Tank valve opens spontaneously

[Hiszpan]

Hey guys,

I have steel twins. One of the valves was closing at the very last turn and there was no more movement to be applied to turn it off more. It happened on two occasions that after filling the tank to 232 bar, that valve opened slightly by itself and was leaking air.

I have serviced the valves, replaced the posts and other parts and the same thing happened yesterday. The knob now has some turn left to be closed fully off, but I do not want to close it forcefully to the end not to strip the rubber from the post again (which was the case when I serviced the valves and took the old posts off).

What am I doing wrong? The valves are a European San-O-Sub brand and the service kit was for that brand.

I had aluminum twins before with Thermo XS valves and never had that problem before (serviced it myself too).

K.

 

[jadairiii]

Valves dont open by themselves. Most likely the seat is bad.

I had a sherwood din valve that started doing that, you thought it was closed but as it cooled, it would start leaking. I would have to crank the crap out of it before I finally got around to fixing it

 

[Hiszpan]

But I changed for the new seats two days ago...

 

[jadairiii]

But I changed for the new seats two days ago...

The valve orifice that the seat goes into my be defective?

 

[tbone1004]

brand new seats take a "set" this is why first stage valves have to be cycled. When you have a brand new seat, as it cools off everything contracts and it is going to leak. It will continue to do that until it takes a proper set so I wouldn't worry about it too terribly much.

 

[Texasguy]

Get a new valve ($40) from dive-gear-express and forget about it.