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 Section 2.
STEAM DISTRIBUTION METHODS
1 TYPES OF DISTRIBUTION SYSTEMS. Two main systems are used for distribution
of steam: a b o v e g r o u n d distribution systems and underground distribution
The decision to select an aboveground system or an underground
systems.
system depends on the following factors:
Permanent against temporary use
H i g h water table ground conditions
Degree of hazard (as when the overhead piping may cause a potential
d a n g e r to aircraft or other operations)
2 ABOVEGROUND DISTRIBUTION SYSTEMS. A b o v e g r o u n d distribution systems shall
b e selected whenever practical. Due to their ease in detecting when and where
m a i n t e n a n c e is required, N A V F A C prefers this type of installation. With
proper maintenance, t h i s type of system is the most energy efficient and cost
effective.
2.1 Advantages of Aboveground Systems. The main advantages of using
aboveground vice underground distribution systems are:
Lower initial cost
Less maintenance
E a s y detection of failure
H i g h e r continuous operating efficiency
L o n g e r life
Reduced external corrosion
2 . 2 D i s t r i b u t i o n L i n e s . D i s t r i b u t i o n lines usually consist of aboveground
c o n d u i t s supported as follows:
Low Elevations. For aboveground systems installed at low
e l e v a t i o n s , the conduits are supported on concrete pedestals, steel
frames, or treated wood frames. Supports are spaced 10 to 15 feet on
centers depending on pipe size.
H i g h Elevations. At higher elevations aboveground, conduits may be
supported on wood, steel pipe, H - s e c t i o n steel poles with crossarms,
o r steel frameworks fitted with rollers and insulation protection
saddles.
Long Spans. When long spans are required, conduits are supported
by cable suspension with supports up to 50 feet on center.
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