cat pump 5cp2120 safety pop off valve

[slash007]

I have a 5cp2120 (same as 310) cat pump and whenever the pump is run or the weep kicks on instead of water coming out to the bay it runs out of the safety pop-off valve and straight to the floor. Does that mean that the safety pop off valve is defective, or is is a sign that something else is wrong? I went to buy one and in the description it said "Pop-Off valves are used as a back up to your regulator or unloader. They are designed to protect your pump if the regulator or unloader fails"

Does that mean that possibly my regulator or unloader failed? What is the best way to test what might be wrong?

I just shut the bay off for now, but need to get it repaired before it gets cold again as it won't weep.

Thanks.

 

[Greg]

Hi Slash007,
Correct, the pop-off is safety backup in case your main regulator ceases to work.
Being the pop-off leaks at low pressure, it may be worn or stuck open because of debris stuck between the ball and seat.

Remove pop-off valve and plug port.
Back off the pressure regulator before restarting the pump, then re-set pressure to your desired set point.
** Keep an eye on the pressure gauge in case the regulator is not functioning as it should.

Unless the regulator is bad, that bay can opened and making you money in minutes.

Thank you,
Greg Thoennes
Arimitsu Pumps

 

[MEP001]

The pop-off is supposed to self-reset if it comes into play. Since it's not leaking with the pump running, it's obviously bad.

Are you using a regulator or an unloader? Bypass regulators rarely fail and cause an overpressure issue. From my experience, they just leak. Unless you're using an unloader, you can safely remove the pop-off and plug the port.

 

[slash007]

It actually does leak when the pump is running as well. I plugged it for now so that the weep water will go to the bay. I also tried running the pump and it seemed to run at the same pressure as before. Not sure if I'm using a regulator or unloader as I am not really familiar with the setup, I just recently purchased the wash. I can post pictures, but not sure the best way to upload them here. Thanks.

 

[MEP001]

The easiest way to post pictures is to upload them to an external hosting site (I use imageshack.us which is free, and when you register they store your photos as long as you want) and paste the forum link right into your reply.

This is an unloader:

They mostly look the same. They are meant to be used with a shut-off gun so the pressure on the pump drops to zero when the flow stops. They don't work that way on a self-serve bay with a weep gun.

 

[slash007]

http://imageshack.us/photo/my-images/84/20120914120909.jpg/


Pictures of my setup. Thanks.

 

[MEP001]

Both those are bypass regulators and not something prone to fail where the pump will need a pop-off. You can just remove the pop-off and plug the port and not worry about it.

(To get the image to display in your post, either use the insert image button and paste the link or wrap it with [ img ] [ /img ] tags with no spaces.)

 

[slash007]

Thanks for the tip in the image. I will just keep the port plugged. Any idea why they were originally installed if not needed?

 

[MEP001]

It's recommended in the Cat manual - it's also recommended to have a high-temp pop-off and a "Captive Acceleration Tube" on the inlet when the feed isn't pressurized, but almost no one does.