58 1435 9.42 1516 11.37 1595 13.39 1673 15.53 1749 17.75 1824 20.08 1898 22.50
13408 3200 1337 6.71 1420 8.66 1498 10.60 1575 12.63 1650 14.74 1724 16.95 1796 19.23 1867 21.61 1938 24.12
14246 3400 1410 7.79 1489 9.86 1563 11.90 1635 13.99 1707 16.21 1777 18.49 1846 20.84 1914 23.30 1981 25.84
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
10056 2400 1881 20.32 1961 22.57 2039 24.88 2116 27.27
10894 2600 1905 21.73 1981 24.05 2056 26.45 2129 28.88 2201 31.37
11732 2800 1935 23.28 2008 25.68 2079 28.12 2149 30.63 2217 33.16 2352 38.47
12570 3000 1969 24.92 2039 27.41 2107 29.92 2174 32.49 2240 35.12 2369 40.55 2495 46.20 2617 52.00
13408 3200 2006 26.63 2074 29.24 2139 31.83 2204 34.50 2267 37.18 2391 42.73 2512 48.52 2630 54.48 2746 60.66
14246 3400 2047 28.46 2112 31.15 2175 33.85 2238 36.64 2299 39.42 2418 45.10 2535 51.03 2648 57.10 2760 63.42
15084 3600 2090 30.37 2153 33.16 2214 35.96 2274 38.81 2334 41.75 2449 47.61 2562 53.69 2671 59.87 2778 66.26
15922 3800 2137 32.48 2196 35.27 2255 38.16 2314 41.15 2371 44.13 2483 50.23 2592 56.46 2698 62.82 2802 69.37
16760 4000 2186 34.73 2243 37.59 2300 40.56 2356 43.58 2411 46.64 2520 52.96 2626 59.42 2728 65.90 2829 72.61
17598 4200 2237 37.13 2292 40.06 2346 43.05 2400 46.13 2454 49.31 2559 55.77 2662 62.43 2762 69.18 2859 75.99
18436 4400 2291 39.75 2343 42.70 2396 45.80 2448 48.95 2499 52.13 2601 58.76 2700 65.53 2798 72.54 2893 79.60
19274 4600 2346 42.51 2397 45.58 2447 48.69 2497 51.88 2547 55.17 2644 61.83 2741 68.83 2835 75.92 2928 83.22
20112 4800 2403 45.46 2452 48.60 2500 51.77 2548 55.01 2596 58.34 2691 65.20 2784 72.27 2875 79.50 2966 87.02
20950 5000 2461 48.56 2508 51.77 2555 55.06 2602 58.42 2648 61.79 2739 68.71 2829 75.89 2918 83.32 3005 90.88
21788 5200 2521 51.88 2566 55.16 2611 58.50 2656 61.91 2701 65.39 2789 72.43 2876 79.72 2962 87.25 3047 94.99
22626 5400 2581 55.33 2625 58.72 2669 62.18 2713 65.71 2756 69.23 2841 76.40 2925 83.78 3008 91.39 3091 99.30
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
14246 3400 2869 69.86 2976 76.50
15084 3600 2884 72.90 2988 79.68 3089 86.54
15922 3800 2903 76.02 3004 82.99 3102 89.99 3199 97.18 3294 104.50
16760 4000 2927 79.40 3024 86.42 3119 93.57 3213 100.90 3306 108.40 3397 115.99 3487 123.77
17598 4200 2955 83.00 3049 90.14 3141 97.39 3232 104.86 3322 112.48 3410 120.15 3498 128.08 3584 136.06 3668 144.10
18436 4400 2985 86.68 3077 94.03 3166 101.38 3254 108.91 3341 116.63 3427 124.51 3512 132.51 3596 140.64
19274 4600 3019 90.62 3107 98.00 3194 105.55 3280 113.25 3365 121.13 3448 129.06 3530 137.15 3612 145.46
20112 4800 3054 94.56 3140 102.17 3225 109.91 3309 117.81 3391 125.73 3472 133.81 3552 142.02 3631 150.37
20950 5000 3091 98.62 3176 106.54 3259 114.50 3340 122.47 3420 130.57 3499 138.79 3577 147.13 3654 155.59
21788 5200 3131 102.93 3213 110.94 3294 119.09 3373 127.25 3452 135.64 3529 144.01 3605 152.49
22626 5400 3172 107.32 3252 115.50 3331 123.83 3409 132.28 3485 140.72 3561 149.38 3635 158.00
23464 5600 3215 111.91 3293 120.25 3370 128.74 3446 137.35 3521 146.08 3594 154.77 3667 163.66
24302 5800 3260 116.75 3336 125.23 3411 133.86 3485 142.61 3558 151.48 3630 160.44
25140 6000 3307 121.85 3380 130.34 3453 139.10 3525 147.98 3597 157.09 3667 166.18
25978 6200 3355 127.13 3427 135.85 3498 144.72 3568 153.71 3637 162.81
26816 6400 3405 132.74 3475 141.56 3543 150.39 3612 159.61
Underlined numbers indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
9 Twin City Bulletin 400

Performance Data
Max. RPM
300 BCS Outlet Area: 5.17 ft 2 Wheel Diameter.: 30" Tip Speed (FPM): 7.85 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
6204 1200 611 1.28 775 2.49 921 3.86
6721 1300 634 1.42 789 2.68 929 4.11
7238 1400 658 1.58 806 2.90 940 4.37 1064 5.99
7755 1500 683 1.76 824 3.12 953 4.66 1072 6.31 1185 8.10
8272 1600 710 1.95 843 3.35 967 4.95 1082 6.65 1192 8.51
8789 1700 737 2.16 864 3.61 984 5.27 1095 7.03 1200 8.91 1301 10.91
9306 1800 766 2.41 887 3.90 1001 5.59 1109 7.42 1211 9.35 1308 11.38 1403 13.56
9823 1900 795 2.66 910 4.20 1020 5.93 1125 7.84 1223 9.80 1318 11.90 1409 14.09 1498 16.41
10340 2000 824 2.94 935 4.54 1041 6.32 1142 8.27 1238 10.31 1329 12.43 1417 14.65 1504 17.03 1587 19.44
11374 2200 885 3.57 986 5.26 1084 7.13 1179 9.17 1269 11.33 1356 13.58 1440 15.92 1521 18.34 1600 20.86
12408 2400 947 4.29 1041 6.11 1132 8.07 1220 10.18 1305 12.43 1388 14.82 1468 17.28 1545 19.80 1620 22.40
13442 2600 1009 5.10 1098 7.07 1182 9.11 1265 11.32 1345 13.65 1424 16.16 1500 18.73 1573 21.34 1645 24.06
14476 2800 1073 6.04 1156 8.13 1236 10.31 1313 12.60 1389 15.03 1463 17.58 1535 20.25 1606 23.03 1675 25.88
15510 3000 1138 7.10 1216 9.34 1291 11.62 1364 14.02 1435 16.51 1505 19.14 1574 21.91 1642 24.81 1708 27.77
16544 3200 1203 8.28 1277 10.67 1348 13.08 1417 15.58 1484 18.17 1551 20.90 1616 23.72 1680 26.66 1743 29.71
17578 3400 1268 9.59 1339 12.15 1406 14.67 1471 17.26 1536 20.01 1599 22.81 1661 25.72 1722 28.73 1782 31.85
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
12408 2400 1693 25.08 1765 27.87 1835 30.70 1904 33.63
13442 2600 1715 26.84 1783 29.68 1850 32.62 1916 35.64 1981 38.73
14476 2800 1741 28.72 1807 31.69 1871 34.70 1934 37.80 1995 40.91 2117 47.49
15510 3000 1772 30.76 1835 33.83 1896 36.91 1956 40.07 2016 43.35 2132 50.04 2245 56.98 2356 64.24
16544 3200 1805 32.85 1866 36.06 1925 39.28 1983 42.55 2040 45.88 2152 52.76 2261 59.91 2367 67.24 2471 74.83
17578 3400 1842 35.12 1900 38.40 1957 41.75 2014 45.22 2069 48.66 2176 55.65 2281 62.95 2383 70.46 2484 78.28
18612 3600 1881 37.50 1937 40.90 1992 44.36 2047 47.94 2100 51.50 2204 58.76 2305 66.21 2404 73.91 2500 81.77
19646 3800 1923 40.08 1976 43.51 2029 47.07 2082 50.76 2134 54.48 2235 62.03 2333 69.71 2428 77.53 2521 85.54
20680 4000 1967 42.85 2018 46.36 2069 50.00 2120 53.77 2170 57.58 2268 65.38 2363 73.31 2455 81.32 2546 89.61
21714 4200 2013 45.82 2062 49.40 2111 53.11 2160 56.95 2208 60.83 2303 68.84 2395 76.99 2485 85.32 2573 93.79
22748 4400 2061 49.02 2108 52.67 2156 56.52 2202 60.33 2249 64.35 2340 72.46 2430 80.90 2517 89.42 2603 98.18
23782 4600 2111 52.45 2156 56.18 2202 60.09 2247 64.03 2291 68.00 2379 76.27 2466 84.88 2551 93.66 2635 102.71
24816 4800 2162 56.07 2206 59.94 2250 63.92 2293 67.90 2336 71.99 2421 80.41 2505 89.16 2587 98.09 2669 107.38
25850 5000 2214 59.88 2257 63.90 2299 67.93 2341 72.05 2382 76.17 2464 84.71 2545 93.57 2625 102.72 2704 112.13
26884 5200 2268 63.98 2309 68.07 2349 72.15 2390 76.40 2430 80.64 2510 89.42 2588 98.37 2665 107.62 2742 117.23
27918 5400 2322 68.23 2362 72.46 2401 76.67 2441 81.06 2479 85.33 2556 94.22 2632 103.37 2707 112.80 2781 122.48
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
17578 3400 2582 86.21 2678 94.38
18612 3600 2595 89.91 2689 98.32 2780 106.80
19646 3800 2613 93.87 2703 102.37 2792 111.09 2879 119.93 2965 129.03
20680 4000 2634 97.97 2721 106.59 2807 115.48 2892 124.57 2975 133.73 3057 143.11 3138 152.72
21714 4200 2659 102.39 2744 111.25 2827 120.23 2908 129.32 2989 138.72 3069 148.29 3148 158.05 3225 167.84 3301 177.82
22748 4400 2687 107.06 2769 116.02 2849 125.08 2929 134.48 3007 143.97 3084 153.63 3161 163.59 3236 173.52
23782 4600 2716 111.73 2796 120.93 2875 130.34 2952 139.79 3028 149.44 3103 159.27 3177 169.28 3250 179.40
24816 4800 2748 116.66 2826 126.12 2902 135.61 2978 145.40 3052 155.22 3124 165.03 3197 175.33 3268 185.62
25850 5000 2782 121.76 2858 131.46 2932 141.18 3006 151.18 3078 161.17 3149 171.29 3219 181.55 3288 191.94
26884 5200 2817 126.95 2891 136.85 2964 146.92 3036 157.13 3106 167.30 3175 177.58 3244 188.14
27918 5400 2854 132.38 2926 142.47 2997 152.72 3067 163.12 3136 173.63 3204 184.24 3271 194.95
28952 5600 2893 138.09 2963 148.35 3032 158.77 3101 169.49 3168 180.17 3235 191.12 3300 201.97
29986 5800 2933 143.99 3002 154.54 3069 165.10 3136 175.98 3202 186.97 3267 198.06
31020 6000 2976 150.38 3042 160.92 3107 171.60 3172 182.59 3237 193.88 3300 205.09
32054 6200 3019 156.88 3083 167.51 3147 178.46 3210 189.56 3273 200.94
33088 6400 3064 163.80 3127 174.68 3188 185.55 3250 196.90
Underlined numbers indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
Design 14 Design 17 Design 22 Design 26
NA 2420 2801 3310
10 Twin City Bulletin 400

