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Fittings leaking

APW

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Where the check valves meet the brass nipple, leaks under high pressure. I have taken them all off and retaped them but they still leak only when HP is running. Not sure if I over tightened them or what. They are bottomed out. Anybody got any suggestions? 20211023_105206.jpg
 

HeyVern

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Do the check valve and the nipple have the right threads? The brass nipples could have compression threads on that side.
 

MEP001

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Do the check valve and the nipple have the right threads? The brass nipples could have compression threads on that side.
That's a possibility. Pipe thread into the check valves shouldn't bottom out.

Just curious, why three check valves on the left side of the manifold? I use one for the three combined, tire cleaner/presoak/air. They're all roughly the same pressure so nothing backfeeds, and less to go wrong.
 

APW

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Just curious, why three check valves on the left side of the manifold?
Because I am an anal kind of person and try to prepare for worst case scenario. The brass hex nipples are standard male pipe threads on both ends. Nothing different about them that I can tell.
 

HeyVern

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We once had a check valve with British Standard Threads, it threaded onto standard 3/8 pipe thread but, not tight enough to seal. I would be surprised if that was your problem though. Only other thing I can think of, is there might be a crack in the valve or nipple that opens under high pressure.
 

Joswhaha

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I am not experienced in car washes but am in pipefitting. Fitters Frequently use Teflon tape then apply pipe dope over the Teflon tape. I don’t know if it will help your situation but thought I would mention it since this forum has been so much help to me.
 

MEP001

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You would normally use both tape and pipe dope on larger fittings, but it shouldn't be necessary on 1/4 and 3/8" pipe thread.

The check valves pictured are almost certainly not British straight threads.

I'm still curious about them "bottoming out." Tapered pipe threads should get tighter and tighter until it can't be turned anymore or breaks.
 

PaulLovesJamie

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I've had hairline cracks in brass fittings, but usually in the female side of the fitting.

The check valves in your pic dont look to me like theyre bottomed out, are you certain you cant tighten them further?
 

washnshine

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Also - try gas Teflon tape - the yellow kind. I was re-taping something that leaked once and I was out of white (water) and only had yellow. The yellow seems denser to me. I can’t say that for sure though but it did the trick. Not saying because it was yellow, but maybe it helped.
 
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Twodose

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I am not experienced in car washes but am in pipefitting. Fitters Frequently use Teflon tape then apply pipe dope over the Teflon tape.
We always did pipe dope first, then the tape. Also plumbed a whole wash using teflon tape and blue rtv on top, not one leak on that whole job, also like Randy said the leak lock blue works great also.
 

MEP001

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I've built at least 50 sets of equipment using blue Loctite on all fittings except for anywhere something will need to be serviced, like check valves, solenoids, and regulators. I've had a couple guns stolen in the last month, so I've picked up a bottle of red Loctite for those.
 
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Quick off topic question. Are these manifolds sold pre-built? My old system that I am replacing was all injected at the ER and not above the boom. I am redoing all my high pressure lines and want to set it up like this.
 

wrightwash

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I switched from the white teflon tape to the blue Monster tape and I'll never go back! I've not had one leak issue since.

 

MEP001

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They also have 1/4" wide Blue Monster tape. I'll have to try it. I carry 1/4" and 1/2" tape, 1/4" for hose fittings in the bays so there's never frayed ends of tape coming off. Looks trashy IMO.
 

Kar B Kleen

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I switched from the white teflon tape to the blue Monster tape and I'll never go back! I've not had one leak issue since.

As far as thread tape goes, it's absolutely the best.
 

OurTown

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I'm also having an issue with threads bottoming out. 1" Hypro mesh strainer with a brass ball valve that has a male thread. This is dry fitted and tightened by hand. I tried a nylon fitting and it did the same thing. The mesh strainer is made in China so there's that.

IMG_20230303_121021470_HDR.jpg
 
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