schrader valve question

[jlaird]

So I'm planning my air plumbing and want to put a schrader valve at each bag for emergency situations. I'm wondering where it exactly needs to be located though to be effective. I'm thinking it has to be between a bag and the valves, however wouldn't you need a manual ball valve between the schrader and the electric valves? The reason I ask this is because say for instance a dump valve malfunctions and is stuck open. The bag wouldn't be able to be filled manually unless there is a shutoff in the air line between the schrader valve and electric valves. Follow me? So it would go bag > schrader > ball valve > electric valve.

Second unrelated question: Does the check valve go between the tank and valves?

thanks fellas!
josh

[Slmd92DIME]

Hhhmmm... i just use a shrader valve on my tank to fill it up just in case I would have a problem with the comps. If you dump valve would happen to stick open just smack it with a wrench a few times it will close. LOL For the check valves im not sure I have never ran them

[SCOTI]

What about using a piece of line w/the schrader attached but don't install it in the system. If you have a failure, just disconnect the problem line & attach your 'emergency' piece & air it up.

[PrerunnerRob]

Originally Posted by jlaird

So I'm planning my air plumbing and want to put a schrader valve at each bag for emergency situations. I'm wondering where it exactly needs to be located though to be effective. I'm thinking it has to be between a bag and the valves, however wouldn't you need a manual ball valve between the schrader and the electric valves? The reason I ask this is because say for instance a dump valve malfunctions and is stuck open. The bag wouldn't be able to be filled manually unless there is a shutoff in the air line between the schrader valve and electric valves. Follow me? So it would go bag > schrader > ball valve > electric valve.

Second unrelated question: Does the check valve go between the tank and valves?

thanks fellas!
josh

question 1
Sounds good, it only take a little bit longer to plumb in the scraeder and isolation valve, the key is doing it the way you stated, and being able to completely isolate the system downstream of the electric valves. This will save alot of headaches IF the electric valves should ever give you problems.

question 2
If i remember correctly, the check valve goes between the compressor and tank, to stop the tank pressure from trying to backfeed through the compressor.

[jlaird]

Originally Posted by PrerunnerRob

question 2
If i remember correctly, the check valve goes between the compressor and tank, to stop the tank pressure from trying to backfeed through the compressor.

Yes, this is accomplished by the check valves that come on all Viair compressors.

However, I think you need the check valves between the tank and valves also. With the valves that we use, back pressure keeps them closed. If the tank pressure falls lower than the bag pressure, the bags will deflate if there is no check valve between the bag and tank. This could happen from a compressor failure, pressure switch failure, etc.

I just wanted to verify the above. That's why I asked the question.

[bedsled71]

yep thats what happend to me once.. had to drive about 4 hours at really low speed because my control arms were about an inch off the ground.. sucked

[jlaird]

Originally Posted by bedsled71

yep thats what happend to me once.. had to drive about 4 hours at really low speed because my control arms were about an inch off the ground.. sucked

Have you modified your plumbing at all to prevent that from happening? If so, what?

[PrerunnerRob]

I had totally forgotten about the pressure differential requirements to keep the valve from opening. So you should need a check valve between each fill valve and the tank, in addition to the compresor check valve.

[lowrollin70gmc]

I have check valves between the compressors and tank and also between the tank and valves, that way if the air leaks out of my tank, it doesn't leak out of my bags. That way when I drain my tank, my hand isn't being squished!

[bedsled71]

what i did was got a check valve between the tank and valves, carry and extra pressure switch and have schrader valves hooked up to T fittings so if i have to, i can put those into the bags

[jlaird]

Originally Posted by bedsled71

what i did was got a check valve between the tank and valves, carry and extra pressure switch and have schrader valves hooked up to T fittings so if i have to, i can put those into the bags

sounds like a plan!