Performance Data
Max. RPM
330 BCS Outlet Area: 6.26 ft 2 Wheel Diameter.: 33" Tip Speed (FPM): 8.64 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
7512 1200 556 1.55 704 3.00 837 4.67
8138 1300 576 1.72 718 3.25 844 4.96
8764 1400 598 1.91 733 3.51 854 5.28 967 7.24
9390 1500 622 2.14 749 3.77 866 5.63 975 7.65 1078 9.83
10016 1600 646 2.37 767 4.07 880 6.00 984 8.06 1083 10.28
10642 1700 671 2.63 786 4.38 894 6.37 996 8.52 1091 10.79 1183 13.21
11268 1800 696 2.91 806 4.71 911 6.78 1008 8.98 1101 11.32 1190 13.81 1275 16.39
11894 1900 723 3.23 828 5.09 928 7.20 1023 9.49 1112 11.87 1198 14.40 1281 17.06 1362 19.87
12520 2000 750 3.57 850 5.49 946 7.64 1038 10.00 1125 12.47 1208 15.04 1289 17.77 1367 20.60 1443 23.55
13772 2200 805 4.33 897 6.38 986 8.64 1072 11.11 1154 13.72 1233 16.44 1309 19.26 1383 22.21 1455 25.27
15024 2400 861 5.20 947 7.40 1029 9.76 1109 12.32 1187 15.07 1262 17.94 1335 20.94 1404 23.93 1472 27.07
16276 2600 918 6.19 998 8.55 1075 11.04 1150 13.70 1223 16.53 1295 19.57 1364 22.68 1431 25.88 1496 29.15
17528 2800 976 7.32 1052 9.87 1124 12.49 1194 15.26 1263 18.19 1330 21.28 1396 24.53 1460 27.87 1523 31.33
18780 3000 1035 8.61 1106 11.32 1174 14.07 1240 16.96 1305 20.00 1369 23.20 1431 26.52 1493 30.04 1553 33.62
20032 3200 1094 10.03 1162 12.95 1226 15.84 1288 18.84 1350 22.03 1410 25.29 1470 28.76 1528 32.31 1585 35.98
21284 3400 1154 11.64 1218 14.72 1279 17.79 1338 20.92 1397 24.24 1454 27.62 1510 31.12 1566 34.80 1621 38.61
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
15024 2400 1539 30.35 1604 33.69 1668 37.14 1731 40.71
16276 2600 1559 32.48 1621 35.93 1682 39.50 1742 43.15 1801 46.88
17528 2800 1583 34.77 1643 38.37 1701 42.01 1758 45.74 1814 49.55 1925 57.52
18780 3000 1611 37.23 1668 40.93 1724 44.70 1779 48.56 1833 52.49 1938 60.55 2041 68.98 2142 77.77
20032 3200 1642 39.83 1697 43.69 1751 47.62 1803 51.52 1855 55.56 1957 63.91 2055 72.46 2152 81.41 2247 90.66
21284 3400 1675 42.53 1728 46.53 1780 50.60 1831 54.73 1881 58.89 1979 67.44 2074 76.23 2167 85.35 2258 94.72
22536 3600 1710 45.37 1761 49.49 1811 53.68 1861 58.02 1909 62.31 2004 71.16 2096 80.19 2185 89.39 2273 99.00
23788 3800 1748 48.49 1797 52.71 1845 57.00 1893 61.44 1940 65.93 2032 75.08 2121 84.38 2208 93.92 2292 103.56
25040 4000 1788 51.83 1835 56.14 1882 60.61 1928 65.14 1973 69.71 2062 79.13 2148 88.69 2232 98.44 2315 108.52
26292 4200 1830 55.44 1875 59.82 1920 64.36 1964 68.95 2008 73.69 2094 83.35 2178 93.26 2260 103.38 2340 113.64
27544 4400 1874 59.34 1917 63.79 1960 68.39 2003 73.13 2045 77.91 2128 87.77 2209 97.88 2289 108.33 2367 118.92
28796 4600 1919 63.45 1961 68.08 2002 72.72 2043 77.50 2084 82.43 2164 92.45 2243 102.87 2320 113.48 2396 124.37
30048 4800 1966 67.89 2006 72.59 2046 77.39 2085 82.21 2124 87.15 2202 97.44 2278 107.99 2353 118.87 2426 129.89
31300 5000 2014 72.59 2052 77.34 2091 82.31 2129 87.28 2166 92.23 2241 102.64 2315 113.42 2387 124.40 2459 135.82
32552 5200 2062 77.43 2100 82.46 2137 87.48 2173 92.47 2210 97.69 2282 108.21 2353 119.07 2424 130.42 2493 141.90
33804 5400 2112 82.68 2148 87.75 2184 92.92 2220 98.19 2255 103.43 2325 114.21 2393 125.12 2461 136.50 2529 148.34
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
21284 3400 2347 104.32 2435 114.30
22536 3600 2360 108.95 2444 118.93 2528 129.38
23788 3800 2376 113.69 2457 123.86 2538 134.43 2618 145.29 2695 156.10
25040 4000 2395 118.64 2474 129.07 2552 139.80 2629 150.76 2705 161.96 2780 173.40 2853 184.90
26292 4200 2418 124.03 2494 134.55 2570 145.51 2644 156.58 2718 168.04 2790 179.50 2862 191.34 2932 203.20 3001 215.26
27544 4400 2443 129.60 2517 140.37 2590 151.38 2663 162.82 2734 174.32 2804 186.02 2874 198.07 2942 210.07
28796 4600 2470 135.36 2542 146.39 2614 157.81 2684 169.26 2753 180.92 2821 192.78 2888 204.84 2955 217.24
30048 4800 2499 141.31 2570 152.79 2639 164.26 2707 175.92 2774 187.74 2841 199.95 2906 212.12 2971 224.68
31300 5000 2529 147.33 2598 159.05 2666 170.95 2733 183.01 2798 195.01 2863 207.37 2927 219.87 2990 232.52
32552 5200 2562 153.81 2629 165.76 2695 177.89 2760 190.16 2824 202.55 2887 215.06 2949 227.68
33804 5400 2595 160.26 2661 172.59 2726 185.10 2789 197.57 2852 210.37 2913 223.03 2974 236.02
35056 5600 2631 167.28 2694 179.58 2757 192.26 2820 205.30 2881 218.26 2941 231.31 3000 244.42
36308 5800 2667 174.35 2729 186.98 2791 200.00 2851 212.96 2911 226.27 2970 239.68
37560 6000 2706 182.07 2766 194.82 2826 207.97 2885 221.26 2943 234.67 3001 248.42
38812 6200 2746 190.12 2804 202.96 2862 216.19 2919 229.56 2976 243.28
40064 6400 2786 198.30 2843 211.42 2899 224.70 2955 238.36
Underlined numbers indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
Design 14 Design 17 Design 22 Design 26
NA 2199 2546 3009
11 Twin City Bulletin 400

Performance Data
Max. RPM
365 BCS Outlet Area: 7.66 ft 2 Wheel Diameter.: 36.5" Tip Speed (FPM): 9.56 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
9192 1200 503 1.90 637 3.68 757 5.72
9958 1300 521 2.10 649 3.98 764 6.09
10724 1400 541 2.34 662 4.28 772 6.46 875 8.88
11490 1500 562 2.61 677 4.61 783 6.89 881 9.34 974 12.00
12256 1600 584 2.90 693 4.96 795 7.33 890 9.87 979 12.57
13022 1700 606 3.21 711 5.36 809 7.81 900 10.41 986 13.18 1070 16.19
13788 1800 630 3.57 729 5.77 823 8.28 912 11.00 995 13.83 1076 16.90 1153 20.07
14554 1900 654 3.95 749 6.24 839 8.81 925 11.62 1006 14.55 1083 17.61 1158 20.87 1231 24.28
15320 2000 678 4.36 769 6.73 856 9.37 939 12.25 1017 15.25 1093 18.44 1165 21.72 1236 25.21 1304 28.77
16852 2200 728 5.30 811 7.80 892 10.58 969 13.58 1044 16.81 1115 20.13 1184 23.59 1250 27.14 1315 30.88
18384 2400 779 6.37 856 9.05 931 11.97 1003 15.08 1073 18.43 1141 21.95 1207 25.61 1270 29.32 1331 33.13
19916 2600 830 7.57 903 10.48 972 13.51 1040 16.77 1106 20.24 1171 23.95 1233 27.74 1294 31.68 1352 35.62
21448 2800 883 8.97 951 12.07 1016 15.27 1080 18.69 1142 22.26 1203 26.06 1262 30.00 1320 34.10 1377 38.34
22980 3000 936 10.54 1000 13.84 1062 17.24 1122 20.80 1180 24.48 1238 28.40 1294 32.46 1350 36.76 1404 41.12
24512 3200 989 12.27 1051 15.86 1109 19.41 1165 23.08 1221 26.98 1275 30.95 1329 35.18 1382 39.57 1433 44.02
26044 3400 1043 14.23 1102 18.05 1157 21.80 1210 25.61 1263 29.65 1315 33.82 1366 38.13 1416 42.59 1465 47.18
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
18384 2400 1391 37.10 1451 41.29 1508 45.44 1565 49.81
19916 2600 1409 39.70 1466 44.00 1521 48.35 1575 52.79 1628 57.33
21448 2800 1432 42.61 1485 46.91 1538 51.41 1589 55.91 1640 60.62 1740 70.33
22980 3000 1457 45.60 1508 50.07 1559 54.73 1608 59.36 1657 64.19 1752 74.07 1846 84.49 1936 95.07
24512 3200 1484 48.67 1534 53.42 1583 58.25 1630 63.02 1677 67.96 1769 78.15 1858 88.66 1946 99.66 2031 110.83
26044 3400 1514 51.99 1562 56.89 1609 61.87 1655 66.90 1701 72.10 1789 82.48 1875 93.24 1959 104.39 2041 115.81
27576 3600 1546 55.50 1593 60.65 1638 65.76 1683 71.04 1726 76.24 1812 87.08 1895 98.11 1976 109.46 2055 121.12
29108 3800 1581 59.38 1625 64.52 1669 69.85 1712 75.24 1754 80.66 1837 91.84 1918 103.30 1996 114.86 2073 126.84
30640 4000 1617 63.46 1659 68.67 1701 74.08 1743 79.67 1784 85.31 1864 96.77 1942 108.50 2018 120.44 2093 132.77
32172 4200 1655 67.88 1696 73.29 1736 78.75 1776 84.40 1815 90.08 1893 101.93 1969 114.07 2043 126.42 2115 138.91
33704 4400 1695 72.68 1734 78.15 1772 83.65 1811 89.47 1849 95.33 1924 107.39 1998 119.90 2070 132.63 2140 145.48
35236 4600 1736 77.76 1773 83.29 1810 88.96 1847 94.80 1884 100.81 1956 113.02 2028 125.86 2098 138.92 2166 152.11
36768 4800 1778 83.13 1814 88.85 1850 94.71 1885 100.56 1921 106.73 1991 119.23 2060 132.19 2127 145.35 2194 159.04
38300 5000 1821 88.81 1856 94.73 1890 100.61 1925 106.79 1959 112.95 2026 125.54 2093 138.76 2159 152.38 2223 166.11
39832 5200 1865 94.83 1899 100.94 1932 107.00 1965 113.19 1998 119.50 2064 132.54 2128 145.80 2191 159.43 2254 173.61
41364 5400 1910 101.23 1942 107.34 1975 113.75 2007 120.10 2039 126.57 2102 139.70 2164 153.17 2226 167.21 2286 181.36
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
26044 3400 2122 127.65 2201 139.75
27576 3600 2133 133.17 2210 145.58 2285 158.18
29108 3800 2148 139.06 2222 151.66 2295 164.56 2367 177.77 2437 191.10
30640 4000 2166 145.28 2237 157.96 2308 171.20 2377 184.48 2446 198.24 2513 212.04 2579 226.12
32172 4200 2186 151.72 2255 164.65 2324 178.13 2391 191.70 2457 205.50 2523 219.75 2587 233.96 2651 248.66 2714 263.60
33704 4400 2209 158.62 2276 171.82 2342 185.30 2407 199.04 2472 213.32 2535 227.57 2598 242.23 2660 257.06
35236 4600 2233 165.57 2299 179.27 2363 192.98 2427 207.18 2489 221.34 2551 236.01 2611 250.60 2672 265.90
36768 4800 2259 172.80 2323 186.79 2386 200.98 2448 215.38 2509 229.97 2569 244.75 2628 259.72 2686 274.85
38300 5000 2287 180.36 2349 194.62 2411 209.32 2471 223.92 2530 238.67 2589 253.86 2646 268.90 2703 284.39
39832 5200 2316 188.09 2377 202.81 2437 217.74 2496 232.82 2554 248.04 2611 263.37 2667 278.80
41364 5400 2347 196.27 2406 211.19 2464 226.30 2522 241.84 2578 257.21 2634 272.97 2689 288.81
42896 5600 2379 204.73 2436 219.79 2493 235.31 2549 250.99 2605 267.10 2659 282.99 2713 299.25
44428 5800 2412 213.49 2468 228.93 2523 244.57 2578 260.65 2632 276.86 2686 293.48
45960 6000 2447 222.87 2501 238.41 2555 254.42 2608 270.58 2661 287.16 2713 303.85
47492 6200 2483 232.67 2535 248.26 2588 264.62 2640 281.13 2691 297.75
49024 6400 2519 242.64 2571 258.83 2622 275.21 2672 291.73
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
Design 14 Design 17 Design 22 Design 26
1467 1987 2302 2720
12 Twin City Bulletin 400

