2000 Hook-up Book - Spirax Sarco

SYSTEM DESIGN
54
Clean Steam
Figure 59
Effective Condensate Drainage
Process/
Medium
Process
Trap
Drip
Trap
Steam
Inlet
A hospital was experiencing continuing problems with a
number of its sterilizers which were having an adverse
effect on both the sterilization process itself and the
amount of maintenance required to keep the units in service.
These problems included:
• Ineffective sterilization
• Prolonged sterilization cycles
• Wet and discolored packs
• Instrument stains, spotting and rusting
• High maintenance of drain traps and controls
• Dirty sterilizer chambers requiring frequent cleaning
Solution
In discussion with the hospital maintenance engineer, the
Spirax Sarco Sales Representative offered the opinion
that these problems were a result of a wet and contaminated
steam supply. In a number of cases the steam
supply to the sterilizers was unconditioned, allowing moisture
and solid particles, such as pipe scale and rust, to
enter both the sterilizer jacket and chamber, resulting in the
problems identified by the user.
The solution was to install Spirax Sarco steam filter
stations. Each steam filter station is comprised of:
• An isolation valve to aid in maintenance.
• A separator complete with strainer and drain trap to
remove residual condensate and any entrained moisture
being carried in suspension within the steam.
• A main line strainer to remove larger solid particles.
• A steam filter and drain trap combination.
Table 15: Saturated Steam Capacities — OD Tube Capacities in lb/h
Tube Size (O.D. x 0.065 inch wall)
Pressure Velocity
psi ft/sec 1 /4" 3 /8" 1 /2" 3 /4" 1 1 1 /2" 2" 1 2 /2" 3"
50 — — 5 20 35 90 170 270 395
5 80 — 5 10 30 60 145 270 430 635
120 — 5 15 45 85 215 405 650 950
50 — 5 10 25 45 110 210 335 490
10 80 — 5 15 35 70 180 330 535 785
120 — 10 20 55 110 270 500 800 1175
50 — 5 10 30 60 155 285 460 675
20 80 — 10 20 50 100 245 460 735 1080
120 5 10 25 75 150 370 685 1105 1620
50 — 5 15 40 80 195 365 585 855
30 80 5 10 30 65 125 310 580 935 1370
120 5 15 35 95 190 465 870 1400 2050
50 — 10 15 50 95 235 440 705 1035
40 80 5 10 25 75 150 375 700 1125 1655
120 5 20 40 115 230 556 1050 1690 2480
50 — 10 20 55 110 275 515 825 1210
50 80 5 15 30 90 180 440 820 1320 1935
120 5 20 50 135 265 660 1235 1980 2905
50 — 10 25 65 125 315 590 945 1385
60 80 5 15 35 105 205 505 940 1510 2215
120 5 25 55 155 305 755 1411 2265 3325
50 5 15 30 80 160 395 735 1180 1730
80 80 5 20 45 130 255 630 1175 1890 2770
120 5 30 70 195 380 950 1764 2835 4155
50 5 15 35 95 190 470 880 1415 2075
100 80 5 25 55 155 305 755 1410 2265 3320
120 10 35 85 230 455 1135 2115 3395 4975
50 5 20 40 115 220 550 1030 1650 2420
120 80 5 30 65 180 355 885 1645 2640 3875
120 10 40 95 270 535 1325 2465 3965 5810
Case in Action: Hospital Sterilizer
The steam filter specified was a Spirax Sarco CSF16
fitted with a 1 micron absolute filter element. The cleanable
CSF16 filter element ensured that 99% of all particles larger
than 0.1 microns were removed, while the thermostatic
steam trap drained any condensate that formed in the filter
body during operation and periods when the steam supply
to the sterilizer was isolated. These installations resulted in
steam supplies free of both moisture and solid particles.
Benefits
• Effective sterilization every time
• Reduced sterilization cycles and improved productivity
• High quality of packs and instruments without spots,
stains or corrosion
• Minimal re-work of sterilizer loads
• Reduced cleaning and maintenance of sterilizer, drain
traps and controls
Cost Savings
With the help of the hospital maintenance engineer, a
steam filter station payback analysis sheet was completed.
The estimated cost of maintenance, the cost associated
with re-working wet or spotted packs, and the cost due to
loss of performance were included in the payback calculation.
In total, annual costs were over $25,000 for each
sterilizer. Using this figure a payback period of less than
two months was established for suitably sized Spirax Sarco
steam filter stations.