Need yoke solution for Sherwood (7/8) tank

[halocline]

turn down a 200bar convertible valve from 3/4 to 7/8, but that is violating a whole lot of rules and realistically isn't safe because of yoke o-ring extrusion at high pressure. The 3500psi tanks are 300bar only for a reason...

Do not put words in my mouth though, I never once said "it isn't safe" hell I never once used the word safe.

 

[tbone1004]

touche, that was in reference to turning down the valve more than anything, but i'll yield to that one. make sure you are buying 90duro o-rings btw. Scubapro only has their yokes rated to 3300psi, so don't overfill the 3500psi tanks if you're going to do it. Read up on ISO standard 12209 as that is what defines the pressure ratings, and make damn sure there is no marring on the yoke face seal on the regulator or the tank valve from o-ring picks or any other abuse. I've seen a lot of yoke o-rings extrude at >3000psi, don't be one of them. The worst ones are when they extrude when the regulator is bumped when in the water and the reg may not be able to function anymore.

 

[Doby45]

Personally, I have a machinist friend that could mount a 300BAR DIN valve in his mill and shave it down to the same specs as a 200BAR DIN valve. Already has the dimple in the back..

 

[Keith.M]

Personally, I have a machinist friend that could mount a 300BAR DIN valve in his mill and shave it down to the same specs as a 200BAR DIN valve. Already has the dimple in the back..

I'd have to see that. Why would it have a dimple when a 300 bar din valve is too long for a yoke to fit over it in the first place?

 

[tbone1004]

some have them because they use the same valve manufacturing and will just shave down the valve outlet a bit more on the 200bar valves, saves in manufacturing.