Controls & Instrumentation Product Manual - Spirax Sarco

Designing of Steam Tracing
Recommended number of 1/2" tracers to meet average requirements
Type A Type B Type C
General frost Where solidi- When solidificaprotection
or fication may tion may occur
where solidi- occur at temps. at temps.
fication may between 75 - between 150 -
occur at temps. 150˚F 300˚F
below 75˚F
Product Number of Number of Number of
Line Size 1/2" Tracers 1/2" Tracers 1/2" Tracers
1" 1 1 1
1-1/2" 1 1 2
2" 1 1 2
3" 1 1 3
4" 1 2 3
6" 2 2 3
8" 2 2 3
10"-12" 2 3 6
14"-16" 2 3 8
18"-20" 2 3 10
As a general rule, length of tracers to 3/8" size should not exceed 60 ft. Larger
size tracers should not exceed 150 ft. in length.
Pressure Drop psi/100 ft
15.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
.9
.8
.7
.6
.5
.4
.3
.2
.1
100
Steam Tracing
Steam Pipe Sizing
Sizing for Pressure Drop per 100 ft. in Schedule 40 Pipe
Divide “Allowable Drop" by pressure factor and use chart to select pipe size.
Based on 100 psig saturated steam
For other pressures, multiply chart ∆P by factor below
Steam Flow lbs/h
Steam Size Connections for Jacketed Lines
Product Line Jacket Diameter
Steam
Connection
2-1/2" 4" 1/2"
3" 6" 3/4"
4" 6" 3/4"
6" 8" 3/4"
8" 10" 1"
10" 12" 1"
Length of jacket should not exceed 20 ft. In most cases 1/2" condensate outlet
would be adequate but it is usual to make this same size as the steam connection
as it simplifies installation.
Recommended Header Size
for Supplying Steam Tracer Lines
Header Size Number of 1/2" Tracers
3/4" 2
1" 3 to 5
1-1/2" 6 to 15
2" 16 to 30
Recommended Header Size
for Condensate Lines
Header Size Number of 1/2" Tracers
1" Up to 5
1-1/2" 6 to 10
2" 11 to 25
psig 0 2 5 10 15 20 30 40 60 75 90 100 110 125 150 175 200 225 250 300
factor 6.9 6.0 5.2 4.3 3.6 3.1 2.4 2.0 1.5 1.3 1.1 1.0 0.92 0.83 0.70 0.62 0.55 0.49 0.45 0.38
1/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 5" 7" 8" 10" 12" 14" 16" 18" 20"
200 300 400 500 1,000 2 3 4 5 10,000 2 3 4 5 6 7 8 100,000 2 3 4 5 1,000,000 2
Spirax Sarco, Inc., 1150 Northpoint Blvd., Blythewood, SC 29016 • Phone: (803) 714-2000 • Fax: (803) 714-2222
350 400 500 600
0.33 0.29 0.23 0.19
24"
Engineering
Data
303