Valve Stuck On Al80 Tank

[bhapps24]

Just got my tank back from other lds. thay put on new genisis k valve VIP and fill for $60.00. The tank checked out ok. I hope that doesn't happen again. Have a great 4th of july all.

 

[Braunbehrens]

pescador775 once bubbled...
A tank valve is no different from thousands of other O ring designs for various connectors and bulkhead fittings.

I was under the impression that O-rings are usually used as a pressure seal, but in the case of the tank to valve connection the o-ring is used as a compression seal.

In other words, O-rings usually do not depend on a tight connection to hold the pressure, but rather on an ingenious design that uses the pressure itself to exapand the O-ring slightly which makes the seal. In the case of the Valve, the O-ring is actually simply compressed into a tight space which makes a seal. The same is true for the hose to 1st stage o-rings.

Is this wrong?

 

[FredT]

Braunbehrens: You got it correct.

rmediver2002: The Catalina torques are MAXIMUM values. I expect those are to limit damage to the aluminum threads and tank neck.

Hand tight, plus whatever is necessary to keep an unpressurized fitting from vibrating loose in service ar all that is necessary to maintain an SAE or 3/4" NPSM Oring sealed fitting. Naturally the "whatever is necessary" varies by application. For a Scuba cylinder it's "not much".

I tighten tanks by hand with an inertial bump. Feed the valve in within a turn or two of bottom, then lift and spin the tank. At the last second snap the valve the other way with your wrist. The momentum of the tank provides all the "extra" necesssary to maintain the seal, and the valve is easily removable with an 18" Crescent wrench at the next visual.

FT

 

[TeamZissou]

Din can easily be removed by threading in what is essentially a pipe with a 5/8 inch BSP thread. 24 inches should give you plenty of leverage. For Yoke valves, use a big (the bigger the better) adjustable wrench. I recommend using a thin rubber glove underneath the wrench to avoid marring the chrome. Place the wrench where is it not going to slip (sometimes higher on the valve than the hex at the base) and be sure it's very tight. Using either method, if it is still stuck, tap with a mallet or dead blow hammer. If that doesn't work, refer to the thread above.

 

[Schwob]

Din can easily be removed by threading in what is essentially a pipe with a 5/8 inch BSP thread. 24 inches should give you plenty of leverage. For Yoke valves, use a big (the bigger the better) adjustable wrench. I recommend using a thin rubber glove underneath the wrench to avoid marring the chrome. Place the wrench where is it not going to slip (sometimes higher on the valve than the hex at the base) and be sure it's very tight. Using either method, if it is still stuck, tap with a mallet or dead blow hammer. If that doesn't work, refer to the thread above.

Since you resurrected a 17 year old thread to say this ... and since I seem happy about another “non-pub” thread in these times:
So, I understand you are threading a pipe into where normally the regulator goes in a DIN valve and then use that pipe to apply the breaking torque. In that process, I would think that you could be putting undue stress onto the very weakest part of a DIN valve in a way that it surely was not designed for. If I knew anyone was doing that to my valves, I’d ask them to replace them with a new equivalent one and they can keep the one they tortured.
But you’re a pro, so maybe you know better and your method actually is endorsed by manufacturers of DIN valves. If so, I’d appreciate if you could link to the reference/s.

 

[broncobowsher]

He has a PADI pro card, that is all the endorsement he needs. Well proven by the fact that he took a thread that has been dead for longer than some of viewers have been alive and replied to it. I am sure there is a PADI dead thread revival specialty card that goes with his PADI Pro status.

 

[happy-diver]

 

[RogueClimber]

I do wonder if necroposting is covered

 

[TeamZissou]

Happy-Diver gets it. If your valves are being unduly stressed by inserting either a specialized tool or a 5/8 BSP 14TPI pipe (same thread anyway) you may have bigger problems than a stressed valve. See above. Nothing like a good COVID lock into revive a dead thread. Never know who may need it.

 

[Zef]

Since you resurrected a 17 year old thread to say this ... and since I seem happy about another “non-pub” thread in these times:
So, I understand you are threading a pipe into where normally the regulator goes in a DIN valve and then use that pipe to apply the breaking torque. In that process, I would think that you could be putting undue stress onto the very weakest part of a DIN valve in a way that it surely was not designed for. If I knew anyone was doing that to my valves, I’d ask them to replace them with a new equivalent one and they can keep the one they tortured.
But you’re a pro, so maybe you know better and your method actually is endorsed by manufacturers of DIN valves. If so, I’d appreciate if you could link to the reference/s.

First, you would be hard pressed to get a shop to give you a new valve in the scenario you describe unless you could show proof that they damaged it. In court it would most likely be tossed for lack of merit if you could not show that damage was done, and if you were to claim some impact on the metallurgy of the valve it would be on you, financially speaking, to have it tested/studied to prove that there was damage, and if there was none it would a sunk cost to you, and only possibly recoverable if asked for among the damages you seek to claim.

The scenario you present is quite possibly, along with liability issues, why customers are not allowed in service areas and why service areas are not often open to public specter...and I am not just referring to the SCUBA industry with this. Often times procedure or necessity requires a level of force or manual/mechanical manipulation not expected by the customer, and their knowledge of that force/manipulation, while largely immaterial to well being of the device, would create a sense, of shock, surprise, or worry in the mind of the customer and be bad for business.

In the case of the OP, where the shop rounded off a portion of the the valve with some sort of wrench, it could be argued that they were not using the correct tool or technique to remove the valve....they could counter that the valve and tank were not properly maintained before it was brought to them for service and the damage to the valve was therefore inevitable to remove and further inspect/service the tank. The fact that the OP took the tank with valve installed back from the shop and worked on it, and had his own wrench slip further causing damage, would both support the notion that the tank/valve were not properly maintained, and would provide issues with proving who damaged the valve. The reality is that it would be hard to prove that the shop damaged the valve with malicious intent so recovery by legal means would cost more in time, effort, and money for the OP than the cost of replacing the valve.

Second, a PADI professional level certification has nothing to do with shop procedures/being an expert on the actual specialized service/maintenance of equipment. PADI does not certify people as professionals for the purpose of doing specialized maintenance on SCUBA equipment. There is a PADI certification course for Equipment Specialist but, from my understanding, it is basic/general maintenance, care, and storage of common gear used in SCUBA diving. Here is an excerpt from PADI's brief description of the academic course content:

"You’ll learn about routine care and maintenance procedures as well as scuba equipment storage recommendations. Your instructor will show you how to overcome some common equipment problems and offer equipment configuration suggestions. You may even get to jump into the water to try new or unfamiliar equipment."

-Z