62B-206 Boiler Safety ValvesDefinitions
Lift or pop - refers to the opening of the safety valve
BLOWDOWN - the pressure drop between lift and reseating of the safety valve
Reseat - closing of the safety valve without chattering
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Definitions Cont
Simmering - steam that leaks by the seat and disk prior to the lifting of the safety valve. Acceptable condition within 1% of lifting pressure.
Chattering - the rapid popping and reseating of the safety valve.
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Definitions Cont
Gag - a mechanical device placed on the safety to prevent the safety from lifting during testing and boiler hydrostatic tests
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If lifted by water during hydro when not gagged
Any signs of tampering
Light off the boiler
Place gags on top of boiler to warm and expand
Place the boiler online with equipment necessary to support setting safeties
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Ensure boiler water chemistry is within standards
When steam pressure 100 -200 PSI below lowest safety valve place gags on safeties. (Exceptions: do not gag highest drum safety)
62B-206-* 15 JAN 99
Remove gag next lower set valve and test/set.
Remove gag from SUPERHEATER safety test/set SUPERHEATER safety.
Once pilot VAVLE set, test pilot SUPHERHEATER combo.
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Hand easing gear - check cleanliness, lubrication, cables pulleys and gearboxes free to move
Fork lever - check clearance usually 1/16” set IAW manufactures technical manual
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Visual
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