Coltri pressure maintaining valve, does it work properly?

[Agro]

Coltri Pressure Maintaining valve Silver | Diveinn I exchanged all the o-rings on this PMV, now it works more or less.

Compressor produces 0 to 150 bar, PMV has a very small blow-by, nearly zero.
Compressor produces 150+ bar, filling hose has the same pressure.
When I stop compressor, we still have this small blow by. Within 10 min compressor has nearly zero bar.

I do not know if this is correct. I expected a hysteresis of perhaps 50 bar, compressor pressure goes down from 150 bar to 100 bar, then PMV closes compeltely.

Does anyone use this Coltri PMV and can tell me if this heaviour is normal? Thanks.

 

[Agro]

Nobody has experience with Coltri's PMV?

 

[Agro]

Nobody?

 

[JackZwykle]

Coltri Pressure Maintaining valve Silver | Diveinn I exchanged all the o-rings on this PMV, now it works more or less.

Compressor produces 0 to 150 bar, PMV has a very small blow-by, nearly zero.
Compressor produces 150+ bar, filling hose has the same pressure.
When I stop compressor, we still have this small blow by. Within 10 min compressor has nearly zero bar.

I do not know if this is correct. I expected a hysteresis of perhaps 50 bar, compressor pressure goes down from 150 bar to 100 bar, then PMV closes compeltely.

Does anyone use this Coltri PMV and can tell me if this heaviour is normal? Thanks.

Mine doesn't leak so fast, but it does leak a bit. I can't see how it can be worrying.
The main point is keeping the backpressure in the filters at ca 150 bar, which both mine and yours do.
When the compressor is stopped you need to bleed all the pressure and dump the condensate anyway, so I can't see how keeping the backpressure is relevant to anything then.

 

[grantmac]

The Bauer PMV will hold pressure in the filter stack for weeks. In my mind I want that stack undergoing as few cycles as possible both for a metal fatigue and also keeping the filter from receiving gas which hasn't been dried by the condensers.
The last part can impact filter life which is already very poor on the little coltri units

 

[JackZwykle]

The Bauer PMV will hold pressure in the filter stack for weeks. In my mind I want that stack undergoing as few cycles as possible both for a metal fatigue and also keeping the filter from receiving gas which hasn't been dried by the condensers.
The last part can impact filter life which is already very poor on the little coltri units

Just for me to understand, you're saying it's a good idea to:

1. Keep the insides of the compressor soaking in the moisture from the condenser that will start dispersing instead of dumping it.
2. Starting the compressor pressurised, with all the extra load during startup.
3. Compare a Coltri to a Bauer?

 

[grantmac]

The Bauer has a series of 1 way valves which permits you to depressurize the compressor without draining the filter stack. Keeping it under pressure is absolutely advised for the reasons I stated.
But of course coltri wouldn't bother with that.

 

[Agro]

The Bauer has a series of 1 way valves which permits you to depressurize the compressor without draining the filter stack. Keeping it under pressure is absolutely advised for the reasons I stated.
But of course coltri wouldn't bother with that.

I fully agree.

 

[AKinnunen]

At least in the old MCH-6 compressor filter tower, the design does not support PMV use. The pressure goes past the O-ring. A slightly larger O-ring might help. I replaced the filter tower; after that, it works well. Looks that Coltri's filter tower tolerances are varible becase all users does not have same problem.

 

[Wookie]

Mine doesn't leak so fast, but it does leak a bit. I can't see how it can be worrying.
The main point is keeping the backpressure in the filters at ca 150 bar, which both mine and yours do.
When the compressor is stopped you need to bleed all the pressure and dump the condensate anyway, so I can't see how keeping the backpressure is relevant to anything then.

You might dump the condensate from the final separator, but I hope you aren't draining the filter tower. Otherwise why have a PMV?