Help please! OPV on Bauer JrII not opening...

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teneicm

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Hello! We recently serviced our 8 year old Bauer Jr. II after not having run it for about a year. Changed the oil, changed the air filter, tightened the belt (ours is electric). Started right up and everything was fine until I noticed the OPV (over pressure valve) wasn't opening at 3200 psi. Pressure increased up to about 4000 before I bled off the excess and and shut the unit down. Since then, have unscrewed the adjusting screw cap and inspected inside. The spring and the push rod both look fine and the push rod comes out. Running the unit without the cap and push rod results in air bleeding out (as it should, I'd imagine), but as soon as I put the spring and push rod back in, the unit will still not blow off, even with the adjusting screw cap loosened all the way.

It seems a simple design (pressure pushes on push rod, which will eventually overcome the spring tension to then allow air out), but am I missing something or does someone have an idea as to what is going on? I'd find a technician, but we are in the middle of nowhere on a boat in the Maldives, so techs are a bit scarce right now!

Cheers- Matt
 
Hello! We recently serviced our 8 year old Bauer Jr. II after not having run it for about a year. Changed the oil, changed the air filter, tightened the belt (ours is electric). Started right up and everything was fine until I noticed the OPV (over pressure valve) wasn't opening at 3200 psi. Pressure increased up to about 4000 before I bled off the excess and and shut the unit down. Since then, have unscrewed the adjusting screw cap and inspected inside. The spring and the push rod both look fine and the push rod comes out. Running the unit without the cap and push rod results in air bleeding out (as it should, I'd imagine), but as soon as I put the spring and push rod back in, the unit will still not blow off, even with the adjusting screw cap loosened all the way.

It seems a simple design (pressure pushes on push rod, which will eventually overcome the spring tension to then allow air out), but am I missing something or does someone have an idea as to what is going on? I'd find a technician, but we are in the middle of nowhere on a boat in the Maldives, so techs are a bit scarce right now!

Cheers- Matt
Having an OPV open at 3200psi is highly unusual. Mine opens at about 4600psi which is the rated max pressure for the compressor. The junior is rated to pump to 300 bar so ~4000psi makes sense compared to that.

I would replace the OPV at this point and use it as intended. That is you shut the compressor down when you AL80 is full at 3100-3200psi hot. Not just start to leak
 
Having an OPV open at 3200psi is highly unusual. Mine opens at about 4600psi which is the rated max pressure for the compressor. The junior is rated to pump to 300 bar so ~4000psi makes sense compared to that.

I would replace the OPV at this point and use it as intended. That is you shut the compressor down when you AL80 is full at 3100-3200psi hot. Not just start to leak

Thanks for the reply. I just looked at the workshop manual and what I thought was an OPV valve is actually called the “pressure maintaining valve”. This is the valve that is not opening at 3200 psi. Does that make more sense?
 
Yes makes sense, you left it unused for the last year. BPR regulators become "sticky" when left unused and the spring seat set isnt exercised. A bit like pressure relief or pressure relieving valves, When you set them up they operate at set pressure or very close to it. Leave them for a year and a year later they have retained a "set" or appear to be stuck. To overcome the set you need to go well above the original set pressure to release the set or stick then they go back to the original or very near to the original normal set pressure.

In retrospect it may have been better not to have adjusted it so soon but to have just waited to see if during this re use to see if things would have eased off and the pump settled back down.
 
Since then, have unscrewed the adjusting screw cap and inspected inside.
but as soon as I put the spring and push rod back in, the unit will still not blow off, even with the adjusting screw cap loosened all the way.

Cheers- Matt

Try and put the PMV adjusting cap back in the original position and tighten the lock nut on the grub screw. To confirm whether you have the correct position, connect the fill whip to a tank but leave the tank valve closed and start the compressor.

Watch the pressure gauge on the whip as the needle rises very slowly and then all of a sudden it starts to rise very fast. Note at what pressure the needle gets to at that point......should be around 2600 psi. If not, turn compressor off and adjust accordingly by releasing lock nut and grub screw and turn slotted cap in or out and try again till you get that pressure.

To determine if your OPV is functioning on your PO/P21 housing, build up pressure and screw the knurled knob on top clockwise all the way till it vents. This is your manual override knob so remember to turn it anticlockwise again.
Good luck.
 
and if that gets stuck fully open and close it a couple of times


full.jpg
 
https://www.shearwater.com/products/peregrine/

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