"Industry Standards (US)" What are they?

[jIM STEELE]

 

[rjack321]

I don't know where you get yours tested but my shop uses clean tap water for each and every cylinder. We test thousands of cylinders a month. Engineered Inspection Systems, Inc. Home Page We treat steel scuba cylinder different than industrial cylinders as we use N2 to purge and dry them. We use no additives to steel cyls due to health concerns. N2 for drying is all it takes to prevent flash rust. Al cyls are dried with hyper filtered air. If O2 service they are cleaned for O2 service after hydro.

I have not seen them refill the pressure vessel in between cylinders. In fact whatever is on the outside of a cylinder ends up in the water jacket - which doesn't directly mix with the interior water but its not well separated either. But I note that you are cleaning cylinders for O2 service after hydro despite using "clean" water. That was really my point, that just because the test water isn't intentionally contaminated doesn't mean an O2 cylinder has remained clean enough.

 

[NAM001]

as soon as water in in the tank it is no longer o2 clean.

 

[bletso]

I have not seen them refill the pressure vessel in between cylinders. In fact whatever is on the outside of a cylinder ends up in the water jacket - which doesn't directly mix with the interior water but its not well separated either. But I note that you are cleaning cylinders for O2 service after hydro despite using "clean" water. That was really my point, that just because the test water isn't intentionally contaminated doesn't mean an O2 cylinder has remained clean enough.

You obviously aren't familiar with the hydro process. After the cylinder is filled with water, a test adapter is put in the cylinder in place of the valve. The test head is lowed and connected to the adapter via a quick disconnect and the whole assembly is lowered into the test "jacket". The test is performed and the assembly is removed from the jacket. The less than clean "jacket water" never enters the cylinder. The water pumped into the cylinder is filtered mains supplied through a high pressure piston pump. The water jacket water is continually changed whilst testing various size cylinders. Also greasy cylinders are de-contaminated prior to testing. It is a separate operation and the customer pays a premium for it.

The adapter is removed and the cylinder is the purged, heated, dried, stamped and valved.

The biggest problem in O2 cylinders is not what is inside them. They often are very less than "SCUBA clean". BUT, industrial O2 cylinders are seldom hydro-carbon contaminated internally as the cryogenic pump and evaps are all O2 clean and lubed. However, SCUBA cyls are prone to this problem due to the lube oil from the compressors we use, hence the very cautious approach from our industry as regards O2 service.

Most industrial operations will NOT fill O2 cylinders with a hydrocarbon sheen on the outside of the cylinder or valve. It is a common problem with shop monkeys spraying WD40 or equivalent on the "stuck" cap.

 

[ktomlinson]

You obviously aren't familiar with the hydro process. After the cylinder is filled with water, a test adapter is put in the cylinder in place of the valve. The test head is lowed and connected to the adapter via a quick disconnect and the whole assembly is lowered into the test "jacket". The test is performed and the assembly is removed from the jacket. The less than clean "jacket water" never enters the cylinder. The water pumped into the cylinder is filtered mains supplied through a high pressure piston pump. The water jacket water is continually changed whilst testing various size cylinders. Also greasy cylinders are de-contaminated prior to testing. It is a separate operation and the customer pays a premium for it.

The adapter is removed and the cylinder is the purged, heated, dried, stamped and valved.

The biggest problem in O2 cylinders is not what is inside them. They often are very less than "SCUBA clean". BUT, industrial O2 cylinders are seldom hydro-carbon contaminated internally as the cryogenic pump and evaps are all O2 clean and lubed. However, SCUBA cyls are prone to this problem due to the lube oil from the compressors we use, hence the very cautious approach from our industry as regards O2 service.

Most industrial operations will NOT fill O2 cylinders with a hydrocarbon sheen on the outside of the cylinder or valve. It is a common problem with shop monkeys spraying WD40 or equivalent on the "stuck" cap.

If we were all so lucky....when I got my tanks back from hydro the last time they were full of rusty gunk that wasn't there before.

 

[Colliam7]

Part of my motivation for this thread was that I ran into a new "industry standard" a while back - at least that was the claim. I was told by a dive operator that I would not be able to bring my pony tank on the boat because it did not have a current VIS sticker. The tank was full (and in hydro - not that that should matter) and I had no expectation that the operator would fill the tank. Anybody else ever run into this?

There may be advantages to teaching through a dive shop. To paraphrase some Dire Straits lyrics, 'Work for nothin' and VIP stickers for free'. OK, doesn't have quite the same cadence, but it does apply.