monitoring for various needs the entire year, the shutdown of a complete
s y s t e m is impractical. H o w e v e r , there is usually the possibility to shut down
s e c t i o n s or individual lines of the system. When a shutdown involves
i n d i v i d u a l f a c i l i t i e s , i t is necessary to shut down the distribution piping to
t h e f a c i l i t y , n o t j u s t t h e f a c i l i t y , i f there is to be any significant energy
an energy loss of considerable measure.
4.1 Shutdown Procedure. Before shutting down the system, notify the steam
generating station and the steam consumers. T h e n continue with the following
( a ) Slowly close main valves.
(b) Crack open manual vent val v e s to relieve the pressure. The time
required to bring down the pressure d e p e n d s on the amount of throttling of the
v e n t valves.
( c ) Check operation of steam traps. When the system steam pressure is
t o o low for proper operation of the traps, open the bypass valves for direct
drainage of the condensate.
Keep drai n and vent valves wide open to ensure the lines drain
(e) Keep drai n i n g equipment in service to eliminate any water resulting
f r o m i n f i l t r a t i o n in underground systems.
4 . 2 Shutdown of Piping.
Long lines which have been encased in a Gilsonite type moisture
b a r r i e r should be given consideration before shutdown. Shutdown
p r e s e n t s the possibility of cracking the barrier when the line
W h e r e modifications have been made to the original configuration of
the system or where metering and other devices protrude from the
p i p i n g , shutdown may not be possible. Inspect entire line to
e n s u r e that, especially where clearances are minimal, contraction
w i l l not cause bending, damage, or breakage to piping and
Shutdown of steam distribution piping does not require any unusual methods.
A f t e r selecting the line to be shut down, c l o s e the valving to prevent steam
f r o m entering the line. A l l o w t h e l i n e t o c o o l , t h e n o p e n a l l d r a i n f i t t i n g s
R e p a i r or replace all valves,
i n the line to rid the line of condensate.
t r a p s , s t r a i n e r s , a n d other fittings that are known to be in need of