Boiler Safety Valve Ppt

Boiler Safety Valves

62b-206 

Definitions  Lift or pop  -- refers to the opening of the safety valve  BLOWDOWN  - the pressure drop between lift and reseating of the safety valve  Reseat  - losing of the safety valve without hattering  

Definitions Cont  !i""ering - stea" that lea#s by the seat and dis# prior to the lifting of the safety valve$ %eptable  ondition ondition within &' of lifting pressure$

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(hattering  - the rapid popping and reseating of the safety valve$

Definitions Cont )ag - a "ehanial devie plaed on the safety to prevent the safety  fro" lifting during testing and boiler hydrostati tests

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Required Testing  *%W +,! 

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When re"oved or rewor#ed 

 %fter being gagged for hydro

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 *f lifted by water during hydro when not gagged 

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 %ny signs of ta"pering 

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Testing: How It’s Done  Light off the boiler 

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 +lae gags on top of boiler to war" and epand 

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 +lae the boiler online  with with e.uip"ent neessary to support setting safeties

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ONLINE MAIN STEAM

CO!O" #$R 

STOP OPEN

BOILR  LOCKED

AUX STEAM STOP OPEN

OPEN

Testing: CO!’T  /nsure boiler water he"istry is within standards

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When stea" pressure &00 -200 +!* below lowest safety valve plae gags on safeties$ /eptions1 do not gag highest dru" safety

Testing : CO!’T 3est4set highest set dru" valve$  Re"ove gag net lower set valve and test4set$  Re"ove gag fro" !5+/R/%3/R safety test4set !5+/R/%3/R safety$  One pilot 7%7L/ set8 test pilot  !5+/R/%3/R o"bo$ 

#LOC’S  and easing gear - he# leanliness8 lubriation8 ables pulleys and  gearboes free to "ove

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9or# lever - he# learane usually &4&6: set *%W "anufatures tehnial "anual 

#LOC’S

 Lo#s  and and seals  -- he# for signs of ta"pering 

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7isual 

Boiler Safety Valves

62b-206