Question Apeks DST Valve Body to Handwheel connector Leak. Help!

[divebutt]

Hi,

Working on reg with a leak coming from the joint between the valve body (AP1480) and the Handwheel Connector (AP1471). Bubbling out from the threads. Tried new o-rings, checked o-ring sealing surfaces (good as new), cleaned everything multiple times, etc. Then, I swapped connectors with another reg, and the leak seems to be the result of an issue with the valve body.

Before just replacing the body, is this anything anyone has seen before? Any fix?

Thanks!

 

[happy-diver]

Do you screw the fitting UP into the reg so as not to dislodge the oring

 

[Centrals]

I had ruined couple of O-rings before until I decided to screw the Connector(AP1471) up to the body(AP1480).

 

[divebutt]

Do you screw the fitting UP into the reg so as not to dislodge the oring

Yup, o ring was seated fine - tried multiple o rings on multiple connectors - same result. It's a very fine leak - not audible, only able to notice when submerged.

 

[Still Kicking]

Yup, o ring was seated fine - tried multiple o rings on multiple connectors - same result. It's a very fine leak - not audible, only able to notice when submerged.

I had the same situation yesterday ...regulator body I found in an old parts bin was damaged at the threads even though it looked good with a loupe.

In my case i am guessing it had been over torqued at some point?

 

[divebutt]

I had the same situation yesterday ...regulator body was damaged at the threads even though it looked good with a loupe.

In my case i am guessing it had been over torqued at some point?

That's my guess - customers reg and haven't worked on it before so not sure of the history. Interesting part is the threads have nothing to do with the sealing. Only thing I can think of at this point is to replace the body.

 

[davehicks]

When I have seen this problem it was because the o-ring was too soft. Use a higher duro o-ring.

 

[Tanks A Lot]

I think the main culprits have been raised already.

1. Someone over-torqued the assembly, warping the body. This can be very hard to spot with the naked eye and I indeed had troubles measuring deformation damage in the past. Aqualung had some issues around 2010 with people over-torquing their Yoke assembly and posted pictures. This is directly applicable to your DIN assembly as well. Do not only look for deformation, but also cracks. I have seen regulator bodies develop hairline cracks from over-torquing. A bright light is a good tool to find these cracks, although I had troubles in the past where a crack would only be noticeable under load.
2. The O-Ring gets dislodged on assembly. This is easily prevented by assembling the whole thing upside down and as you mention not your issue.
3. Scratched sealing surface on either the body or the barrel. As you swapped out the barrel, this is surely not it. A scratch on the sealing surface inside the body should be easily visible. Why someone would poke inside a Apeks DST in that region is beyond me and you would have spotted a scratch already.
4. The O-Ring is too soft. All manufacturers I know specify either a an O-Ring with a 85 or 90 shore rating. A 70 shore O-Ring can lead to a leak, although it usually does not right away.
5. Your O-Rings are damaged. While they may look good to the naked eye, they can have hairline cracks in them which will prevent them from sealing properly. This does not happen to a single O-Ring, but always a whole batch, when something goes wrong at the factory. It could be that your whole bag of O-Rings is damaged.

It would be interesting to hear what it was in the end.

 

[davehicks]

When I had the too soft oring problem, it manifested by "popping" a puff of air when the valve was opened, then sealing. I was using o-rings from an Apeks service kit, but maybe I installed the wrong one? Are there multiple duro orings of the same size in the kit?

Anyway, I pulled the o-ring and found a 90 duro o-ring of the same size from one of my bulk o-ring variety packs and that seal the reg perfectly.

 

[rsingler]

Only thing I can think of at this point is to replace the body.

Good luck with that. I've been waiting 3 months for a replacement for a guy with a scratched volcano from a previous technician.
Company financials are worrisome.

As has been pointed out, the threads shouldn't matter. It's a face seal on the reg body and a side seal on the DIN bolt. If the two surfaces are perfect, I don't get it. Even a lack of parallel faces shouldn't leak. Extrude maybe, but not leak.

Maybe try a 70 duro oring (only) in the shop. That might seal to a microscopic imperfection better than a 90. Then again, @davehicks had the opposite result. In any case, you can't release it to the customer that way, but it might point to a cause. Other than that, I have no suggestions.