Performance Data
Max. RPM
402 BCS Outlet Area: 9.31 ft 2 Wheel Diameter.: 40.25" Tip Speed (FPM): 10.54 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
11172 1200 456 2.31 577 4.46 687 6.97
12103 1300 472 2.55 588 4.83 692 7.38
13034 1400 491 2.86 601 5.22 700 7.85 793 10.77
13965 1500 509 3.16 614 5.61 710 8.37 799 11.36 884 14.62
14896 1600 529 3.51 629 6.05 721 8.91 807 12.00 888 15.29
15827 1700 550 3.91 644 6.50 733 9.47 816 12.65 894 16.02 970 19.66
16758 1800 571 4.33 661 7.02 746 10.05 827 13.38 903 16.86 975 20.50 1046 24.43
17689 1900 592 4.78 679 7.58 761 10.72 838 14.08 912 17.67 982 21.41 1050 25.36 1116 29.50
18620 2000 615 5.31 697 8.17 776 11.38 851 14.87 922 18.52 991 22.41 1057 26.45 1121 30.66 1183 35.02
20482 2200 660 6.44 735 9.47 808 12.83 879 16.53 946 20.40 1011 24.47 1073 28.63 1134 33.04 1193 37.59
22344 2400 706 7.73 776 11.00 844 14.54 909 18.31 973 22.41 1035 26.72 1094 31.10 1151 35.59 1207 40.28
24206 2600 753 9.22 818 12.70 882 16.46 943 20.39 1003 24.62 1061 29.05 1118 33.72 1173 38.48 1226 43.31
26068 2800 800 10.88 862 14.66 921 18.55 979 22.70 1035 27.03 1091 31.70 1144 36.44 1197 41.46 1248 46.53
27930 3000 848 12.78 907 16.85 962 20.90 1017 25.26 1070 29.76 1122 34.48 1173 39.43 1224 44.67 1273 49.98
29792 3200 897 14.93 952 19.22 1005 23.56 1056 28.03 1107 32.78 1156 37.62 1205 42.76 1253 48.09 1300 53.59
31654 3400 946 17.31 999 21.93 1049 26.49 1097 31.12 1145 36.03 1192 41.08 1238 46.29 1284 51.78 1329 57.44
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
22344 2400 1262 45.17 1315 50.11 1368 55.30 1419 60.53
24206 2600 1278 48.30 1329 53.45 1379 58.75 1428 64.15 1476 69.65
26068 2800 1298 51.74 1347 57.07 1394 62.40 1441 67.98 1487 73.66 1578 85.52
27930 3000 1321 55.41 1368 60.94 1413 66.43 1458 72.15 1502 77.95 1589 90.09 1674 102.72 1756 115.65
29792 3200 1346 59.22 1391 64.95 1435 70.74 1478 76.60 1521 82.67 1604 94.98 1685 107.81 1764 121.01 1842 134.79
31654 3400 1373 63.23 1416 69.11 1459 75.22 1501 81.38 1542 87.57 1622 100.22 1700 113.30 1776 126.81 1851 140.83
33516 3600 1402 67.50 1444 73.66 1485 79.89 1526 86.35 1565 92.66 1643 105.84 1718 119.19 1792 133.10 1864 147.36
35378 3800 1433 72.11 1473 78.36 1513 84.85 1552 91.40 1590 97.97 1666 111.69 1739 125.53 1810 139.64 1879 154.00
37240 4000 1466 77.12 1504 83.44 1543 90.16 1580 96.77 1617 103.58 1690 117.59 1761 131.91 1830 146.45 1898 161.42
39102 4200 1501 82.58 1537 88.95 1574 95.72 1610 102.53 1646 109.56 1717 124.02 1785 138.58 1853 153.80 1918 168.91
40964 4400 1536 88.20 1572 94.96 1607 101.74 1642 108.75 1676 115.77 1744 130.42 1811 145.59 1876 160.97 1940 176.72
42826 4600 1573 94.34 1608 101.32 1641 108.11 1675 115.30 1708 122.49 1774 137.49 1838 152.78 1902 168.78 1964 184.90
44688 4800 1612 101.03 1644 107.86 1677 115.04 1709 122.21 1741 129.56 1805 144.87 1867 160.47 1929 176.79 1989 193.21
46550 5000 1651 107.94 1682 114.98 1714 122.37 1745 129.72 1776 137.25 1837 152.60 1898 168.73 1957 185.05 2016 202.03
48412 5200 1691 115.28 1721 122.53 1752 130.13 1782 137.67 1812 145.36 1871 161.00 1929 177.09 1987 193.91 2044 211.11
50274 5400 1731 122.88 1761 130.53 1790 138.11 1819 145.81 1848 153.67 1906 169.85 1962 186.15 2018 203.15 2073 220.54
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
31654 3400 1925 155.35 1996 169.91
33516 3600 1934 161.83 2004 176.96 2072 192.27
35378 3800 1948 169.11 2015 184.39 2081 200.00 2146 215.97 2210 232.33
37240 4000 1964 176.58 2029 192.17 2092 207.86 2156 224.42 2218 240.97 2279 257.83 2339 275.00
39102 4200 1982 184.38 2045 200.22 2107 216.43 2168 233.00 2228 249.81 2288 267.18 2346 284.43 2404 302.29 2461 320.40
40964 4400 2003 192.80 2064 208.92 2124 225.35 2183 242.08 2241 259.11 2299 276.73 2356 294.51 2412 312.44
42826 4600 2025 201.33 2084 217.72 2143 234.69 2200 251.59 2257 269.07 2313 286.81 2368 304.78 2423 323.25
44688 4800 2049 210.26 2107 227.26 2163 244.13 2219 261.54 2275 279.52 2329 297.32 2383 315.70 2436 334.27
46550 5000 2074 219.34 2130 236.59 2186 254.38 2240 271.97 2294 290.08 2347 308.35 2399 326.75 2451 345.69
48412 5200 2100 228.64 2155 246.43 2210 264.77 2263 282.92 2315 301.17 2367 319.91 2418 338.76
50274 5400 2128 238.56 2181 256.51 2234 275.00 2287 294.04 2338 312.82 2388 331.65 2438 350.94
52136 5600 2157 248.83 2209 267.24 2261 286.24 2312 305.39 2362 324.66 2411 343.98 2460 363.76
53998 5800 2187 259.51 2238 278.36 2288 297.42 2338 317.03 2387 336.74 2435 356.53
55860 6000 2218 270.65 2267 289.54 2316 308.99 2365 329.01 2413 349.15 2460 369.36
57722 6200 2251 282.69 2299 301.96 2346 321.42 2393 341.41 2440 361.94
59584 6400 2284 294.95 2331 314.56 2377 334.36 2423 354.72
Underlined numbers indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
Design 14 Design 17 Design 22 Design 26
1329 1802 2088 2467
13 Twin City Bulletin 400

