Tank Valves, O-Rings and RAM

[rstofer]

I took my RAM to the pool today and before I could even get it wet, the Viton o-ring between the tank valve and the banjo fitting blew out. It's an 014 o-ring.

I replaced it with a black (Buna-N?) o-ring and left off the banjo fitting. I blew that out with just the reg connected.

I am beginning to think that these old regulators might do better with older valves using larger diameter o-rings. I didn't have any problem using my PRAM on an old LP 72 I grabbed out of the pile at the LDS and I haven't had a problem with my Mistral on an old J valve but that's at much lower pressure..

I think my ProValves use a larger diameter o-ring as well.

Anybody else have problems with specific valves and o-rings? I am willing to replace the valves with either Pro Valves or older J or K valves if that is the solution.

Oh, and I finally got the PRAM wet. It works very well!

Thanks
Richard

 

[DA Aquamaster]

I have not had issues with either scubapro valves or Thermo DIN/K valves.

 

[james croft]

What brand banjo do you have? Is it a vintage banjo or a new VDH reproduction ?

 

[Greg Barlow]

Like DAAM, I have had no problems with Thermo valves. I typically have used vintage Voit valves, but one of my 72s has a modern Thermo. I have also had very good results with a Genesis version.

Greg Barlow

 

[rstofer]

Yes, this is a VDH reproduction banjo. But even if I remove it from the stack, I blow the o-ring with just the RAM mounted. This was a brand new o-ring so it wasn't a matter of prior abuse. It's funny how this stayed together on the work stand for a couple of days and then, the very moment I wanted to actually use it, the o-ring blew out.

I was looking at my Thermo DIN/K valves (typically on my HP 100s) and they have a much larger diameter o-ring. Unfortunately, this particular Al 50 didn't come with such a valve.

I picked up a couple of Dacor J-Valves off eBay last night. I think I'll walk away from the banjo idea altogether. I have no problem dedicating an SPG to a tank.

Someone did say that the port is depressurized when the valve is closed, right? I would sure hate to unscrew the plug on a pressurized port.

Richard

 

[captain]

Yes the port is depressurized when the valve is closed

 

[halocline]

Slight hi-jack; I have a voit K valve that's bubbling a little with the valve open. I've never rebuilt one of these things, but I seem to have heard that the o-ring that seals the stem is a 010, is that right? I'd like to find a rebuild kit for this valve, any chance of that?

Thanks!

 

[captain]

Slight hi-jack; I have a voit K valve that's bubbling a little with the valve open. I've never rebuilt one of these things, but I seem to have heard that the o-ring that seals the stem is a 010, is that right? I'd like to find a rebuild kit for this valve, any chance of that?

Thanks!

A lot of the early valves had no O rings at all. Most use a teflon packing and a lot of the bonnet nuts are a metal to metal seal or use a copper crush washer to seal. If you take it apart you should be able to find the teflon packing. I have cut my own teflon packing from 1/8" teflon sheet. Valves are simple devices. You need to remove the hand wheel and with regulator attached open the valve and submerge it so you can see exactly where the leak is. Is it at the stem or is it at the gland nut. If it is at the glan nut try tighting it. With the valve securely closed you can safely remove the glan nut and stem on a full tank to change the teflon packing.

 

[herman]

I have never had any problems with modern valves and DAAM, RAMs, Mitrals and banjos. And believe me if it was going to happen I would have seen it over the last 4 days....Grand Bahama has not seen that many DH regs on dive boats in a long long time. There are several well know SB members in these photos. We were using AL-80s and modern valves.