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 Simplified pressure reduction at buildings
Substitution of standard cast iron fittings
Less maintenance
3 . 2 High-Pressure Steam. High-pressure steam, above 15 psig, is used for
i n d u s t r i a l purposes, process work, hospital uses, laundry machinery, and dry
c l e a n i n g . F o r extensive outside distribution, high-pressure steam at or above
100 psig is commonly employed. F i g u r e 3-1 illustrates a schematic flow
d i a g r a m of a steam distribution system. In this system, steam is generated at
1 0 0 psig in a central steam generating station and then distributed to
consumers. The diagram shows conversion of high-pressure 100-psig steam to
4 0 - p s i g low-pressure steam for hospital uses. R e d u c t i o n to 5-psig steam for
space heating purposes is also shown. Steam for laundry machinery, however,
is used at 100-psig pressure. System components such as valves, traps,
pressure reducing valves, pumps, and other required equipment are considered
The main advantages of high-pressure steam vice low
i n following chapters.
p r e s s u r e steam distribution are:
S m a l l e r pipe sizes
A v a i l a b i l i t y for purposes other than heating
M o r e flexibility in design for velocity and pressure drops
4 DISTRIBUTION ROUTE. T h e piping route for steam distribution systems is
s e l e c t e d to obtain the minimum possible distance from the central generating
station to the demand centers. T h e following factors affect selection of the
route (for additional factors refer to NAVFAC DM-3, Design Manual, Mechanical
Engineering):
Characteristic of the location
Future growth
B a s e m e n t s or crawl spaces available for piping
E x i s t i n g tunnels or trenches available for the system
A b o v e g r o u n d obstructions, such as rivers or roads
U n d e r g r o u n d obstructions, such as piping or rock
Soil Corrosivity
3-2
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