Every day I will remove the braided solvent line form my back condensing coil and blow it out with N2 to get any moister out of the lines to avoid ice blocks. Then I reconnect the line and repressurize this “back end” of the system from the discharge of the Corken to the main 100# tank we use for solvent storage. This always stays pressurized, while not changing the pressure in the suction/inlet side.
We change the oil every 1.5 months as directed by the manual and wave a magnet over it to ensure we don’t see metal shavings.
This has been working well for 6+ months. On our routine maintenance, we found some “guck” on our inlet valve assembly. We took it apart and cleaned it and set it back together. After we set it back together and tried to repressurize the system pressure was going past the valves and flowing freely through the corken without the corken being on.
I thought that meant the valves were broken, so I ordered a new valve set, replaced them and im still having this same issue.
I check the piston rings and the cleaned the piston head off and it seems well and good.
Anyone have suggestions on where to go next? Or maybe who might have good advice?
I have not dissected a Corken either but operate a similar recip gas compressor.
My overly simplified version of a recip gas compressor is a check valve on either side of the reciprocating assembly. Of course the check valves are orientated such that gas can flow one direction but not the other. Meaning the check valves flow inlet to outlet and block flow from outlet to inlet.
Are you saying that gas flows from the outlet to the inlet or vise versa?
When Corken is off pressure from the outlet bleeds into the inlet side.
When Corken is on pressure goes the correct direction (form inlet to outlet).
Every morning we add pressure to the outlet side and open our storage tank and pressure usually stops at the corken, but now it is flowing through the corken into the inlet side. I assumed this was a valve issue and replaced the vavles with new ones and I am still having the same issue.
I would actually still appreciate help. From what I’ve read so far it should have been the Valve assemble or piston rings. The new valves didn’t solve the problem, I’m going to try piston rings next and still would appreciate anyone’s input! (I have also reached out to Corken via phone and website, as well as a repair person).
@ChiefK19 based on your feedback gas is moving from the output side of the pump to the inlet side of the pump, which is not supposed to happen. Assuming the pump is “isolated” enough to be sure the gas is moving the wrong direction across the pump, I would guess that there are issues with both valves. I say this because the valves in these gas compressors are essentially check valves and should flow only one way. So the gas is leaking past both valves to move from outlet to inlet of the pump.
The valves that come in Corkens are pretty bulletproof and you’ll likely hear something during operation if they’re dirty.
I think it’s possible you jumped the gun a little bit replacing them.
Did you perform this test procedure? It’s very easy to do:
Also, do you know for sure that your compressor is not equipped with a suction valve unloader? Most of the 91 series compressors (D and T) don’t have them standard but it couldn’t hurt to check. If you’re not sure post up the complete model number and I can tell from that.
Can you explain in more detail the circumstances and compressor conditions under which you are pressurizing the system?
Do you normally have the suction side pressurized or at atmosphere when you pressurize the discharge side?
Did anything change in your procedures after you cleaned the inlet valve?
If this were the case he would likely be hearing pressure escaping through the crankcase somewhere which it doesn’t sound like he is.
I do agree with you. Which Is why I ordered new valve assemblies and replaced them. After replacing them we still are experiencing the same issue! Still looking for guidance.
We did do something very similar to the test suggested. We ran the compressor with the inlet closed) and saw the compressor is able to to move pressure in the correct direction and the inlet side go sucked to vacuum quickly.
When pressurizing we are adding about 50-75 PSI to the outlet side through our condensing coil While the inlet side is at normal atmospheric pressure OR under vacuum.
Nothing has changes since changing the valve. We have not run product since noticing the pressure going from the outlet to the inlet side (which had never happened before).
I agree. I mean I followed the manual instructions I’m sure I’ve got them in the right place. And that also makes sense that the Compressor wouldn’t work at all/would have a whole set of other problems.
I bet @bc9696 was right and I’m just not able to get a good seal on the metal on metal gasket. I’ve tried really reefing those down to be best of my strength.
Check valve seat and that the valves are installed in the correct stage.
Use a screwdriver and depress the valve on the bottom and check motion. When installing, rotate to find where it drops into place.
Sticking valves can cause gas to flow backwards such that inlet sucks in then blows back out the inlet.
Bad piston rings would instead cause gas to leak from the oil reservoir at the bottom of the crankshaft or from the nameplate.
Problem must be with the valves. It’s a pretty simple system…not much to go wrong.
Piston rings blow from compressing liquid. Valves stick from getting hash in your vapor stream and then baking in the valve to form a carbon crust.
Pulling a vacuum on the compressor can pull crank oil into the head and is highly recommend not to do by corken as it can potentially damage the compressor.
