problem with Thermo K valves

[barracuda]

hi folks !!

been having a small leakage problem with our Thermo K valves which are just used for 6 months. after we serviced the same, they hold a full charge but when connected to the regulator, they leak from the on/off valve after the tank is turned on.

my guess is that the problem is either with the brass washer or the teflon washer(s). anyone out there who is 100% sure ? a quick reply would be appreciated as we need to order the parts required from abroad. thanks and regards.

venkat
barracuda diving india

 

[LUBOLD8431]

If it was the brass washer, they would be leaking all the time. If its only when you turn the valve on, then there is not a seal around the stem. So, yes, it most likely is the teflon...

Good Luck...

 

[Genesis]

With them turned off you can (if you're careful!) remove the entire packing/bonnet nut and washers without leaking, because the seal is made by the seat.

Its ALMOST CERTAINLY the crush washer, and some idiot probably reused it. That's a no-no. You can try to tighten the top nut down a bit, but BE CAREFUL doing it, because that is a brass valve you're screwing with and if you overtighten it you'll either gall it and never get it apart again, or strip it out entirely in which case you've got a trashed valve.

The correct fix is to disassemble the valve and replace the crush washer.

To know FOR SURE where its leaking, remove the handwheel nut, put a reg on the valve, turn it on and then submerge it in a bucket. You can then see where its leaking from.

BTW this design sucks, but Thermos in general are great valves. Genesis has a double-O-ring bonnet seal which is much better in this regard and does not depend on a crush washer.

 

[LUBOLD8431]

yeah, Karl is right on that...

You might want to rebuild it again...

Maybe its not tightened enough on the washer... or the washer is junk, and needs to be replaced, or it still COULD be the teflon. Either way, you need to get back in there, and check it out...

 

[barracuda]

many thanks for your replies. appreciate it. will get on to the job and try to sort it out.

have been taking apart the valve without emptying it (carefully) and checking and cleaning the parts all over again so far. regards.

venkat

 

[barracuda]

one more question !! how often is it recommended to take apart the valves to service them ? we only use our tanks 6 months a year (everyday). i keep getting different answers to this !!

venkat

 

[Genesis]

and you aren't using them in high-FO2 service (e.g. partial pressure blending Nitrox) leave them alone!

If you ARE PP blending, then I'd take them apart annually, simply because they accumulate "stuff" inside (they're the "orifice" on the tank, so things tend to deposit on the workings) and when there IS an incident with a high FO2 tank, its usually the valve that it happens to/inside.