Lil air leak from bottom hole on tank valve

[Fishpie]

.....just as I thought.

 

[Bubbletrubble]

Fishpie is the winner! What threw me was the OP's description of the location of the hole. It's actually on the underside of the DIN outlet.

 

[Fishpie]

WhooHoo

 

[redacted]

On my Thermo din valve, that hole vents from an ambient pressure area in the lower threads. It normally sees no pressure other than ambient. That leak suggests the o-ring is not sealing. Inspect the sealing surface inside the valve and try another o-ring.

 

[spectrum]

It's also possible that the O-ring seal is good but the DIN connector broke away internally. Its usually a 3 piece affair and it can loosen if mis-torqued. There is a static o-ring in there.

Pete

 

[Bubbletrubble]

It's also possible that the O-ring seal is good but the DIN connector broke away internally. Its usually a 3 piece affair and it can loosen if mis-torqued. There is a static o-ring in there.

Pete

@spectrum: If that were the problem, wouldn't the reg leak when it's mounted on another tank valve? The OP stated that when he used a different DIN tank valve, there was no leaking.

 

[Scared Silly]

The only way to get a leak out of this hole is if there is not a good seal between the base of the valve and the o ring on the DIN connection of the reg.
This could be caused by debris inside the valve, a worn o ring or not screwing the reg in far enough.
......in this case (since you indicate you are using a new o ring) I'd guess it is the latter reason.

I would agree with this diagnosis but also suggest examining the threads. Quite often the threads can have damage which prevents the reg to fully seal. I had this problem with a provalve and the insert which had thread damage.

 

[spectrum]

@spectrum: If that were the problem, wouldn't the reg leak when it's mounted on another tank valve? The OP stated that when he used a different DIN tank valve, there was no leaking.

That sort of damage to the face in a valve would be real hard to do. He could easily be making and breaking the union in the DIN swivel when switching cylinders.

 

[Bubbletrubble]

That sort of damage to the face in a valve would be real hard to do. He could easily be making and breaking the union in the DIN swivel when switching cylinders.

Hmmm. So if the OP went back and forth several times between the two tank valves, your hypothesis would be that he'd observe leaking when attaching the reg to either of the tank valves...sometimes. Interesting. I guess that's possible.

It should be fairly straightforward for the OP to ensure that the DIN connector bolt is torqued properly. Maybe he should check that.

Scared Silly brings up an interesting possibility.

 

[Fishpie]

.....it could possibly be an intermittent leak at the o ring that seals the join between the end cap of the DIN adapter and the main DIN tube of the adapter (depending on the make and model).

It's unlikely to be the at the other end of the adapter that is torqued into the 1st stage body since any leaks here will be seen coming around the plastic saddle of the 1st stage.

My bet is still on the reg not being fully screwed into the valve itself. Ask the shop to run a tap down the inside of the valve to remove corrosion.