Performance Data
Max. RPM
Design 14 Design 17 Design 22 Design 26
1202 1631 1888 2231
445 BCS Outlet Area: 11.39 ft 2 Wheel Diameter.: 44.5" Tip Speed (FPM): 11.65 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
13668 1200 412 2.81 522 5.46 621 8.50
14807 1300 428 3.14 532 5.90 626 9.03
15946 1400 444 3.49 543 6.36 634 9.64 717 13.16
17085 1500 461 3.88 556 6.88 642 10.23 723 13.91 799 17.84
18224 1600 479 4.31 569 7.40 652 10.89 730 14.67 803 18.69
19363 1700 498 4.79 583 7.96 663 11.58 738 15.46 809 19.61 877 24.01
20502 1800 517 5.31 598 8.58 675 12.30 748 16.36 816 20.55 882 25.08 946 29.86
21641 1900 536 5.86 614 9.26 688 13.08 759 17.29 825 21.62 889 26.24 950 31.04 1010 36.13
22780 2000 556 6.48 631 10.01 702 13.92 770 18.20 835 22.73 896 27.36 956 32.33 1014 37.49 1070 42.82
25058 2200 597 7.87 666 11.64 731 15.69 795 20.20 856 24.97 915 29.97 971 35.06 1025 40.32 1079 45.96
27336 2400 639 9.47 702 13.45 764 17.82 823 22.45 880 27.38 936 32.65 990 38.08 1042 43.63 1092 49.29
29614 2600 681 11.27 741 15.60 798 20.14 853 24.93 907 30.07 960 35.55 1011 41.19 1061 47.05 1109 52.96
31892 2800 724 13.32 780 17.94 834 22.75 886 27.79 937 33.12 987 38.77 1035 44.58 1083 50.73 1129 56.92
34170 3000 768 15.68 821 20.64 871 25.62 920 30.89 968 36.40 1015 42.16 1062 48.33 1107 54.60 1152 61.19
36448 3200 812 18.29 862 23.57 909 28.79 956 34.35 1001 40.03 1046 46.04 1090 52.28 1133 58.74 1176 65.54
38726 3400 856 21.18 904 26.83 949 32.39 993 38.12 1036 44.08 1079 50.33 1120 56.61 1162 63.40 1202 70.20
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
27336 2400 1141 55.17 1190 61.37 1237 67.57 1284 74.11
29614 2600 1156 59.06 1202 65.34 1247 71.78 1292 78.51 1336 85.36
31892 2800 1174 63.25 1218 69.72 1261 76.33 1304 83.24 1345 90.08 1427 104.51
34170 3000 1195 67.77 1237 74.45 1279 81.41 1319 88.26 1359 95.40 1437 110.10 1514 125.58 1588 141.34
36448 3200 1218 72.49 1258 79.37 1298 86.50 1337 93.69 1376 101.14 1451 116.18 1524 131.81 1596 148.11 1666 164.81
38726 3400 1242 77.31 1282 84.73 1320 92.02 1358 99.57 1395 107.13 1468 122.76 1538 138.63 1607 155.24 1675 172.45
41004 3600 1269 82.68 1306 90.02 1344 97.85 1380 105.50 1416 113.40 1486 129.38 1554 145.75 1621 162.79 1686 180.19
43282 3800 1297 88.31 1333 95.93 1369 103.84 1404 111.78 1439 119.98 1507 136.58 1573 153.50 1637 170.69 1700 188.45
45560 4000 1327 94.47 1361 102.13 1396 110.30 1430 118.51 1463 126.73 1529 143.87 1593 161.33 1656 179.30 1717 197.46
47838 4200 1358 101.02 1391 108.91 1424 117.07 1457 125.52 1489 133.97 1553 151.61 1615 169.56 1676 188.02 1735 206.57
50116 4400 1390 107.97 1422 116.10 1454 124.48 1486 133.15 1517 141.81 1578 159.59 1639 178.29 1698 197.19 1755 216.15
52394 4600 1424 115.60 1455 123.98 1485 132.33 1516 141.20 1546 150.05 1605 168.20 1663 186.94 1721 206.56 1777 226.26
54672 4800 1458 123.47 1488 132.09 1518 140.93 1547 149.72 1576 158.74 1633 177.20 1689 196.26 1745 216.19 1800 236.57
56950 5000 1494 132.10 1522 140.70 1551 149.77 1579 158.75 1607 167.94 1662 186.68 1717 206.34 1771 226.54 1824 247.18
59228 5200 1530 141.03 1558 150.14 1585 159.14 1612 168.32 1639 177.68 1693 197.03 1746 216.92 1798 237.33 1849 258.15
61506 5400 1567 150.56 1594 159.88 1620 169.09 1646 178.45 1673 188.32 1724 207.61 1775 227.68 1826 248.62 1876 270.00
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
38726 3400 1741 189.92 1806 208.00
41004 3600 1750 198.13 1813 216.53 1874 235.07
43282 3800 1762 206.79 1823 225.64 1882 244.47 1941 264.09 1999 284.15
45560 4000 1776 215.75 1835 234.89 1893 254.49 1950 274.39 2006 294.60 2061 315.13 2116 336.48
47838 4200 1793 225.54 1850 244.93 1906 264.72 1961 284.92 2015 305.38 2069 326.49 2122 347.85 2175 369.96 2226 391.85
50116 4400 1812 235.84 1867 255.49 1921 275.47 1975 296.22 2027 316.84 2079 338.17 2131 360.13 2182 382.26
52394 4600 1832 246.29 1886 266.63 1938 286.80 1990 307.66 2042 329.27 2092 350.65 2142 372.76 2191 394.95
54672 4800 1853 256.91 1906 277.93 1957 298.74 2008 320.22 2058 341.90 2107 363.76 2155 385.79 2203 408.53
56950 5000 1876 268.17 1927 289.43 1978 311.36 2027 332.98 2076 355.22 2123 377.09 2171 400.13 2217 422.73
59228 5200 1900 279.74 1950 301.62 1999 323.72 2047 345.95 2095 368.79 2141 391.17 2187 414.14
61506 5400 1925 291.72 1974 314.18 2022 336.86 2069 359.69 2115 382.60 2161 406.07 2206 429.57
63784 5600 1951 304.16 1999 327.15 2045 349.87 2091 373.23 2137 397.22 2181 420.69 2225 444.69
66062 5800 1979 317.62 2025 340.63 2070 363.84 2115 387.71 2159 411.64 2203 436.18
68340 6000 2007 331.24 2052 354.70 2096 378.34 2140 402.67 2183 427.08 2226 452.10
70618 6200 2037 346.04 2080 369.40 2123 393.47 2165 417.65 2207 442.45
72896 6400 2067 361.10 2109 384.82 2151 409.28 2192 433.84
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
14 Twin City Bulletin 400

Performance Data
Max. RPM
Design 14 Design 17 Design 22 Design 26
1092 1481 1780 2027
490 BCS Outlet Area: 13.80 ft 2 Wheel Diameter.: 49" Tip Speed (FPM): 12.83 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
16560 1200 374 3.40 474 6.62 564 10.31
17940 1300 388 3.79 483 7.15 569 10.97
19320 1400 403 4.22 493 7.71 575 11.64 652 16.01
20700 1500 419 4.71 504 8.30 583 12.40 656 16.82 726 21.66
22080 1600 435 5.22 516 8.94 592 13.19 663 17.79 730 22.72
23460 1700 452 5.80 529 9.63 602 14.03 670 18.73 735 23.80 797 29.16
24840 1800 469 6.42 543 10.40 613 14.92 679 19.80 741 24.91 801 30.40 859 36.18
26220 1900 487 7.12 557 11.19 625 15.87 689 20.93 749 26.18 807 31.77 863 37.65 917 43.76
27600 2000 505 7.86 573 12.14 637 16.83 699 22.04 758 27.52 814 33.20 868 39.16 921 45.46 972 51.94
30360 2200 542 9.53 604 14.06 664 19.04 722 24.49 777 30.22 830 36.20 882 42.52 931 48.89 980 55.72
33120 2400 580 11.47 637 16.27 693 21.53 747 27.17 799 33.17 850 39.57 899 46.15 946 52.84 992 59.80
35880 2600 618 13.63 672 18.83 724 24.35 775 30.27 824 36.50 872 43.12 918 49.91 963 56.94 1007 64.18
38640 2800 657 16.12 708 21.72 757 27.54 804 33.62 851 40.17 896 46.95 940 54.05 983 61.40 1025 68.94
41400 3000 697 18.97 745 24.96 791 31.07 835 37.39 879 44.12 922 51.16 964 58.52 1005 66.13 1046 74.14
44160 3200 737 22.14 782 28.49 826 34.98 868 41.63 909 48.53 950 55.83 990 63.40 1029 71.23 1068 79.46
46920 3400 777 25.65 820 32.42 861 39.17 901 46.10 940 53.30 979 60.85 1017 68.61 1055 76.80 1091 84.97
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
33120 2400 1036 66.83 1080 74.23 1124 82.03 1166 89.81
35880 2600 1050 71.63 1092 79.29 1133 87.13 1173 95.08 1213 103.38
38640 2800 1066 76.64 1106 84.48 1145 92.47 1184 100.84 1222 109.32 1296 126.69
41400 3000 1085 82.10 1123 90.15 1161 98.54 1198 107.03 1234 115.59 1305 133.45 1375 152.22 1442 171.25
44160 3200 1106 87.85 1143 96.35 1179 104.92 1214 113.51 1249 122.42 1318 140.91 1384 159.76 1449 179.36 1513 199.76
46920 3400 1128 93.75 1164 102.65 1199 111.63 1233 120.62 1267 129.91 1333 148.75 1397 168.13 1459 188.01 1521 208.95
49680 3600 1152 100.13 1186 109.13 1220 118.46 1253 127.82 1286 137.48 1350 157.00 1411 176.57 1472 197.27 1531 218.35
52440 3800 1177 106.84 1210 116.15 1243 125.81 1275 135.51 1307 145.51 1368 165.36 1428 185.87 1487 207.05 1544 228.49
55200 4000 1204 114.23 1236 123.83 1267 133.48 1298 143.47 1329 153.77 1389 174.58 1447 195.70 1503 216.96 1559 239.21
57960 4200 1233 122.40 1263 131.97 1293 141.88 1323 152.13 1352 162.34 1410 183.66 1467 205.70 1522 227.89 1576 250.57
60720 4400 1262 130.81 1291 140.64 1320 150.77 1349 161.25 1377 171.69 1433 193.46 1488 215.94 1541 238.57 1594 262.13
63480 4600 1293 140.10 1321 150.21 1348 160.24 1376 170.91 1403 181.53 1457 203.68 1510 226.53 1562 249.97 1613 273.89
66240 4800 1324 149.68 1351 160.05 1378 170.67 1404 181.19 1431 192.37 1483 214.84 1534 238.01 1584 261.74 1634 286.45
69000 5000 1356 159.91 1382 170.53 1408 181.39 1434 192.50 1459 203.46 1509 226.18 1559 250.03 1608 274.49 1656 299.41
71760 5200 1389 170.83 1414 181.71 1439 192.80 1464 204.11 1488 215.24 1537 238.66 1585 262.69 1632 287.29 1679 312.88
74520 5400 1422 182.15 1447 193.63 1471 204.94 1495 216.46 1518 227.74 1565 251.41 1612 276.06 1658 301.28 1703 326.94
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
46920 3400 1581 230.15 1640 252.04
49680 3600 1589 240.02 1646 262.21 1702 284.97
52440 3800 1600 250.57 1655 273.20 1709 296.23 1763 320.23 1815 344.15
55200 4000 1613 261.57 1666 284.47 1719 308.38 1771 332.63 1822 357.20 1872 382.12 1921 407.38
57960 4200 1628 273.23 1680 296.83 1731 320.91 1781 345.42 1830 370.17 1879 395.73 1927 421.52 1975 448.24 2021 474.52
60720 4400 1645 285.59 1695 309.42 1745 334.16 1793 358.69 1841 384.15 1888 409.85 1935 436.31 1981 462.89 2027 490.30
63480 4600 1663 298.18 1712 322.77 1760 347.64 1807 372.79 1854 398.83 1900 425.12 1945 451.63 1990 478.86
66240 4800 1683 311.56 1730 336.38 1777 361.98 1823 387.79 1868 413.78 1913 440.59 1957 467.58 2001 495.44
69000 5000 1703 324.71 1750 350.86 1796 377.24 1840 403.10 1885 430.38 1928 457.08 1971 484.57 2013 512.12
71760 5200 1725 338.86 1770 365.12 1815 392.19 1859 419.39 1902 446.64 1944 473.92 1986 501.92
74520 5400 1748 353.56 1792 380.45 1835 407.53 1878 435.38 1920 463.27 1962 491.87 2003 520.42
77280 5600 1772 368.89 1815 396.38 1857 424.04 1899 452.50 1940 481.01 1981 510.22 2021 539.36
80040 5800 1796 384.30 1838 412.31 1879 440.50 1920 469.49 1961 499.27 2000 528.26
82800 6000 1822 401.16 1863 429.67 1903 458.35 1943 487.85 1982 517.39 2021 547.65
85560 6200 1849 418.94 1888 447.19 1927 476.30 1966 506.24 2004 536.18
88320 6400 1876 437.01 1915 466.37 1953 495.89 1990 525.45 2027 555.78
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
15 Twin City Bulletin 400

