Scuba tank valve service?

[mmimadi]

I just bought a used al 80 tank, made in 2005. Hasn't been used for several years but had air stored in it.
It's need maintenance.
I will take it for hydro and vis and change the o rings.
However, it's been mentioned to me by someone online that it needs to have valve service? However, I've never heard of Valley service until they mentioned it. Google doesn't say anything besides hydro and vis being neseaxry.
Should I have the valve serviced?

 

[redacted]

There is a seat and a couple seals that can be replaced. Many folks, including myself, seem to wait untl there is an indication of a problem before performing service. The failure mode tend to be inconvience rathr thann dangerous for OW divers.

 

[fmerkel]

Valves are mechanical devices with seals. Those seal need to be able to deal with 3000+psi. The threads are soaked in saltwater, almost never fresh water soaked, and get pretty corroded. Rinsing does not get the salt out of threads. They tend to not be treated 'nicely', more like slammed open and shut.

Yes, they should be serviced. How often depends on use, beliefs, paranoia or lack of same, time, use...etc.I tend to do them each Viz, never go more than a hydro.

I just did a tank valve that probably has not been serviced for about that long. Inherited it from a friend. It's seen very little service for years. I had to have my wife hold the knob with channel locks while I removed the slotted nut that holds the knob on. I have a really high end tool just for that job. VERY corroded. It can reach a point of 'no return-no removal'.

Note - If you do not replace the actual seat, which you don't need to do if it's sealing properly, you can overhaul a valve in place, with air in the tank. Not the burst disk though.

 

[Bob DBF]

If the valve is clean, no visible corrosion, and works fine the only thing I would consider is to replace the burst disc as there is no way to tell what condition it is in and once you take it out to look it should be replaced.

I work on my own gear and think valves are a good place to start if you are thinking of DIY as they are quite simple and relatively cheap used.


Bob

 

[fmerkel]

Is replacing the bust disk at hydro industry standard?

Re - pulling and replacing burst disks. Why?
You can't much tell what they are really like when new. What harm does pulling and putting them back do? Mostly seems like you are just re-smushing the copper washer. It's not like there are moving parts.There's something in there that gives if pressure becomes excessive. Does time and/or corrosion degrade that mechanism?

When I'm doing a major off the tank overhaul of a valve I pull and put them back (not replace) them routinely. No harm done.....so far.....

How long is a burst disk good for? If not replaced during hydro I know of some that got to be 10-20 years old.

 

[Tug]

For strictly recreational tanks, I don't really see the need to service the valves on a regular basis. Like awap said, I'll service them if there is any indication of a failure or if they start to become stiff. With my bailout tanks I'll service them at minimum of every five years when I take them for a hydro or if they become stiff beforehand. For any tanks that routinely see higher oxygen content, I'll service them with every visual and replace the burst disk every five years.

I have a few spare valves that so I'll usually just put in a fresh valve and then wait until I have a couple valves that need to be rebuilt before servicing them. I find that to be easier since once I have the cleaning and rebuilding parts out, the added time to rebuild multiple valves is miniscule.

 

[BoltSnap]

It is used and will do VCI and Hydro, do Tank valve service and replace burst disc with it too. I do the valve service with burst disc replacement with hydro service.

 

[tbone1004]

I've never understood why people insist on regulators being rebuilt on some arbitrary time cycle whether they need it or not, but not the valves. They use the same o-rings, use similar seats, and are exposed to the same environment. Personally I rebuild mine when the bottle goes in for hydro, and I rebuild my regulators around the same time or sooner if they ask for it.

 

[redacted]

I've never understood why people insist on regulators being rebuilt on some arbitrary time cycle whether they need it or not, but not the valves. They use the same o-rings, use similar seats, and are exposed to the same environment. Personally I rebuild mine when the bottle goes in for hydro, and I rebuild my regulators around the same time or sooner if they ask for it.

I don't understand why people insist on regulators being rebuilt on some arbitrary time cycle,