Blowdown for compressor restart
Blowdown for compressor restart
(OP)
Hello All ,
I have question regarding the reciprocating compressor restart upon shutdown .
Upto how much pressure should I blowdown the package so that the compressor can be re-started without any problem .
Blow down is preffered over settle out ........
Thx !
I have question regarding the reciprocating compressor restart upon shutdown .
Upto how much pressure should I blowdown the package so that the compressor can be re-started without any problem .
Blow down is preffered over settle out ........
Thx !





RE: Blowdown for compressor restart
RE: Blowdown for compressor restart
RE: Blowdown for compressor restart
RE: Blowdown for compressor restart
RE: Blowdown for compressor restart
RE: Blowdown for compressor restart
In all cases, the entire train is blocked in for the shutdown and blowdown sequence, which always includes all inventories from the suction SDV right up to the final discharge SDV.
RE: Blowdown for compressor restart
The key aspect is the seal arrangement and ensuring that all components are suitably rated for the pressure which could easily equalize between the inlet and outlet valves.
Each system will be different so the first point of call is the compressor vendor to find out what the impact is of certain pressures in the compressor when it is not moving.
After that it is a systematic examination of the system to see what is the potential impact on other bits of plant.
Legislative requirements and company procedures may not permit this, but they are location and client dependant.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Blowdown for compressor restart
RE: Blowdown for compressor restart
It's not a bomb if it stays in the pipe and doesn't over pressure it.
Agree that operators sometimes find ways to defeat certain annoying features of a design, but equally venting gas each time you stop or trip is a waste of gas and delays re-start. That's the balance that good design brings.
The OP is asking a question no one can answer without the specific details, but is talking about a recip compressor so IMHO it will revolve around what the vendor is happy with for his particular machine.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Blowdown for compressor restart
The regulations requiring blowdown refer to station ESD, as opposed to momentary operational shut downs.
RE: Blowdown for compressor restart
RE: Blowdown for compressor restart
I'd contact your compressor manufacturer and provide them with the model and serial number.
They should be able to provide you with a better answer as they know how they fabricated your specific unit.
Regards
Gabriel Castaneda, P.E.
http://www.gabcheminc.com
RE: Blowdown for compressor restart
(1) It <ESD system> must be able to block gas out of the station and blow down the station piping.
"Blow down" means 0 differential pressure remamining between station piping, equipment and atomospheric pressure.
I'd be happy to ask for confirmation of that definition from PHMSA, if you'd like me to.
RE: Blowdown for compressor restart
Bottom line is that figuring out the maximum allowable startup pressure is most commonly a trial and error process. Some calculations can be made to predict the pressure, but most of the time, either the engineering know how to do so, or a knowledge of the required detail of the package does not exist, thus one must resort to trial and error.
Will