Leaky tank valve knob?

[CaveSloth]

When I close one of my tank's valve too tight, I can hear it leaking from the valve knob. Are there some o-rings in there I can replace myself? Are they a standard size or is it brand specific? What size is it? Should I take it apart myself? Depressurize first?

 

[tbone1004]

If it leaks out of the knob when it's open, then it's an O-ring you can replace yourself if you have the notched screwdriver *EVERY diver should have one of those btw, linked below. If it's leaking when it's too tight, then that's really strange and you will probably need to depressurize and fully service the valve since the only thing that can leak when it's closed is the valve seat itself and that can't be done while it's pressurized. Supposed to rebuild at hydro time. The valve kits are brand specific, and the o-rings are sometimes sized by valve type, though you can usually look them up on here or on the manufacturers parts explosion diagrams. They're usually standard though. On a single tank valve, all of the o-rings can be changed without depressurizing, but the valve MUST be off when you do it as you can't disturb the valve seat or bad things will happen. I do not recommend doing any valve work other than tightening/changing the knobs without at least informal training from someone who knows what they're doing.

Inflator Service Tool w/O-Ring Kit | Dive Gear Express®

 

[CaveSloth]

Well, shitzu.

 

[tursiops]

the valve MUST be off when you do it as you can't disturb the valve seat or bad things will happen.

Love it.

 

[tbone1004]

Well, shitzu.

If it's for a single tank, just buy a new valve and deal with it later. DGX has surplus Thermo valves for $25. If it's on doubles, or is a plugged doubles valve for sidemount, then you're better off rebuilding it.

 

[CaveSloth]

It's doubles. I am going to try to take it back to where I bought them from and see if they can do a rebuild on the valve. How long should that service usually take?

 

[Miyaru]

Here's an example of a valve seat that has reached its end of life. The teflon is almost completely gone and won't seal anymore. Result of over-tightening the valve.

 

[tbone1004]

It's doubles. I am going to try to take it back to where I bought them from and see if they can do a rebuild on the valve. How long should that service usually take?

if you bring it drained, about an hour plus fill since you should probably have all 3 valves rebuilt at that time. If you bring it full, about 2 hours since it takes a hot minute to drain doubles.