Performance Data
Max. RPM
Design 14 Design 17 Design 22 Design 26
986 1338 1549 1831
542 BCS Outlet Area: 16.92 ft 2 Wheel Diameter.: 54.25" Tip Speed (FPM): 14.20 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
20304 1200 338 4.18 428 8.11 509 12.60
21996 1300 351 4.66 437 8.81 514 13.46
23688 1400 364 5.18 446 9.49 520 14.32 589 19.64
25380 1500 378 5.75 456 10.22 527 15.23 593 20.67 656 26.59
27072 1600 393 6.41 466 10.95 535 16.20 599 21.83 659 27.81
28764 1700 408 7.10 478 11.82 544 17.22 606 23.05 664 29.19 720 35.77
30456 1800 424 7.89 491 12.79 554 18.32 613 24.24 670 30.63 724 37.34 776 44.37
32148 1900 440 8.73 504 13.79 564 19.40 622 25.62 677 32.16 729 38.96 779 46.07 828 53.60
33840 2000 456 9.62 517 14.83 576 20.70 631 26.97 684 33.64 735 40.67 784 48.01 832 55.76 878 63.69
37224 2200 490 11.71 546 17.27 600 23.37 652 30.01 702 37.08 750 44.43 796 52.00 841 59.96 885 68.27
40608 2400 524 14.06 576 20.00 626 26.40 675 33.35 722 40.72 768 48.56 812 56.57 854 64.67 896 73.30
43992 2600 559 16.78 607 23.09 654 29.85 700 37.10 744 44.69 788 52.94 830 61.37 870 69.84 910 78.79
47376 2800 594 19.81 640 26.69 684 33.80 726 41.18 768 49.11 809 57.49 849 66.25 888 75.30 926 84.56
50760 3000 630 23.30 673 30.61 714 38.01 755 45.98 794 54.09 833 62.76 871 71.80 908 81.12 944 90.66
54144 3200 666 27.18 707 35.02 746 42.86 784 51.03 821 59.48 858 68.42 894 77.67 930 87.47 964 97.20
57528 3400 702 31.47 741 39.80 778 48.07 814 56.55 850 65.56 885 74.78 919 84.22 953 94.17 986 104.34
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
40608 2400 936 81.99 976 91.15 1015 100.50 1053 110.05
43992 2600 948 87.70 986 97.10 1023 106.70 1060 116.73 1095 126.52
47376 2800 963 93.99 999 103.58 1035 113.63 1069 123.48 1104 134.12 1171 155.48
50760 3000 980 100.64 1015 110.74 1049 120.92 1082 131.18 1115 141.85 1179 163.71 1242 186.63 1303 210.21
54144 3200 999 107.70 1032 117.98 1065 128.65 1097 139.33 1129 150.41 1190 172.55 1250 195.81 1309 219.99 1367 245.11
57528 3400 1019 114.97 1051 125.70 1083 136.85 1114 147.99 1144 159.08 1204 182.34 1262 206.21 1318 230.58 1374 256.27
60912 3600 1040 122.56 1071 133.68 1102 145.23 1132 156.79 1162 168.73 1219 192.29 1275 216.73 1329 241.54 1383 267.77
64296 3800 1064 131.29 1093 142.41 1123 154.34 1152 166.27 1180 178.14 1236 202.89 1290 227.95 1343 253.76 1394 279.75
67680 4000 1088 140.21 1116 151.63 1145 163.88 1173 176.13 1200 188.31 1254 213.70 1307 239.91 1358 266.22 1408 293.16
71064 4200 1114 150.16 1141 161.86 1168 173.97 1195 186.49 1221 198.92 1274 225.37 1325 252.13 1375 279.54 1423 306.85
74448 4400 1140 160.39 1166 172.36 1192 184.69 1218 197.43 1244 210.58 1294 236.96 1344 264.70 1392 292.52 1440 321.50
77832 4600 1168 171.78 1193 184.04 1218 196.63 1243 209.58 1268 222.93 1316 249.66 1364 277.76 1411 306.52 1457 335.81
81216 4800 1196 183.53 1220 196.05 1245 209.38 1268 222.02 1292 235.52 1339 263.06 1386 292.03 1431 321.03 1476 351.22
84600 5000 1225 196.11 1248 208.90 1272 222.47 1295 235.83 1318 249.50 1363 277.26 1408 306.40 1452 336.19 1496 367.21
87984 5200 1255 209.60 1277 222.64 1300 236.46 1322 250.00 1344 263.82 1388 292.37 1432 322.26 1474 352.10 1517 383.89
91368 5400 1285 223.59 1307 237.35 1329 251.40 1350 265.12 1372 279.70 1414 308.45 1456 338.39 1497 368.89 1538 400.60
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
57528 3400 1428 282.14 1481 308.80
60912 3600 1435 294.10 1487 321.64 1538 349.83
64296 3800 1445 307.07 1495 335.03 1544 363.43 1592 392.28 1640 422.40
67680 4000 1457 320.72 1505 348.88 1553 378.30 1599 407.30 1645 437.37 1691 468.59 1735 499.35
71064 4200 1471 335.32 1517 363.58 1563 393.03 1608 422.93 1653 453.88 1697 485.00 1741 517.19 1784 549.63 1826 582.29
74448 4400 1486 350.23 1531 379.32 1576 409.54 1620 440.12 1663 471.05 1706 503.07 1748 535.11 1790 568.14 1831 601.23
77832 4600 1502 365.46 1547 396.18 1590 426.43 1633 457.72 1675 489.28 1716 521.02 1757 553.86 1798 587.62
81216 4800 1520 381.82 1563 412.67 1605 443.70 1647 475.75 1688 507.93 1728 540.23 1768 573.58 1807 606.99
84600 5000 1539 398.66 1581 430.39 1622 462.27 1662 494.19 1702 527.04 1742 560.88 1780 593.75 1819 628.62
87984 5200 1558 415.32 1599 447.80 1640 481.31 1679 514.02 1718 547.57 1756 581.08 1794 615.47 1831 649.78
91368 5400 1579 433.52 1619 466.71 1658 500.08 1697 534.39 1735 568.67 1772 602.82 1809 637.78
94752 5600 1600 451.73 1639 485.56 1677 519.52 1715 554.47 1752 589.37 1789 625.16 1825 660.71
98136 5800 1623 471.77 1660 505.28 1698 540.75 1735 576.29 1771 611.77 1807 648.14
101520 6000 1646 492.03 1683 526.95 1719 561.99 1755 598.04 1790 634.00 1825 670.84
104904 6200 1670 513.46 1706 548.83 1741 584.33 1776 620.81 1810 657.18
108288 6400 1695 536.19 1730 571.98 1764 607.84 1798 644.72 1831 681.44
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
16 Twin City Bulletin 400

Performance Data
Max. RPM
Design 14 Design 17 Design 22 Design 26
891 1082 1401 1655
600 BCS Outlet Area: 20.70 ft 2 Wheel Diameter.: 60" Tip Speed (FPM): 15.71 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
24840 1200 306 5.13 387 9.92 461 15.50
26910 1300 317 5.69 395 10.77 464 16.38
28980 1400 329 6.32 403 11.59 470 17.50 532 23.95
31050 1500 342 7.05 412 12.48 476 18.58 536 25.26 593 32.50
33120 1600 355 7.82 422 13.45 484 19.85 541 26.61 596 34.05
35190 1700 369 8.69 432 14.44 492 21.08 548 28.21 600 35.65 651 43.76
37260 1800 383 9.62 444 15.65 501 22.42 555 29.77 606 37.51 654 45.55 701 54.14
39330 1900 398 10.69 455 16.80 510 23.74 563 31.44 612 39.32 659 47.63 705 56.52 749 65.66
41400 2000 412 11.75 468 18.20 520 25.21 571 33.07 619 41.27 665 49.84 709 58.76 752 68.14 794 77.96
45540 2200 443 14.33 494 21.17 542 28.50 590 36.79 635 45.41 678 54.32 720 63.69 761 73.52 800 83.46
49680 2400 474 17.23 521 24.50 566 32.29 610 40.73 653 49.85 694 59.29 734 69.14 772 79.06 810 89.63
53820 2600 505 20.47 549 28.27 592 36.64 633 45.40 673 54.74 712 64.63 750 74.93 787 85.56 823 96.45
57960 2800 537 24.23 579 32.70 618 41.25 657 50.50 695 60.23 732 70.48 768 81.15 803 92.14 837 103.34
62100 3000 569 28.41 609 37.53 646 46.58 682 56.08 718 66.19 753 76.72 787 87.65 821 99.24 854 111.08
66240 3200 602 33.22 639 42.78 674 52.31 709 62.45 743 72.96 776 83.77 808 94.89 840 106.66 872 119.06
70380 3400 635 38.54 670 48.68 704 58.93 736 69.17 768 80.02 800 91.41 831 103.04 861 114.92 891 127.41
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
49680 2400 846 100.19 882 111.33 918 123.05 952 134.59
53820 2600 857 107.22 892 118.98 925 130.54 958 142.61 991 155.21
57960 2800 871 115.09 903 126.59 935 138.63 967 151.26 998 163.96 1059 190.31
62100 3000 886 123.07 918 135.58 948 147.70 978 160.31 1008 173.45 1066 200.26 1123 228.33 1178 257.07
66240 3200 903 131.63 933 144.27 963 157.40 992 170.51 1020 183.56 1076 211.10 1130 239.41 1184 269.42 1236 299.85
70380 3400 921 140.48 950 153.63 979 167.29 1007 180.90 1035 194.95 1088 222.68 1141 252.21 1192 282.29 1242 313.25
74520 3600 941 150.23 969 163.84 996 177.45 1024 192.07 1050 206.02 1102 235.11 1153 265.25 1202 295.74 1250 327.19
78660 3800 962 160.58 989 174.59 1015 188.58 1041 203.04 1067 217.96 1118 248.49 1167 279.28 1214 310.19 1261 342.69
82800 4000 984 171.65 1010 186.00 1035 200.31 1060 215.09 1085 230.35 1134 261.53 1182 293.66 1228 325.78 1273 358.56
86940 4200 1007 183.55 1032 198.19 1056 212.76 1080 227.81 1104 243.33 1152 275.74 1198 308.40 1243 341.76 1287 375.68
91080 4400 1031 196.34 1055 211.27 1078 226.07 1102 241.98 1125 257.73 1170 289.86 1215 323.64 1259 358.18 1302 393.27
95220 4600 1056 210.08 1079 225.32 1101 240.33 1124 256.44 1146 272.34 1190 305.48 1234 340.35 1276 375.14 1318 411.35
99360 4800 1081 224.25 1103 239.75 1125 255.64 1147 271.94 1169 288.69 1211 322.03 1253 357.07 1294 392.83 1335 430.06
103500 5000 1108 240.14 1129 255.93 1150 272.06 1171 288.54 1192 305.43 1233 339.66 1273 374.73 1313 411.38 1353 449.56
107640 5200 1135 256.56 1155 272.60 1175 288.92 1196 306.33 1216 323.35 1255 357.64 1294 393.49 1333 430.95 1371 468.95
111780 5400 1162 273.59 1182 290.51 1201 307.02 1221 324.60 1240 341.70 1279 377.75 1317 414.42 1354 451.69 1391 490.44
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
70380 3400 1291 345.02 1339 377.70
74520 3600 1298 360.21 1344 393.03 1390 427.39
78660 3800 1307 376.05 1352 410.08 1396 444.55 1440 480.46 1482 515.86
82800 4000 1317 392.00 1361 426.99 1404 462.61 1446 498.50 1488 535.72 1529 573.29 1569 611.17
86940 4200 1330 410.16 1372 445.13 1413 480.57 1454 517.47 1495 555.68 1535 594.03 1574 632.50 1613 672.31 1651 712.30
91080 4400 1344 428.81 1385 464.75 1425 501.01 1465 538.67 1504 576.67 1542 614.79 1580 654.01 1618 694.42
95220 4600 1358 447.00 1398 483.86 1438 522.05 1476 559.36 1514 597.95 1552 637.91 1589 678.02 1625 717.92
99360 4800 1374 466.71 1413 504.58 1452 543.69 1489 581.77 1526 621.05 1563 661.62 1598 700.90 1634 742.75
103500 5000 1391 487.11 1429 525.92 1467 565.97 1503 604.86 1539 644.84 1575 686.03 1610 727.12 1644 768.03
107640 5200 1409 508.37 1446 548.04 1482 587.78 1518 628.64 1553 669.36 1588 711.20 1622 752.81
111780 5400 1428 530.65 1464 571.08 1499 611.58 1534 653.21 1569 695.99 1602 737.14 1636 780.69
115920 5600 1447 552.96 1482 594.04 1517 636.39 1551 678.71 1585 722.17 1618 765.34 1650 808.06
120060 5800 1467 576.53 1501 618.18 1535 661.10 1568 703.95 1601 747.96 1634 793.08
124200 6000 1488 601.54 1521 643.68 1554 687.10 1587 731.81 1619 776.30 1651 821.94
128340 6200 1510 628.11 1542 670.67 1574 714.54 1606 759.68 1637 804.56
132480 6400 1533 656.45 1564 699.37 1595 743.60 1626 789.07
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
17 Twin City Bulletin 400

