Worthington valve insert

[mark99]

Just got my new 120 cf tanks and noticed the DIN-Yoke converter insert has a funny looking "ding" in the inner rim just toward the center from the O-ring. I thought this was damage to the insert, but it is the same for both tanks. If these are the same Thermo valves with the inserts that were shipping on the PST tanks, I know there were at least 3 versions of the insert last summer (none like this, though). Thoughts?

 

[cummings66]

I've seen those dings myself and wondered what they're for. My pet theory is that it's for a controlled leakage when you first hook the yoke up and then the o ring expands and seals the gap.

Who knows for real?

 

[JS1scuba]

its normal to have that dimple -- its used to easily remove the o-ring when its time to change it ---

there is NOTHING wrong with it.

Regards,

 

[Dave in PA]

I've seen those dings myself and wondered what they're for. My pet theory is that it's for a controlled leakage when you first hook the yoke up and then the o ring expands and seals the gap.

Who knows for real?

Joel knows!

I personnally think it also helps to retain the oring in the seat.

 

[XS Scuba]

Hi Dave:
Actually, you are correct. Thermo added the dimple to scuba valves more then 20 years ago. The dimple was added to improve the retention of the o-ring within the o-ring grove. Prior to the dimple, it was not uncommon when removing your first stage at the end of the dive to have trapped pressure behind the o-ring "pop" a small part of the o-ring out of the grove.

I ersonnally think it also helps to retain the oring in the seat.