Sizing criteria for reciprocating compressor piping 1

[compo]

Does anyone have specific guidelines or references for maximum velocities that should be used when sizing the process piping on recip's. I have a very non specific reference that states the piping should be sized for a maximum velocity of 12m/s.

thanks

 

[1969grad]

I size the suction and discharge lines for a max velocity equal to the erosion velocity specified in API 14E with a factor of 100.

I then check the unit pressure loss and adjust the line size to get 0.25 to 0.5 psi/100 LF.

The above procedure most likely will give you a velocity higher than 12 m/s. Don't know any justification for this low a velocity unless your pulsation analysis warrants it to limit the forces in elbows, etc. although I have never experienced this problem following the above.

Another approach is to size the piping pressure loss to be equal to the allowable peak-to-peak pulsation pressure.

If noise is a problem then insulate the piping.

By the way, the bypass line size is typically half the suction line size.

 

[Hookem]

robk1:

Consider API 14E which limits velocities to 60 feet per second - for noise control.

Consider too, limiting pressure drop in suction piping to 1/4 psi per 100 feet, and in discharge piping to 1/2 psi per 100 feet.

 

[pmover]

not only does velocity need to be considered, but the pulsations generated need to be considered as well. if you are referring to the piping upstream/downsteam of pulsation control devices, then the previous responses should suffice.
it is best to have a pulsation study/analysis accomplished during the design in which the entire system design (i.e. compressor details + piping arrangement, etc.) are addressed.
-pmover

 

[PAN]

For the max. velocity criteria of 12 m/s. It depends on sonic velocity and molecular weight of gas.