Performance Data
Max. RPM
660 BCS Outlet Area: 25.04 ft2 Wheel Diameter.: 66" Tip Speed (FPM): 17.28 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
30048 1200 278 6.19 352 12.02 419 18.74
32552 1300 288 6.87 359 13.02 422 19.84
35056 1400 299 7.65 366 13.98 427 21.13 484 29.04
37560 1500 311 8.54 375 15.15 433 22.52 487 30.51 539 39.30
40064 1600 323 9.48 383 16.20 440 24.01 492 32.23 542 41.23
42568 1700 335 10.48 393 17.51 447 25.46 498 34.10 546 43.26 591 52.72
45072 1800 348 11.63 403 18.85 455 27.04 504 35.90 550 45.16 595 55.24 638 65.72
47576 1900 361 12.85 414 20.38 464 28.79 511 37.86 556 47.48 599 57.60 641 68.40 681 79.46
50080 2000 375 14.27 425 21.96 473 30.55 519 39.99 563 50.00 604 60.14 644 70.92 683 82.21 721 94.00
55088 2200 402 17.24 449 25.60 493 34.54 536 44.43 577 54.87 617 65.93 655 77.21 691 88.63 727 100.86
60096 2400 430 20.71 473 29.52 515 39.17 555 49.40 594 60.43 631 71.77 667 83.56 702 95.73 736 108.28
65104 2600 459 24.76 499 34.18 538 44.29 575 54.80 612 66.30 647 78.10 682 90.74 715 103.32 748 116.61
70112 2800 488 29.28 526 39.49 562 49.97 597 61.02 631 72.60 665 85.11 698 98.12 730 111.48 761 125.08
75120 3000 517 34.32 553 45.26 587 56.29 620 67.86 653 80.19 684 92.61 716 106.30 746 119.90 776 134.21
80128 3200 547 40.13 581 51.79 613 63.38 644 75.38 675 88.10 705 101.16 735 115.03 764 129.24 793 144.21
85136 3400 577 46.57 609 58.88 640 71.31 669 83.67 698 96.75 727 110.48 755 124.46 783 139.20 810 154.16
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
60096 2400 769 121.18 802 134.78 834 148.58 865 162.57
65104 2600 779 129.68 810 143.47 841 157.99 871 172.59 900 187.21
70112 2800 792 139.34 821 153.21 850 167.73 879 182.94 907 198.19 962 229.73
75120 3000 806 149.21 834 163.72 862 178.82 889 193.90 916 209.61 969 242.22 1021 276.31 1071 311.09
80128 3200 821 159.32 848 174.45 875 190.14 902 206.42 928 222.61 978 255.26 1028 290.26 1076 325.63 1123 362.15
85136 3400 837 169.81 864 186.12 890 202.41 915 218.55 940 235.20 989 269.34 1037 304.90 1083 340.93 1129 378.89
90144 3600 855 181.49 881 198.31 906 215.09 930 231.71 955 249.63 1002 284.62 1048 320.76 1093 358.07 1137 396.52
95152 3800 874 193.94 899 211.19 923 228.38 947 246.17 970 263.72 1016 300.33 1060 337.04 1104 375.67 1146 414.22
100160 4000 894 207.32 918 224.92 941 242.44 964 260.55 986 278.41 1031 316.53 1074 354.77 1116 393.77 1157 433.51
105168 4200 915 221.77 938 239.67 960 257.43 982 275.80 1004 294.75 1047 333.38 1089 373.06 1130 413.50 1170 454.54
110176 4400 937 237.37 959 255.57 980 273.54 1001 292.08 1022 311.19 1064 351.08 1105 392.07 1144 432.75 1183 475.06
115184 4600 960 254.21 981 272.72 1001 290.89 1022 310.46 1042 329.70 1082 369.82 1121 410.92 1160 453.90 1198 497.49
120192 4800 983 271.58 1003 290.35 1023 309.58 1043 329.32 1062 348.60 1101 389.76 1139 431.94 1176 474.87 1213 519.54
125200 5000 1007 290.34 1026 309.35 1045 328.76 1064 348.61 1083 368.92 1121 411.09 1157 453.10 1194 498.22 1229 542.61
130208 5200 1031 309.72 1050 329.86 1068 349.43 1087 370.40 1105 390.78 1141 432.86 1177 476.89 1212 521.69 1247 568.30
135216 5400 1056 330.72 1074 351.00 1092 371.70 1110 392.78 1127 413.17 1162 456.23 1197 501.12 1231 546.66 1264 592.66
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
85136 3400 1174 417.81 1217 456.64
90144 3600 1180 435.81 1222 475.71 1264 517.52
95152 3800 1188 454.76 1229 496.03 1269 537.72 1309 581.16 1348 625.12
100160 4000 1198 475.14 1237 516.27 1276 559.20 1315 603.74 1353 648.53 1390 693.58 1426 738.85
105168 4200 1209 496.13 1247 538.21 1285 582.05 1322 626.32 1359 672.15 1395 717.98 1431 765.37 1466 812.80 1501 861.93
110176 4400 1221 517.79 1259 562.16 1295 605.53 1331 650.53 1367 697.27 1402 744.10 1437 792.30 1471 840.27
115184 4600 1235 541.44 1271 585.55 1307 631.22 1342 677.04 1376 722.89 1410 770.31 1444 819.37 1477 868.09
120192 4800 1249 564.58 1285 611.16 1319 656.32 1354 704.44 1387 750.96 1420 798.95 1453 848.47 1485 897.81
125200 5000 1265 590.03 1299 636.22 1333 683.81 1366 731.24 1399 780.05 1431 828.61 1463 878.58 1495 930.07
130208 5200 1281 615.23 1314 662.29 1348 712.33 1380 760.62 1412 810.20 1444 861.13 1475 911.66
135216 5400 1298 641.80 1330 689.57 1363 740.42 1395 791.14 1426 841.45 1457 893.06 1487 944.06
140224 5600 1315 668.37 1347 718.33 1379 769.86 1410 821.22 1440 872.14 1471 926.20 1500 977.69
145232 5800 1334 698.18 1365 748.72 1395 799.13 1426 852.74 1456 906.02 1485 958.71
150240 6000 1353 728.29 1383 779.29 1413 831.88 1442 884.13 1471 937.76 1500 992.70
155248 6200 1373 760.48 1402 811.85 1431 864.77 1460 919.19 1488 973.13
160256 6400 1393 793.21 1422 846.56 1450 899.74 1478 954.43
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
Design 14 Design 17 Design 22 Design 26
810 984 1273 1504
18 Twin City Bulletin 400

Performance Data
Max. RPM
730 BCS Outlet Area: 30.63 ft 2 Wheel Diameter.: 73" Tip Speed (FPM): 19.11 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
36756 1200 251 7.54 318 14.67 379 22.95
39819 1300 261 8.46 324 15.84 382 24.37
42882 1400 270 9.32 331 17.12 386 25.84 437 35.38
45945 1500 281 10.43 339 18.53 391 27.45 441 37.50 487 47.99
49008 1600 292 11.60 347 19.94 398 29.42 445 39.48 490 50.43
52071 1700 303 12.83 355 21.36 404 31.12 450 41.64 493 52.71 535 64.74
55134 1800 315 14.28 365 23.18 412 33.24 456 44.01 498 55.49 538 67.59 576 80.05
58197 1900 327 15.81 374 24.87 419 35.10 462 46.31 503 58.19 542 70.63 579 83.45 615 96.88
61260 2000 339 17.45 384 26.81 428 37.47 469 48.85 509 61.16 546 73.54 583 87.09 618 100.81 652 115.06
67386 2200 364 21.19 406 31.33 446 42.34 484 54.15 522 67.25 557 80.29 592 94.37 625 108.56 658 123.79
73512 2400 389 25.39 428 36.21 465 47.73 501 60.15 537 73.91 571 88.04 603 102.20 635 117.28 666 132.80
79638 2600 415 30.29 451 41.78 486 54.05 520 67.09 553 80.97 585 95.56 616 110.68 647 126.73 676 142.48
85764 2800 441 35.77 475 48.14 508 61.09 540 74.76 571 89.05 601 103.99 631 119.99 660 136.39 688 153.00
91890 3000 468 42.15 500 55.38 531 68.98 561 83.22 590 97.91 619 113.62 647 129.84 675 147.03 702 164.48
98016 3200 495 49.23 525 63.26 554 77.44 582 92.10 610 107.64 638 124.11 664 140.40 691 158.29 717 176.45
104142 3400 522 57.08 551 72.19 578 86.96 605 102.44 631 118.32 657 134.98 683 152.53 708 170.36 733 189.12
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
73512 2400 696 148.71 725 164.81 754 181.74 782 198.83
79638 2600 705 159.12 733 175.99 760 193.00 787 210.74 814 229.28
85764 2800 716 170.43 743 187.98 769 205.60 795 224.04 820 242.43 870 281.27
91890 3000 728 182.00 754 200.26 779 218.47 804 237.43 828 256.27 876 296.23 923 337.91 968 380.20
98016 3200 742 194.69 767 213.68 791 232.53 815 252.05 839 272.32 884 312.04 929 354.60 973 398.57 1016 443.91
104142 3400 757 207.95 781 227.56 805 247.93 828 268.08 850 287.87 894 329.32 937 372.33 979 416.87 1021 463.85
110268 3600 773 222.01 796 242.13 819 263.02 841 283.65 863 304.93 906 348.28 947 391.77 988 437.78 1028 485.11
116394 3800 790 237.09 812 257.60 834 278.90 856 300.95 877 322.63 918 366.72 959 413.15 998 459.38 1036 506.58
122520 4000 808 253.37 830 275.19 851 296.83 871 318.13 892 341.21 932 387.06 971 433.98 1009 481.74 1046 530.25
128646 4200 827 271.05 848 293.15 868 315.00 888 337.59 908 360.91 947 408.35 984 455.58 1021 504.90 1058 556.37
134772 4400 847 290.23 867 312.62 886 334.61 905 357.30 924 380.71 962 429.54 999 479.58 1035 530.47 1070 581.89
140898 4600 868 311.05 886 332.60 905 355.86 924 379.82 942 403.25 978 452.08 1014 503.44 1049 555.66 1083 608.40
147024 4800 889 332.53 907 355.41 925 378.85 943 402.89 960 426.25 995 476.20 1030 528.77 1064 582.19 1097 636.14
153150 5000 910 354.68 928 378.93 945 402.47 962 426.52 979 451.13 1013 502.17 1046 554.23 1079 608.64 1112 665.34
159276 5200 932 378.74 949 403.14 966 428.04 982 452.08 999 478.01 1032 530.19 1064 583.19 1096 638.59 1127 694.45
165402 5400 955 404.94 971 429.39 987 454.33 1003 479.71 1019 505.56 1051 558.82 1082 612.68 1113 668.85 1143 725.45
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
104142 3400 1061 510.49 1101 559.68
110268 3600 1067 533.34 1105 582.23 1143 633.42
116394 3800 1074 556.19 1111 606.56 1147 657.26 1183 710.07 1218 763.31
122520 4000 1083 581.06 1119 632.60 1154 684.73 1188 736.89 1223 792.85 1257 849.05 1290 905.39
128646 4200 1093 606.82 1128 659.41 1162 712.43 1195 765.75 1229 822.88 1261 877.82 1294 936.76 1326 995.58 1357 1054.21
134772 4400 1104 633.56 1138 687.22 1171 741.10 1204 797.06 1236 853.15 1268 911.20 1299 968.77 1330 1028.04
140898 4600 1116 661.34 1149 716.10 1182 772.83 1213 827.58 1244 884.21 1275 942.80 1306 1003.45 1336 1063.46
147024 4800 1130 692.09 1162 748.08 1193 803.88 1224 861.44 1254 918.67 1284 977.77 1314 1038.72 1343 1099.28
153150 5000 1143 720.48 1175 779.44 1205 836.15 1235 894.52 1265 954.61 1294 1014.16 1323 1075.52 1351 1136.14
159276 5200 1158 752.34 1188 810.20 1218 869.84 1248 931.24 1277 992.06 1305 1052.15 1333 1113.85
165402 5400 1173 784.08 1203 844.73 1232 905.15 1261 967.30 1289 1028.80 1317 1091.80 1344 1153.85
171528 5600 1189 817.88 1218 879.13 1246 940.09 1275 1005.11 1302 1067.11 1329 1130.63 1356 1195.59
177654 5800 1206 853.95 1234 915.71 1262 979.44 1289 1042.57 1316 1107.41 1343 1173.88
183780 6000 1223 890.41 1250 952.51 1277 1016.46 1304 1082.28 1330 1147.34 1356 1214.01
189906 6200 1241 929.60 1267 991.85 1294 1058.45 1320 1124.52 1345 1189.67
196032 6400 1260 971.74 1285 1034.12 1311 1100.84 1336 1166.91
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
Design 14 Design 17 Design 22 Design 26
735 890 1180 1360
19 Twin City Bulletin 400

