Some Assmebly Required

[SpyderTek]

Originally posted by NetDoc

BTW, tanks do not ship from the factory with an EOI (Evidence of Inspection) sticker, so make sure your shop deals with that as well.

Yeah they did thanks. They put the sticker on the tank while I was there watching. The thing that made me feel a little anxious was the fact that they put it on the very bottom of the tank and I plan to put a boot on it.

Do boots come off easy? Or amI going to be having a heck of a time taking off the boot to show a new shop the sticker every time I want a fill?

Yes, the valve has an O-ring at the base of the threads. It looks like a simple rubber O-ring about an 1/8th inch thick. I don't see how, with this o-ring here, I can get it "Metal to metal" as you descibe Doc.

Additionally, no sort of grease came with the purchace. Is it totally needed? Or just something you want for extra protection?

Lastly, The tank itself came in a plastic bag, inside a box and the "hole" in the top of the tank has a very tightly seated plastic / rubber cork. Getting to a dive shop any time soon for a fill (and or assembly) is very difficult for me as I dont have a car to transport it. Therefore, if this tank has been siting in "wharehouse" for months sealed in this manner is it going to be better or worse for me to crack the plastic cork and assemble it with no grease and no positive pressure or should I just let it sit unassembled and corked till I can get to the shop?

Thanks for all the info guys!

SpyderTek

 

[MikeFerrara]

The problem with putting it on yourself is that if you bring it to a fill station completely empty they should insist on another visual before filling. An empty tank could have water in it. When we order tanks they always come with the valve off. before we sell it we do a visual, put the valve on and fill the tank. A shop may or may not include the cost of the visual and fill.

 

[The Chairman]

wait as long as I possibly could before I slapped the valve on that bad boy... which might be an hour or so :tease: I just love new toys!!! If your tank is in AC then there will probably be very little moisture to begin with.

When you do remove the "cork" you will find that there is a recessed area around the shoulder of neck for the O-Ring to sit in. If you put the O-Ring in without the valve, you will see that it sticks up just a tad above the shoulder top. This eliminates O-Ring extrusion at such high pressures.

Using Dow 111 (or equivelent) on the threads is more than just a good idea. Your cylinder is Al, your valve is a chrome plated brass and you will be immersing this concoction into a salt solution... Electrolosis will ensue and the valve will become part of the tank. Use the Dow 111 lightly on the threads and not on the O-Ring. This will keep the threads from seizing and the lack of lubricant on the O-Ring will also help to keep it from extruding. It was designed to be a static O-Ring, lets keep it that way.

BTW, most boots are open on the bottom... so you can see the EOI sticker there easily. If they put it on the side of the tank really close to the bottom, then the sticker will probably come off with the boot. Don't sweat it; just get a new sticker. Boots go on a LOT easier than they come off. Be sure to use the wood handle of a hammer and not the metal end when removing it too. Be patient and just work it off gradually. One good ding, and your tank won't pass it's annual inspection.

 

[SpyderTek]

Thanks Mike. I think that answers my question. No point in putting it together if they are only going to take it apart again.

ST

 

[roakey]

Originally posted by SpyderTek
Lastly, The tank itself came in a plastic bag, inside a box and the "hole" in the top of the tank has a very tightly seated plastic / rubber cork

Are you telling us that the shop put a VCI sticker on the cylinder WITHOUT even a CURSORY glance inside?

If so, here's the list of what your shop has done wrong:

Didn't assemble the cylinder and valve for you
Didn't give you a fill
Didn't inspect the cylinder, but put an inspection sticker anyway
Didn't put the sticker in the side of the cylinder where it belongs

You need to run, not walk away from this LDS as quickly as possible.

The Internet isn't the threat to LDS's, the LDS's are the threats themselves with customer service like this!

Originally posted by SpyderTek
Yes, the valve has an O-ring at the base of the threads. It looks like a simple rubber O-ring about an 1/8th inch thick. I don't see how, with this o-ring here, I can get it "Metal to metal" as you descibe Doc.

The outside points of the valve "nut" at the base will sometimes contact the cylinder outside of the O-ring groove, but not always. This is why I disagree with NetDoc's (and devjr) statement that you want metal-to-metal contact. On some cylinders, like my old PST 72 with 3/4" threads the valve can be tightened by hand down to metal-to-metal contact because of the deep O-Ring groove. On my newer Luxfer's the O-ring groove is shallow enough that there's no way you'll get metal-to-metal contact unless you crush the snot out of the O-Ring, which is detrimental to the O-ring as you might imagine.

O-rings seal by capture and are assisted by pre-loading. Pre-loading does not mean pre-crushing. As long as you tighten the valve down enough to capture the O-ring it will seal. You don't need to crush the ring. The pressure you exert on the ring by hand will pre-load load it so it seals correctly.

Roak

 

[devjr]

Netdoc is right about the lube. Furthermore, if anyone doesn't believe the manufacturer's torque requirements, then hear this: Go ahead and hand tighten a valve. Using a wrench I can turn that same valve at least another 1/8 inch. What does that mean?

It means that torque is required to squeeze the air out from under the valve flange. Otherwise, you are setting up a corrosion cell.

The size of the O ring groove and thickness of the ring are predetermined by the manufacturer to seal reliably when specified torque is used. Without a torque wrench, metal to metal snug and firm is good enough.

 

[devjr]

Spider, if the boot is hard to remove, try soaking the tank's bottom in a bucket of hot water.

 

[SpyderTek]

Well I put the boot and tank protector on. No need to remove the boot as the sticker is clearly visable through the opening in the bottom of the boot.

With regard to them slapping a sticker on it without even loking inside, the tank was manufactured this month as per the metal stamp located around the "neck" of the tank. I know that doesn't mean 100% it is defect free but it does say something.

As far as the rest of the stuff the I didnt ahve done at my LDS I consider it solely my fault. I wasn't thinking as I was so excited about my new purchases (the tank wasnt the only thing I got). I am sure they would have been happy to do all the "extras" had I just asked. In fact they even state "Test equipment & assembly - No Extra Charge".

All this would be moot if I just had my own car! Hehehe then I could take it back into the city to the place I bought it easily and they'd be happy to do it all for me. Sigh. Guess this was a learning experience.

It does bring up the issue however of buying a tank from E-bay or any other source in which you are going to have it shipped to you. In that case it will always come the way I got mine, unassembled and airless.

SpyderTek

 

[roakey]

Originally posted by devjr
Furthermore, if anyone doesn't believe the manufacturer's torque requirements, then hear this: Go ahead and hand tighten a valve. Using a wrench I can turn that same valve at least another 1/8 inch. What does that mean?

Furthermore, if anyone believes the devjr's torque requirements, then hear this: Go ahead and wrench tighten a valve. Using a hydraulic press I can turn that same valve at least another 1/8 inch. What does that mean?

It means that either one of us can turn the valve a little further, nothing more.

How much more you can turn a valve depending on which tool you use means absolutely nothing.

Roak

 

[roakey]

Originally posted by SpyderTek
With regard to them slapping a sticker on it without even loking inside, the tank was manufactured this month as per the metal stamp located around the "neck" of the tank. I know that doesn't mean 100% it is defect free but it does say something.

In the PSI class you get to see a cylinder shipped from Luxfer that had a fold in the shoulder/neck area that was so pronounced that it only left 3 or so threads intact.

Very scary defect.

Roak