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HP BY PASS WARM UP. METHODS: (A) Equalising line with orifice (B) Drain line at upstream side of valve connected to downstream side of Main Steam line strainers. Method (A):
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HP BY PASS WARM UP METHODS: (A) Equalising line with orifice (B) Drain line at upstream side of valve connected to downstream side of Main Steam line strainers
Method (A): This method results in certain amount of loss of heat energy and increases HP By Pass downstream temperature and some times causes problems in proving emergency operation of HP By Pass. Method (B): This method is suitable for short HP By Pass upstream line
SUGGESTIONS • To effectively warm up Main Steam line it is preferable to take tap off for HP By Pass near to strainer or after the strainer similar to LP By Pass • The lines are to be taken to the higher elevation . The horizontal portion of the line to be kept as minimum as possible to prevent condensate collection in the upstream side of HP By Pass
SUGGESTIONSContd…. • It is preferable to have a drain pot at the downstream side of individual Hp By Pass with provision to drain condensate through level switches • Water collection in the downstream side orifice plate is expected at Simhadri since the orifice dia. is more than the pipe size.Such deviations are to be prevented
60.3 *12.5 (STUB AT BOTTOM OF THE PIPE) FE TE HP BP VAV 200 MM TO MAIN STEAM STRAINER DOWN STREAM Nb 50 LINE DIRT TRAP MSL LOCK OPEN CRH HP BYPASS WARMUP SCHEME -1
60.3 *12.5 (STUB AT BOTTOM OF THE PIPE) FE TE HP BP VAV 200 MM Nb 50 LINE MSL LOCK OPEN CRH TO TURBINE FLASH TANK 10M min. HP BYPASS WARMUP SCHEME -2