Performance Data
Max. RPM
Design 14 Design 17 Design 22 Design 26
663 804 1041 1230
807 BCS Outlet Area: 37.49 ft 2 Wheel Diameter.: 80.75" Tip Speed (FPM): 21.14 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
44988 1200 227 9.24 288 18.05 342 27.94
48737 1300 236 10.36 293 19.41 345 29.73
52486 1400 245 11.53 299 20.90 349 31.64 395 43.28
56235 1500 254 12.76 306 22.57 354 33.74 398 45.66 440 58.62
59984 1600 264 14.19 313 24.24 359 35.76 402 48.21 443 61.73
63733 1700 274 15.71 321 26.16 366 38.32 407 51.03 446 64.64 483 78.91
67482 1800 285 17.51 330 28.38 372 40.52 412 53.77 450 67.81 486 82.53 521 98.13
71231 1900 295 19.23 338 30.40 379 43.02 418 56.81 455 71.34 490 86.44 524 102.45 556 118.57
74980 2000 306 21.25 347 32.76 387 45.87 424 59.78 460 74.77 494 90.21 527 106.55 559 123.57 590 141.22
82478 2200 329 25.91 367 38.33 403 51.73 438 66.47 472 82.35 504 98.52 535 115.36 565 132.84 594 150.84
89976 2400 352 31.15 387 44.33 421 58.67 453 73.64 485 90.19 516 107.61 545 124.97 574 143.48 602 162.45
97474 2600 375 37.01 408 51.23 440 66.42 470 82.05 500 99.12 529 117.03 557 135.52 585 155.15 611 174.25
104972 2800 399 43.88 430 59.14 459 74.62 488 91.37 516 108.84 544 127.73 571 147.26 597 167.17 622 187.25
112470 3000 423 51.54 452 67.76 480 84.37 507 101.72 534 120.22 559 138.58 585 158.94 610 179.72 635 201.62
119968 3200 447 60.04 475 77.59 501 94.85 527 113.24 552 132.09 576 151.26 601 172.41 624 193.05 648 215.72
127466 3400 472 69.88 498 88.26 523 106.69 547 125.38 571 145.20 594 165.21 617 186.22 640 208.40 662 230.73
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
89976 2400 629 181.81 656 202.23 682 222.76 707 243.38
97474 2600 637 194.41 662 214.73 687 236.13 712 258.48 736 280.72
104972 2800 647 208.28 671 229.33 695 251.38 718 273.36 741 296.32 787 344.87
112470 3000 658 222.58 682 245.45 705 268.21 727 290.74 749 314.19 792 362.60 834 412.91 875 465.13
119968 3200 671 238.45 693 261.03 715 284.44 737 308.72 758 332.61 800 383.05 840 434.18 880 488.40 918 542.39
127466 3400 684 254.07 706 278.40 727 302.46 748 327.34 769 353.05 809 404.19 848 457.12 885 510.07 923 567.63
134964 3600 699 271.88 720 296.76 740 321.32 761 348.07 780 372.88 819 426.11 857 480.91 893 535.40 929 593.01
142462 3800 715 291.10 734 315.12 754 341.32 774 368.47 793 395.05 830 448.91 867 505.64 902 561.75 937 620.75
149960 4000 731 310.72 750 336.26 769 362.75 788 390.15 806 416.91 843 474.38 878 531.40 912 589.18 946 649.68
157458 4200 748 332.15 767 359.24 785 385.88 803 413.44 821 441.85 856 499.49 890 558.29 924 619.83 956 679.83
164956 4400 766 355.53 784 382.82 801 409.48 818 436.97 836 466.96 870 526.18 903 586.61 935 647.74 967 711.36
172454 4600 784 379.59 801 407.00 818 435.18 835 464.21 852 494.13 884 552.90 917 616.67 948 679.23 979 744.34
179952 4800 803 405.85 820 434.95 836 463.19 852 492.11 868 521.81 900 583.65 931 646.69 962 712.65 992 779.06
187450 5000 823 434.51 839 463.75 854 491.92 870 522.47 885 551.91 916 614.90 946 679.00 976 746.03 1005 813.46
194948 5200 843 464.14 858 493.41 873 523.20 888 553.61 903 584.64 933 648.82 962 713.85 991 781.83 1019 850.16
202446 5400 863 494.85 878 525.73 893 557.26 907 587.47 922 620.20 950 683.49 978 749.30 1006 817.96 1033 886.89
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
127466 3400 959 624.41 995 684.23
134964 3600 964 651.48 999 712.63 1033 774.51
142462 3800 971 680.79 1004 741.47 1037 804.51 1070 870.28 1102 936.43
149960 4000 979 710.93 1011 772.77 1043 837.35 1074 901.81 1105 968.63 1136 1038.07 1166 1107.47
157458 4200 988 742.34 1019 805.19 1050 870.66 1081 938.89 1111 1006.90 1140 1074.34 1170 1146.94 1198 1216.14 1227 1290.89
164956 4400 998 775.18 1029 841.51 1059 907.91 1088 974.19 1117 1042.98 1146 1114.21 1174 1184.53 1202 1257.01 1230 1331.71
172454 4600 1009 809.54 1039 876.97 1068 944.27 1097 1013.88 1125 1083.17 1153 1154.85 1180 1225.88 1208 1302.14
179952 4800 1021 845.51 1050 914.15 1079 985.06 1106 1052.65 1134 1125.24 1161 1197.24 1188 1271.47 1214 1344.88
187450 5000 1034 883.41 1062 953.12 1090 1025.02 1117 1096.18 1144 1169.42 1170 1241.65 1196 1316.06 1222 1392.64
194948 5200 1047 920.97 1074 991.43 1101 1064.11 1128 1138.88 1154 1212.59 1180 1288.33 1205 1362.82 1230 1439.25
202446 5400 1061 960.99 1088 1034.94 1114 1108.29 1140 1183.71 1165 1257.96 1191 1337.33 1215 1411.88
209944 5600 1075 1001.06 1101 1075.40 1127 1152.08 1152 1227.88 1177 1305.64 1202 1385.40 1226 1463.55
217442 5800 1090 1044.17 1116 1121.78 1141 1198.84 1165 1274.81 1190 1356.14 1214 1436.05
224940 6000 1106 1090.62 1130 1165.38 1155 1245.59 1179 1324.81 1203 1406.17 1226 1485.99
232438 6200 1122 1137.76 1146 1215.55 1170 1295.76 1193 1374.87 1216 1456.03
239936 6400 1139 1188.76 1162 1266.41 1185 1346.36 1208 1428.58 1230 1509.40
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
20 Twin City Bulletin 400

Performance Data
Max. RPM
Design 14 Design 17 Design 22 Design 26
602 730 944 1116
890 BCS Outlet Area: 45.54 ft 2 Wheel Diameter.: 89" Tip Speed (FPM): 23.30 x RPM
CFM OV
1" SP
RPM BHP
2" SP
RPM BHP
3" SP
RPM BHP
4" SP
RPM BHP
5" SP
RPM BHP
6" SP
RPM BHP
7" SP
RPM BHP
8" SP
RPM BHP
9" SP
RPM BHP
54648 1200 206 11.23 261 21.84 311 34.17
59202 1300 214 12.56 266 23.62 313 36.11
63756 1400 222 13.95 272 25.59 317 38.56 359 52.85
68310 1500 230 15.40 278 27.53 321 40.91 361 55.42 400 71.63
72864 1600 239 17.13 284 29.45 326 43.55 365 58.69 402 75.02
77418 1700 249 19.18 291 31.69 332 46.52 369 61.85 405 78.73 439 96.36
81972 1800 258 21.13 299 34.33 338 49.43 374 65.41 408 82.20 441 100.29 473 119.42
86526 1900 268 23.45 307 37.05 344 52.32 379 68.88 412 86.14 444 104.60 475 124.12 505 144.50
91080 2000 278 25.92 315 39.86 351 55.67 385 72.79 417 90.60 448 109.43 478 129.31 507 149.95 535 171.25
100188 2200 298 31.31 333 46.57 366 63.03 397 80.50 428 99.86 457 119.46 485 139.78 513 161.72 539 183.29
109296 2400 319 37.71 351 53.79 382 71.28 411 89.45 440 109.52 468 130.58 495 152.29 521 174.50 546 197.12
118404 2600 340 44.87 370 62.14 399 80.56 427 100.07 454 120.68 480 142.19 506 165.24 530 187.65 555 212.41
127512 2800 362 53.29 390 71.77 417 91.01 443 111.17 468 132.07 493 154.62 518 178.81 541 202.34 565 228.26
136620 3000 384 62.71 410 82.25 435 102.14 460 123.57 484 145.59 508 169.16 531 193.33 554 218.97 576 244.74
145728 3200 406 73.17 431 94.27 455 115.56 478 137.43 501 160.62 523 184.16 545 209.11 567 235.56 588 262.14
154836 3400 428 84.74 452 107.34 474 129.18 496 152.04 518 176.32 539 200.76 560 226.46 581 253.58 601 280.79
CFM OV
10" SP
RPM BHP
11" SP
RPM BHP
12" SP
RPM BHP
13" SP
RPM BHP
14" SP
RPM BHP
16" SP
RPM BHP
18" SP
RPM BHP
20" SP
RPM BHP
22" SP
RPM BHP
109296 2400 571 221.21 595 245.42 619 270.89 642 296.39
118404 2600 578 236.22 601 261.32 624 287.78 646 313.98 668 341.36
127512 2800 587 252.98 609 278.85 631 305.98 652 332.93 673 361.06 714 418.83
136620 3000 597 270.37 619 298.48 639 324.82 660 353.81 680 382.39 719 441.25 757 502.21 794 565.24
145728 3200 609 289.95 629 317.45 649 345.97 669 375.55 688 404.50 725 463.70 762 527.15 798 592.33 833 659.09
154836 3400 621 309.23 641 338.89 660 368.07 679 398.23 697 427.55 734 490.97 769 554.44 803 619.69 837 688.44
163944 3600 634 329.95 653 360.07 672 391.37 690 421.98 708 453.55 743 517.46 777 582.93 810 649.86 843 720.65
173052 3800 648 352.44 666 382.87 684 414.43 702 447.12 719 478.91 753 545.20 786 612.75 819 683.91 850 753.70
182160 4000 663 377.05 681 409.42 698 441.20 715 474.04 732 507.94 765 576.58 797 646.47 828 717.12 858 788.34
191268 4200 679 404.08 695 434.69 712 468.30 728 501.06 745 536.96 776 605.23 808 679.45 838 751.99 868 827.61
200376 4400 695 431.89 711 464.40 727 497.93 743 532.59 758 566.12 789 638.34 819 711.81 849 788.73 878 866.00
209484 4600 712 462.42 727 494.92 742 528.28 758 564.81 773 600.19 802 671.53 832 749.11 860 824.77 888 903.45
218592 4800 729 493.90 744 528.39 759 563.75 773 597.76 788 635.00 816 707.51 845 786.42 872 863.25 900 946.23
227700 5000 747 528.45 761 562.85 775 597.95 789 633.83 803 670.53 831 746.71 858 823.92 885 904.61 912 988.69
236808 5200 765 564.14 779 600.62 792 635.40 806 673.30 819 709.45 846 786.74 873 867.69 899 949.30 924 1030.91
245916 5400 783 601.14 797 639.58 810 676.40 823 713.83 836 751.97 862 830.46 888 912.25 913 994.48 938 1079.98
CFM OV
24" SP
RPM BHP
26" SP
RPM BHP
28" SP
RPM BHP
30" SP
RPM BHP
32" SP
RPM BHP
34" SP
RPM BHP
36" SP
RPM BHP
38" SP
RPM BHP
40" SP
RPM BHP
154836 3400 870 758.22 903 831.82
163944 3600 875 792.37 906 864.52 937 940.09
173052 3800 881 827.01 911 900.87 941 977.68 971 1057.78 999 1134.60
182160 4000 888 862.86 917 937.84 946 1016.15 975 1097.34 1003 1178.14 1031 1262.09 1058 1345.60
191268 4200 896 900.53 925 979.54 953 1058.72 980 1137.77 1008 1223.09 1035 1307.62 1061 1391.10 1087 1477.49 1113 1567.03
200376 4400 906 943.27 933 1020.19 961 1103.43 987 1182.89 1014 1269.00 1040 1354.37 1065 1438.22 1091 1528.74 1116 1617.81
209484 4600 916 985.09 943 1066.39 969 1147.02 995 1230.46 1021 1316.87 1046 1402.34 1071 1490.74 1096 1581.66
218592 4800 927 1029.23 953 1111.66 979 1196.65 1004 1280.71 1029 1367.40 1053 1452.74 1078 1545.11 1102 1636.10
227700 5000 938 1072.61 964 1159.45 989 1245.32 1013 1329.80 1038 1420.72 1062 1510.26 1085 1598.08 1109 1692.92
236808 5200 950 1118.92 975 1206.46 999 1292.84 1024 1385.69 1047 1472.87 1071 1566.70 1094 1658.64 1116 1748.43
245916 5400 962 1165.05 987 1256.66 1011 1347.36 1034 1436.59 1057 1528.07 1080 1621.85 1103 1718.07
255024 5600 975 1214.75 999 1306.63 1022 1397.33 1046 1494.99 1068 1586.58 1091 1684.91 1113 1780.94
264132 5800 989 1268.55 1012 1360.53 1035 1455.29 1057 1548.54 1080 1648.74 1101 1742.30
273240 6000 1003 1322.96 1026 1418.79 1048 1513.37 1070 1610.66 1091 1705.92 1113 1808.34
282348 6200 1018 1382.11 1040 1477.59 1061 1571.64 1082 1668.28 1104 1772.19
291456 6400 1033 1442.33 1054 1537.11 1075 1634.87 1096 1735.36 1116 1833.58
Underlined figures indicate maximum static efficiency.
Performance is for BCS with outlet duct and with or without inlet duct.
BHP is a fan shaft brake horsepower and does not include belt drive losses.
21 Twin City Bulletin 400

