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 (c) Ensure that all installation, repair, and cleanup work is
completed. T h i s includes cleaning and flushing the piping system.
(d) Make sure that conduits and passages are free from obstructions and
are tight.
( e ) Make sure insulat i o n is correctly installed, dry, and in good
condition.
( f ) M a k e s u r e a l l a u x i l i a r y equipment is correctly installed and ready
f o r operation.
2 SYSTEM STARTUP. B e f o r e starting up the system notify the steam generating
station and the steam consumers. P r e p a r e a starting schedule and supply it to
a l l interested parties so that adequate provisions may be made. For new
d i r e c t buried conduit and concrete shallow trench systems ensure that
p r o c e d u r e included in the system supplier's product brochure are followed.
2 . 1 Startup Procedure. S t a r t u p of steam distribution lines which lead to
f a c i l i t i e s and processing areas should be done in a slow, bleed-type manner,
e s p e c i a l l y where lines have been shut down for only a short period of time.
The high-pressure, h o t steam mixing with residual low-pressure, cold
c o n d e n s a t e can cause violent reactions which may result in burst joints and
d a m a g e d piping, fittings, and metering devices. Where bypass lines have been
i n s t a l l e d at valve stations, the valve should be left closed and the bypass
l i n e opened during startup. Once pressure has equalized on both sides of the
valve," then open the valve and close the bypass line. T h i s a c t i o n w i l l
prevent possible warpage damage to the valve. C o n t i n u e with the following
procedure.
vents.
(a) Open all manual
( b ) Place steam traps in service by opening the isolating valves. Trap
bypass valves, when provided, may be opened during startup to speed up the
discharge of air and condensate. They must be closed, however, when the
s y s t e m is in normal operation.
( c ) Before placing the steam lines in service, warm up the piping slowly
by passing a small amount of steam. V a l v e s 8 inches in size and larger are
If no bypass
u s u a l l y provided with a small bypass valve for this purpose.
v a l v e s are available, crack open the required main valves. To bring a cold
steam line to operating temperature, a considerable amount of steam must be
condensed. The amount depends on the size of the line and the time required
3-14
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