halls 2118 screw

[malvern]

I have a Halls 2118 screw compressor with an oil vent to suction. Discharge gas / oil is constantly returning to the suction, there are no regulating / solenoid valves in this line only a 5/8 ball valve . The suction temp gets up to 40 deg c. I suspect this vent valve is to relieve oil from the slide to allow the screw to unload? and maybe a seal is passing. has any boby came accross this before

[Dimitris]

Hi Malvern, check if the unloader works properly. If it doesn't, you've probably got leakage from the slide assembly, through the seal.

[malvern]

Hi dimitris thanks for the help.I have checked the compressor for loading / unloading and it works fine.This is an old system which i have just taken over the maintenance on I suspect it may have been operating like this for some time.

[Andy]

I have a Halls 2118 screw compressor with an oil vent to suction. Discharge gas / oil is constantly returning to the suction, there are no regulating / solenoid valves in this line only a 5/8 ball valve . The suction temp gets up to 40 deg c. I suspect this vent valve is to relieve oil from the slide to allow the screw to unload? and maybe a seal is passing. has any boby came accross this before

Er 40 deg c suction, pull the side covers off and have a look in that can't be right

Anything coming from the discharge side wouldn't be an old return from the slide cylinder, does this happen at any particular slide loading percentage???

sounds line a balance line to stop gas pulsations at low side position, if so the slide will cover this port after the compressor loads up to an sort of decent capacity percentage.

Let me know how it goes, I might have a look at the halls manual if yoy can give me an idea where the pipe connects.

Kind Regards. Andy