How To Test Air Compressor Check Valve

Air Compressor Check

Today’s explanation is on how to test a check valve how to

test for a defective check valve and your air compressor here we have a small

pancake six gallon portable compressor it’s an oil-free direct-drive compressor

you can see little pump there a small piston connecting rod real small little

guy but right there in the tank with the two lines coming off the large supply

line in the small nylon line is your check valve that’s a three-way check

valve write it into your tank and if your oppressor is a small portable like

this or even a large 120 gallon stationary compressor it’s going to have

a check valve and it’s going to be located in the main inlet of the tank

just like you see here it may not look just like this for instance it may look


like this be a more submersible check valve for instance a straight check

valve this would be threaded in your tank and all you would see is this

portion the compression thread essentially a hex fitting so may look a

little bit different but every compressor has one in the inlet of the

tank and it’s a check valve so it’s a one-way valve it’s going to open up when

the compressor is running to charge the air into the tank it’s going to close as

soon as the compressor shuts off to hold the air in the tank so hence check valve

or one-way valve some compressor manufacturers may call it a non-return

valve one in the same kind of description of course all right so it’s

the most common problem I would say with any air compressor period we’re going to

have a defective checked out if the unit leaks back after shuts off and so what

you’re going to do to test this pretty simple all right you’re going to fire it

up and I’m not going to do it here for the sake of the demonstration pretty

loud you won’t be able to hear me but you essentially charged-up turn it on

and when it reaches maximum psi maximum pressure the pressure switch will shut

it off and you’ll notice a leak come out of the the check valve but it would probably

leaked around the pressure switch you have a Dan loader valve which wrestling

this and loader line all the way to the unloader valve on your on/off switch so

the unloader valve may look like something like this on a larger compressor

here’s your pressure switch with the cover off your unloader valve right here

which is small nylon quarter-inch bleeder lineman attached to a lot of

times you’ll notice when after it shuts off the air will escape it continuously

bleed added loophole out of this valve the inlet valve with a quarter-inch line

attaches if it does leak out of that area constantly after the unit shuts off

you have a defective check valve it’s not sealing is probably debris from the

pump head could be any kind of debris or even moisture from the tank is cause it

to rust and there’s a little diaphragm or a bowl and spring inside and it

doesn’t close hence it’s going to back feed all that tank pressure from your

tank through the line and mains discharge line and also put back

pressure on your head which is no good as it could blow out a gasket and it’s

going to leak back through the motor line and again leak out of your unloader

valve so that’s the telltale sign of a bad check valve when you shut it off it

will bleed air usually out of this valve through the bleeder tube and that’s case

it will constantly run it will link back down cut on when it’s supposed to try to

recharge their shutoff and continue to leak so it’s a cycle so really common

problem the berries that fix a lot of times you can even clean these check

valves there’s a little diaphragm side here a lot of times you have just junk

or debris inside you can clean it out if not replace these we do have them they

sell anywhere from about fifteen to twenty dollars or for something like

this even less expensive very easy fix and it will take care of that leak and

cause a lot of problems if you don’t so that’s how to test your check valve get

any questions go online you can take a look at the various types of check

valves we offer if you click on generic air compressor parts click on check

valves from there and we have them read about different types compression style

fitting three ways like this or just search by your model number part number.


Source : How To Test A Check Valve (One-way Valve) On An Air Compressor

Share This Post

Post Comment