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Support Equipment For PCP/HPA/CO2 and springers ,rams => Support Equipment For PCP/HPA/CO2 => Topic started by: Thiel on November 30, 2018, 05:50:07 PM

Title: Yong Heng leaking out low pressure side Pipe
Post by: Thiel on November 30, 2018, 05:50:07 PM
Hey guys,

my jong heng starts leaking out of the connection pipe from the low pressure side to high pressure cylinder side.
i tried to tighten it up but it still leaks.

can you help me to identify the thread ?

Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: truck on December 01, 2018, 01:08:55 AM
If the air is leaking where you have it circled I'd be looking at the compression fitting. 
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: Thiel on December 01, 2018, 04:30:41 AM
yes, thats the leaking spot.

the compression fitting = pipe ?

it seems to be a press fitting

i cant remove the nut further because the bended part of the pipe is too wide

these two surface areas look good to me

if pushed together by hand i cant feel any resistence or slack
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: Norm_m on December 01, 2018, 09:09:56 AM
I had issues with the compression connections leaking on My YH and with the short bends on the tubing making it impossible to slide the compression nuts back you should remove the tube form the compressor and blow out the area inside the nut with air to make sure there is no tiny pieces of anything around the ferrule. I then apply a tiny bit of White Lithium lube around the ferrule on the tubing. Use two wrenches when installing the nut back on, one on the nut and one on the fitting.
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: tracker1955 on December 01, 2018, 01:38:05 PM
Unfortunately, these are metric compression connections and may be hard to source without ordering them from China through aliexpress. If you cannot get them to seal by just tightening the two connections alone I would try about two wraps of teflon tape around the ferrel and then re-tighten the nut again. The teflon will bunch up around the ferrel and get jammed up between the nut and fitting enough to make a seal. I've done this many times before with plumbing, just haven't tried it on something with a lot of pressure though, fortunately, it's on the low side and not on the high side. Hope you get it sorted out.
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: Hoosier Daddy on December 01, 2018, 01:50:31 PM
Push the top blue button on your calipers that says "mm/inch". Also, metric threads are measured in how many centimeters it is for 10 threads not threads per centimeter.
That will help you find the right metric fitting.  ;)
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: dlee on December 01, 2018, 02:45:06 PM
fyi- i measured the fittings on mine awhile back and labeled a couple of pics. This was before I installed the cyclone separator between the 1st and 2nd stages. But here they are for reference...
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: elguapo99 on December 01, 2018, 05:15:38 PM
I would use a flare nut wrench to tighten those fittings so as not to distort the fitting on the tube.
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: truck on December 01, 2018, 05:19:40 PM
McMaster-Carr sells metric compression fittings.  https://www.mcmaster.com/# (https://www.mcmaster.com/#)
Title: Re: Yong Heng leaking out low pressure side Pipe
Post by: Thiel on December 02, 2018, 04:37:33 AM
wow, thanks for your help.
i had not expected that they use metric threads lol. now it is much easier for me :)

my leak is sealed but i dont know how exactly i did it. i used loctite 290, waited a few hours, turned it on - leaked again. tightened a little more (i know the loctite broke) but it was sealing now!!
but the pressure still did not went up :(

checked all screws and connection with soapy water - nothing. uncrewed the burst disks a tiny bit - bubbles, okay this should happen with soapy water.  8)
i prepared myself for a last try and the needle went crazy fast up (im using a dead end plug / test plug in the filling hose) i stopped at 3700psi. i filled a few small air pistol cylinders to 3000 psi and it looks good to me for now.
dont ask for explanations  ;D  ;D  ;D