DIN inserts leak ?

[JB]

I wonder if there is knowledge about this issue? I have tank valves with DIN inserts. These were supplied by Scubapro? The problem is they don't take a standard 012 o-ring and in fact it is difficult to fit any o-ring 010 or 011 without it falling out all the time. I have a total of 6 DIN inserts that accommodate the standard 012 o-ring, but all but 2 of them leak, and blow the o-ring within seconds of turning on the pressure. The problem with all of them is the diameter of the central hole this seems to vary from 11 to 13mm. My regulator has an internal diameter on the mating part of 12mm. So the only inserts that don't leak are those with a diameter of 11mm. I would have thought this must be a common problem, but could not find any references to it on the internet. Maybe it's just my regs that have a larger than standard mating part. I don't want to switch to DIN, because I travel a fair amount and yoke seems the most common connection. I would have thought the dimensions are standardised, but every time I buy new inserts they just don't work.
Any suggestions?

 

[spectrum]

I know the fit in my Thermo inserts is a little sketchy but it does work.

What I have learned is to barely tighten them. I hold the short end of the Allen key and use only my thumb and forefinger. If you crank them in they will align with the lead of the thread, go askew and be a bear to get a seal from. This will be frustrating with fill whips and blow rings.

Also be sure the inserts are dead clean. If any silicone on on them the o-ring will be encouraged to flip out.

Pete

 

[DA Aquamaster]

I have a combination of Scubapro and Thermo valves and the inserts are basically interchangeable as I have never had issues with leaks or improper fit.

 

[redacted]

I also interchange between Scubapro and Thermo inserts in my HP tank but I have to watch the o-rings I am using. The Scubapro insert wants a different sized o-ring. I believe I am using 2-111s or 2-112s, depending on the insert. Both are a bit fatter than the 2-0xx you are having trouble with. As I recall, the Scubapro insert takes the 2-112 on both the inside and the outside of the insert.

 

[idive2]

Yeah, it gets real crazy with the different inserts and o-rings. I had an
insert on an HP100 that was fine for a while but when it came time for
a new o-ring on the insert the 112 was actually a larger inside diameter
than the inside diameter of the insert. You could push the o-ring in there
but it would not stay. I think I tried the 111 which is a slightly smaller o-ring
and it did not fit quite right either. (both of these were the fatter o-rings
I think .103 in. thickness). I ended up getting another insert that took the more
standard o-ring. I never did figure out if the inside o-ring takes the same o-ring.

 

[WD8CDH]

If the leak is at the regulator side of the adapter, not the valve side, the ID shouldn't matter much. The seal is between the outer part of the face of the regulator and the o-ring. Is the sealing face of the regulator nicked, dented or rounded?

For some reason, most of the DIN adapters seem to follow the old fat yoke o-ring dimensions rather than the smaller thinner HP yoke o-ring pioneered by Sherwood in the 80's that easilly handles 4000+ psi.

 

[JB]

Thanks for all the replies, it's nice to know I'm not the only one with this issue. It was my mistake the o-ring sizes were indeed 111 and 112. I think the rest of the problem relates to my particular regs. The diameter of the central hole must be smaller than average as it binds on the centre post of the insert and prevents flush sealing. I will have to look for inserts with a center post smaller than 12 mm to allow the reg to fit flush with the insert. (The internal diameter of the 112 o-ring is 12.77mm)

 

[WD8CDH]

The diameter of that part of the adapter should be 10.87mm per CGA specs.