Pressurized air bottle valve?

If you know the diameter and threads per inch or pitch for metric you can look up a table for that particular thread size. Then use a crows foot socket on a torque wrench to tighten to proper torque. Then air it up a few hundred pounds and leak test with soapy water. If you see no newly formed bubbles you are good to go. Filler up. MM

When I put my valves back in (after removing to check for moisture) I basically crank them as hard as I can with hand pressure. That's all. The o-ring is what does the sealing.

I think that "warning" is there for legal precaution in our litigious society.

I just checked the manual that came with my Air Venturi 74 cubic foot CF tank. It said if you need to remove the valve: FIRST BE SURE IT IS EMPTY, then:

"The Valve Body (B) is only hand tightened into the Cylinder (I). To remove the valve, begin by orienting the valve away from your body, other people and any objects in the area".

So I would put a little silicone grease on the O ring and tighten it as tight as I could using hand pressure only. It's not like it's going to fly off unless you have it cross threaded or the threads are not the right size. Test with soapy water and if there is a leak, tighten it a little more.

P.S. You can read the manual on the 74' CF tank on Pyramid Airs website, if you want more info.

Hand tight is usually sufficient. Really, just tighten by hand and if the o-ring groove is metal to metal, you're good to go (the bottom ring of the valve is in 360 degree contact with the upper lip of the tank). Anything further than that serves no purpose. The o-ring compressed in the groove is what provides the sealing...So hand tight, unless you can't get the metal to metal contact, then put a wrench on it and give it a little turn until you have proper compression of the joint. It shouldn't take much.

Just got an email from the Acecare group

they said to tighten the valve to 80-100Nm

seems VERY strange to me. Normally you have a specific torgue not from this to that.

im a mechanic specializing in machinery so I know a bit about tightening stuff to a specific torque. AND how dangerous it can be if you overtight or not tightening enough.

so Now im scratching my head what to do.

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As previous posts have said, hand tight is all that’s necessary. Disregard torque numbers. Add silicone grease to the valve threads and hand tighten it. Tanks seal on the O-ring. Once the valve is pressurized it is locked on tight. You couldn’t loosen it under pressure if you tried.

Please note there is no way to secure the tank with a wrench . No hex or flat. If you have ever had to remove a tank valve, securing the tank from turning can be very challenging. The last time I did that, I strapped the tank with cargo straps to a forklift fork. As others have said hand tightening is just fine.