Dimensional Data
AA
P
COUPLING GAP
143T – 405T = .13
444T – 445T = .19
ARRANGEMENT 8 PEDESTAL
HC HG
CW UBD
HA
DE
HA
C L
Fan
CW BHD
FRAME AA
SIZE ODP TEFC
143T-145T 14.50 14.50
182T-184T 14.75 16.38
213T-215T 17.38 20.38
254T-256T 22.63 25.88
284T-286T 25.50 29.00
324T-326T 28.63 32.13
364T-365T 29.88 34.50
404T-405T 34.38 41.38
444T-445T 40.19 49.19
HE HB
HG
DG
CW BAU
HF HG HP
22 Twin City Bulletin 400
HH
DC
DF
HE HA
G
CW DBD
HC
CW THD
ARRANGEMENT 1
NOTES:
1. CW rotation shown. CCW rotation similar but opposite.
2. Punched outlet flange is standard on all sizes.
3. Maximum dimensions are shown.
4. Dimensions are not to be used for construction. Certified drawings available upon request.
5. Please use the Twin City Fan Selector Program or contact your Twin City Fan & Blower sales representative for standard drawings
for fans in Arrangement 1 and Arrangement 9F.
HE
DA
HB
DD
P J
Outs
Hsg
H
A
Outs
Hsg
B
HD HH
CW TAU
SIZE A B C DA DC DD DE DF DG G
H
ARR. 1
HA
270 28.88 21.56 28.50 21.44 22.00 23.50 24.75 26.25 31.50 38.00 46.63 21.44
300 32.00 23.94 31.63 23.81 24.50 26.00 27.50 29.50 34.75 42.00 51.50 23.81
330 35.44 26.31 34.75 26.25 27.00 28.50 30.00 32.25 37.75 45.00 55.88 26.25
365 39.00 29.13 38.50 29.00 29.50 31.50 33.50 35.50 41.50 49.00 60.13 29.00
402 42.94 32.06 42.44 32.00 33.00 35.25 37.00 39.50 46.00 52.50 66.13 32.00
445 47.44 35.44 46.88 35.38 35.50 38.50 40.00 43.25 50.50 57.50 74.50 35.38
490 52.25 38.88 51.63 39.00 39.00 42.25 44.00 47.50 55.75 62.50 79.88 39.00
542 57.69 43.13 57.13 43.06 43.50 46.50 49.00 52.25 61.25 68.00 84.13 43.06
600 63.81 47.56 63.13 47.69 48.00 51.25 54.00 57.50 67.25 74.00 91.63 47.69
660 70.00 52.44 69.38 52.44 52.50 55.75 59.00 63.00 73.75 81.00 98.50 52.44
730 77.50 57.81 76.75 58.00 57.00 61.75 64.50 69.50 81.25 89.00 106.88 58.00
807 85.69 63.88 84.88 64.19 63.00 67.50 72.00 76.50 89.50 96.50 115.88 64.19
890 94.38 70.25 93.38 70.00 69.25 73.75 78.25 85.00 98.25 107.50 125.25 70.00
SIZE HB HC HD HE HF HG HH HP J
ARR. 1
P
ARR. 8
270 36.88 30.69 24.81 23.31 21.94 20.56 19.19 31.69 14.81 40.06 37.31
300 40.75 33.81 27.50 25.81 24.31 22.81 21.31 35.81 17.00 44.25 40.50
330 44.88 37.19 30.25 28.50 26.81 25.13 23.44 39.19 18.19 48.44 43.69
365 49.31 40.75 33.69 31.63 29.75 27.88 26.00 42.75 19.56 51.56 47.56
402 54.25 44.69 37.13 34.81 32.75 30.69 28.63 47.69 22.06 56.06 51.56
445 59.81 49.19 41.06 38.38 36.13 33.88 31.63 53.19 24.75 61.75 57.25
490 65.75 54.00 45.00 42.31 39.81 37.31 34.81 58.00 26.44 66.44 60.94
542 72.81 59.94 49.94 46.81 44.06 41.31 38.56 63.44 28.56 68.56 63.06
600 80.44 66.06 55.13 51.81 48.75 45.69 42.63 69.56 30.81 74.81 68.31
660 88.19 72.25 60.56 56.94 53.50 50.06 46.63 75.75 33.25 79.25 73.50
730 97.38 79.75 67.06 63.00 59.25 55.50 51.75 83.25 35.94 86.44 79.19
807 107.56 87.94 74.19 69.63 65.50 61.38 57.25 91.44 38.94 92.44 86.44
890 117.81 96.63 81.69 76.75 72.19 67.63 63.06 100.13 42.13 99.13 92.63
C
O.D.
Inlet

Typical Specifications
Fans shall be Type BCS, Backward Curved High Pressure Blowers, as manufactured by Twin City Fan & Blower,
Minneapolis, Minnesota.
Fans shall have a sharply rising pressure characteristic extending through the operating range and continuing to
rise beyond the efficiency peak to ensure quiet and stable operation. Fans shall have a non-overloading design
with self-limiting horsepower characteristics and shall reach a peak in the normal selection area.
PERFORMANCE — Fans shall be tested and rated in accordance with industry accepted test codes and shall
be guaranteed by the manufacturer to deliver rated published performance levels.
CONSTRUCTION — Fan housings and bearing pedestals shall be of heavy-gauge, continuously welded construction.
Housings with partially welded construction are not acceptable. Housings shall be suitably braced to prevent
vibration or pulsation. Discharge flanges shall be provided for rigidity and duct connection. Discharge flanges are
punched as standard. All units are furnished with lifting lugs.
WHEEL — BCS backward curved wheels shall be single thickness, designed for maximum efficiency and quiet
operation, and shall be continuously welded to the rim and back plate. Partial welding is not acceptable on
backward curved blades. All wheels shall be statically and dynamically balanced.
SHAFT — Shafts shall be AISI 1018, 1040 or 1045 hot rolled steel, accurately turned, ground, polished, and
ring gauged for accuracy. Shafts shall be sized for the first critical speed of at least 1.43 times the maximum
speed.
BEARINGS — Bearings shall be heavy duty, grease lubricated, anti-friction ball or roller, self-aligning, pillow block
type and selected for a minimum average bearing life (AFBMA L-50) in excess of 200,000 hours at the maximum
fan RPM.
DRIVE — Motor sheaves shall be cast iron, variable pitch on applications 20 HP and smaller, and fixed pitch
on 25 HP and larger. Drives and belts shall be located external to the fan casing and rated for 150% of the
required motor HP.
FINISH AND COATING — The entire fan assembly, excluding the shaft, shall be thoroughly degreased and
deburred before application of a rust-preventative primer. After the fan is completely assembled, a finish coat of
paint shall be applied to the entire assembly. The fan shaft shall be coated with a petroleum-based rust protectant.
Aluminum components shall be unpainted.
ACCESSORIES — When specified, accessories such as access doors, drains, inlet and outlet flanges, belt guards,
shaft and bearing guards, outlet screens, outlet dampers, inlet vanes, spark resistant construction, split housings,
high temperature construction, shaft seals, inlet boxes, and shaft coolers shall be provided by Twin City Fan &
Blower to maintain one-source responsibility.
FACTORY RUN TEST — All fans prior to shipment shall be completely assembled and test run as a unit at the
specified operating speed or maximum RPM allowed for the particular construction type. Each wheel shall be
statically and dynamically balanced in accordance with ANSI/AMCA 204-96 “Balance Quality and Vibration Levels
for Fans” to Fan Application Category BV-3, Balance Quality Grade G6.3. Balance readings shall be taken by
electronic type equipment in the axial, vertical, and horizontal directions on each of the bearings. Records shall
be maintained and a written copy shall be available upon request.
GUARANTEE — The manufacturer shall guarantee the workmanship and materials for at least one (1) year from
startup or eighteen (18) months from shipment, whichever occurs first.
23 Twin City Bulletin 400

A Twin City Fan Company
1MWG12/10
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5959 Trenton lane n | minneapolis, mn 55442 | Phone: 763-551-7600 | fax: 763-551-7601