Coltri PMV doesn't work

[AKinnunen]

The inside diameter of the filter tower is too large and the O-ring does not seal. The quick and dirty solution can be a bigger O-ring.
I made a new tower with the correct dimensions, it works perfectly. I believe that because PMV is a new feature of Coltri old filter towers' tolerances don't support it (this is my personal guess)
Some information is here:
MCH-6 restoration project

My Metal Workshop

CCR manual valve project This is a small project since there's not much to do recently, waiting for COVID to end so we can travel again... I serviced my CCR manual valves (MV) and found that it had leaked water inside. After further investigation, the leak was due to low tolerances, wrong...

scubaboard.com

Arto

 

[Aliparker]

Not happy at all.
Not only does the PMV not seal on the bottom o ring.
Neither dose the filter that comes with it when used with the sealing plug. Works well with the filter under the PMV but the PMV still won’t work.
The screw thread diameter has been drill 15-20mm too deep. It should have stopped at the bottom of the outlet hole.
I been pumping unfiltered air for 2 years. Only 33hrs on the unit but still not good.
Air did have a bit of a smell but not too bad
I really hope Coltri will resolve this

 

[iain/hsm]

Just to add to your problems when you fit the new PMV on an old MCH-6 you need also to replace the charging connector (A clamp or DIN ) with a new charging connector that incorporates a bleed valve.
(about £40- £50 )

I'm surprised the shop you bought it from didn't advise you on this. Further you may also consider the need to add another £50 to your already £50 spent for a pressure gauge to fit to the new charging connector and bleed.

Now if you don't what the gauge all you have to do is rely blind on the pressure switch to switch off when full (if fitted) or when your cylinder is overfilled the relief valve will open blasting the grit and dust off the floor when you're a tad over full.

But look on the bright side. You can always claim its Coltri's British equivalent of a "Cave Fill".

And if nothing else the principle reason why you should never buy breathing air components off some scoobe doo web site or for that matter any HP compressor company that sells also to air gunners and paintballers (or Coltri it would seem. )

 

[Aliparker]

Just to add to your problems when you fit the new PMV on an old MCH-6 you need also to replace the charging connector (A clamp or DIN ) with a new charging connector that incorporates a bleed valve.
(about £40- £50 )

I'm surprised the shop you bought it from didn't advise you on this. Further you may also consider the need to add another £50 to your already £50 spent for a pressure gauge to fit to the new charging connector and bleed.

Now if you don't what the gauge all you have to do is rely blind on the pressure switch to switch off when full (if fitted) or when your cylinder is overfilled the relief valve will open blasting the grit and dust off the floor when you're a tad over full.

But look on the bright side. You can always claim its Coltri's British equivalent of a "Cave Fill".

And if nothing else the principle reason why you should never buy breathing air components off some scoobe doo web site or for that matter any HP compressor company that sells also to air gunners and paintballers (or Coltri it would seem. )

Already sorted the bleed on the whip.
The compressor pumps to 300bar din, but I have a 300- 232 converter with blow off so no need for the guage.
Having the compressor will still beat the couple of hrs, going to get a fill.

 

[iain/hsm]

but I have a 300- 232 converter with blow off so no need for the guage.

I still would suggest with a PMV or BPR you would still be better off using a pressure gauge
I would go so far as to say a pressure gauge is essential.

Although a relief valve should lift at some point ( if its not stuck) the risk you take is not knowing what the relief pressure it is set to or its hysteresis lift range.

A modern high pressure compressor designer would set the relief pressure around 15% to 20% above the nominal filling pressure. It can be a full release as per PED directive of a pressure relieving type as used in
say a commercial diving application so as to avoid killing the diver if and when the relief valve opens.

The idea in general with breathing air compressors is that the pressure switch (if fitted) is used as the auto stop and is set set to the maximum working pressure. 200 232 300 bar etc

In the event the pressure switch breaks or gets stuck the second line of defence is the motors overload relay set to cut out as the amps increase.

The relief valve is the 3rd line of defence set to 15% to 20% ) above this.
Frankly It's a safety device not a form of control. Iain