All about cylinder inspections & training

[Ben_ca]

Hello Gang,
Went to LDS Wednesday to fill my tank... dropped off... Later the owner says to me that VIP is overdue.. (the sticker says July 04. The next day he says there's a problem... rust in tank. Arghhh.. I know about flash rust... but anyway he says must be tumbled... I know about supporting your local LDS but this is getting rediculous. It's like bringin your car to the shop... I'm seriously thinking about switching shops. A few questions for the smart people out there.

1. Isn't VIP good till the end of the month?

2. How often have you had to get your tansk tumbled?
(mine were wet about 10-15 times this year about 5 times in salt.... rinsed and washed... never below 500 psi)

3. How often do tanks fail VIP?

4. SO far I'm up to 15 for VIP 20 for tumble clean (his assistant wanted to charge 40)

 

[miketsp]

1. Isn't VIP good till the end of the month?

A cylinder may be requalified at any time during or before the month and year that the requalification is due.

Print the DOT regs and show the LDS

From DOT regs:
http://hazmat.dot.gov/regs/180.205.htm

 

[Ben_ca]

A cylinder may be requalified at any time during or before the month and year that the requalification is due.

Print the DOT regs and show the LDS

From DOT regs:
http://hazmat.dot.gov/regs/180.205.htm

This really pisses me off... I could have gotten my weekend dives in and then had them VIP'd... I think he was waiting for me to rent tanks from him too. I'm seriously thinking of bringing my business elsewhere.

 

[swim2mi]

My LDS has always allowed a tank to go to the end of the month it was due. I don't know the exact regulations. Sorry about the rust problems. It seems there is always something in this sport to suck a few more dollars out of you.

 

[Ben_ca]

My LDS has always allowed a tank to go to the end of the month it was due. I don't know the exact regulations. Sorry about the rust problems. It seems there is always something in this sport to suck a few more dollars out of you.

I would have been more receptive if he would have said... "Ya know your VIP is up at the end of the month... Drop it by after teh weekend and we'll get 'er done". I'm going to drop my other tank of at the other dive store (45 min drive) and see how they treat me.

 

[Scuba_John]

Question, are your tanks steel? Alum does not rust as far as I know. Sometime a flakie white substance but never rust.

 

[RichLockyer]

I would have been more receptive if he would have said... "Ya know your VIP is up at the end of the month... Drop it by after teh weekend and we'll get 'er done". I'm going to drop my other tank of at the other dive store (45 min drive) and see how they treat me.

Before you pay them to tumble them, take a look at them yourself and see if Dave Dalton's "DFRED" device can save them. If that's the case, then you can take care of them yourself for about $3 and an hour or less of time. Pop the valve back in and off to a different LDS for the vis.

 

[Drew Sailbum]

49CFR180.205 discusses regulations governing the hydrostatic testing of cylinders. There are currently no authoritative governmental regulations regarding visual inspection of cylinders (excepting composite hoop-wrapped construction). This code does specify that a visual must take place with a hydro, but does not require that a VIP be performed nor that a visual be performed except with a hydro (usually every 5 years in USA.

During my PSI cylinder inspection training, I was taught that a visual inspection expires one year from the date it was performed. If the exact date is not known, then it is presumed to be the first day of the marked month.

VIP is a specific test used to look for cracks in the cylinder neck of 6351 alloy aluminum cylinders. This test has absolutely no validity or use in steel cylinders and the machines used to perform these tests are not designed to work in steels. The usefulness of this test is uncertain in 6061 aluminum alloy cylinders.

As to how often cylinders fail visual... I have failed two this year out of 138 examined. Both were about 2 years since last hydro. One had salt water inside which generated significant corrosion of the threads. The other had a crack through two threads in the neck. I have about 60 more left to look at and if this pace holds there might be one more.

Rust can (and will) occur in steel cylinders in the presence of water. Water can get inside cylinders in several ways.

• Water can seep in around the neck o-ring if the tank is run dry and left to sit in water.

• Water can be blown in through a fill whip using poor technique. This is not entirely uncommon if filling occurs in a water bath.

• Water can leak in through the valve opening if the cylinder is submerged while empty. Again this sometimes occurs if an empty cylinder tips over in a water bath.

• Water can be blown in with the compressed air if the filter stacks are not adequately drying the compressed air.

 

[rickyd]

Before you pay them to tumble them, take a look at them yourself and see if Dave Dalton's "DFRED" device can save them. If that's the case, then you can take care of them yourself for about $3 and an hour or less of time. Pop the valve back in and off to a different LDS for the vis.

OK, I've done the searches, and can't find anything on DFRED. Even when to Dave's web site and looked......so, what the heck is a DFRED?

 

[RichLockyer]

OK, I've done the searches, and can't find anything on DFRED. Even when to Dave's web site and looked......so, what the heck is a DFRED?

Oops... different message board. Check the DIY section on http://thescubastop.com/
Basically, it's a 1/8" brass rod with a handful of 12" weed-whacker lines hoseclamed to the bottom and spun un a hand drill. You can also use stainless cable.
El-Cheapo tank whip. If the whip doesn't clean the tank, then it DOES need a tumble. Some shops ignore the simplicity of the whip and immediately write up a tumble.

DFRED = Dalton Flash Rust Elimination Device
Yet another in a series of affordable pieces of Scuba Equipment from Dalton Enterprises