Moisture getting into the tank - Just wondering!

[Topbodz]

A couple days ago, I took two tanks to my "Ex lds" to fill.

The lds refuse to fill them unless he did a new vip because they were empty.

I explained to them that the tanks had just been Hydroed & VIPed that day.

but still he wanted to do a VIP at $10.00 a pop...

I told them where to go.... & stormed out...


The manager called later to defend the rep, by saying that there
could of been moisture in the tank which may cause it to blow up.... blah blah....

So just for curiosity:

The tanks were just hydroed & VIPed... Of course they were dried on a tank dryer & the valves replaced & torked
the valves were closed.... so now can anyone tell me just how moisture would get into the tank.

Tell me all the possible ways moisture gets into a tank, even if its been sitting for a month or so....


btw: I took them to another lds and he didn't even check to see if they had air... he just filled them...




thanks

 

[Scared Silly]

Because the cylinders were empty the dive shop was totally within reason to want to look inside regardless of what you might have told them. However, given what you said and if indeed the there was proof of a new VIP then a reasonable shop would have taken a quick peak before filling without charging you.

My question is why did they just get a VIP but were not under pressure? If you are doing your own VIPs it behoove you to get a transfill whip so that you can put them under pressure after the inspection. If the VIP was done at a hydro facility then it would be still be reasonable to take a peek because it is possible that at some point the valve could have been turn on without you knowing it.

 

[Topbodz]

Because the cylinders were empty the dive shop was totally within reason to want to look inside regardless of what you might have told them. However, given what you said and if indeed the there was proof of a new VIP then a reasonable shop would have taken a quick peak before filling without charging you.

My question is why did they just get a VIP but were not under pressure? If you are doing your own VIPs it behoove you to get a transfill whip so that you can put them under pressure after the inspection. If the VIP was done at a hydro facility then it would be still be reasonable to take a peek because it is possible that at some point the valve could have been turn on without you knowing it.

That's what I thought. just take a peek inside & fill the damn thing..... so, IF the valve had been left open HOW much moisture could have gotten in there? I've opened thanks that hade been empty for a while and they were "clean as a whistle"... just wondering..... are people make this a Big deal where it needs not be?

 

[captain]

What are you going to see. Can't see moisture in the air. We know it here but we can't see it. We can do wet bulb test to determine what the % relative humidity is.
Unless there is liquid water in the tank taking a peek serves no purpose. Even if the valve was left open the moisture in the tank would be no greater than outside the tank.
When will the tank insanity stop.

 

[Wookie]

Just curious. Did you take the cylinders to the hydro facility yourself? I do it all the time, but then I own hundreds of cylinders. Your Ex-LDS may feel that you cut them out of 20 bucks profit. And so you did. And you voted with your feet. Is there any VIP sticker on your cylinder? Hydro facilities typically don't put one on, because they are silly. Most dive shops want one, because they want to sell you a 20 dollar sticker.

 

[duckbill]

Surface, or "immersion" rust is harmless. Cylinders often end up with a light coat during the drying following a hydro. I am finding that some LDS operators don't really know how to do a visual, so they take the safe way out and fail it if they see any rust. A qualified inspector should be able to spot a true problem rust pit in spite of an smooth orange coat of surface rust, or even bloom, it just takes more doing than Joe Blow LDS op is either trained to do or is not too lazy to do. My LDS wants it spotless, no orange whatsoever. Hell, any untrained and unskilled cat can inspect and pass tanks by those standards.

 

[bletso]

It really depends on atmospheric conditions. I had a customer once who took two cylinders for hydro and left them in the boot of his car for a week with no valve. He must have had a couple of tablespoons of water in steel cylinders. It cost him more to clean them up than the hydro. If it was hydro tested and valved properly then there should have been no issue. We hydro commercial cylinders all the time and when they are filled they have to have less than 2 ppm moisture content. Our customer never has issues, well at least from us. Just ambient moist air at 1 atm will cause a cylinder to fail moisture content when filled to 2015 psi

Dale
Engineered Inspection Systems, Inc. Home Page

 

[captain]

I had a cylinder I didn't plan on using but didn't want to get rid of. It sat without a valve for several years outside but under a roof. A friend asked if he could have it so I took a look inside before giving it to him. Guess what, It looked just like the day I put it there, light flash rust, no liquid water. It went to the hydro shop and passed.

 

[Topbodz]

Just curious. Did you take the cylinders to the hydro facility yourself? I do it all the time, but then I own hundreds of cylinders. Your Ex-LDS may feel that you cut them out of 20 bucks profit. And so you did. And you voted with your feet. Is there any VIP sticker on your cylinder? Hydro facilities typically don't put one on, because they are silly. Most dive shops want one, because they want to sell you a 20 dollar sticker.

Yes I did cut them out of $20.00. I buy & sell tanks and I've taken tons of tanks to them at $37.50 a pop until I found a Hydro shop to do it for me directly) They don't have to put a sticker, because the a formal VIP is part of the Hydro process, so technically for the year of the hydro, no sticker is needed, but they do put a sticker on the tanks for me... I found that some shops can't even read the dates on the stickers.... Anyway I think that a $5.00 fill is still better than nothing... I have my own compressor now, jut waiting for the air purity test, then I'll fill my own.....

 

[Topbodz]

It really depends on atmospheric conditions. I had a customer once who took two cylinders for hydro and left them in the boot of his car for a week with no valve. He must have had a couple of tablespoons of water in steel cylinders. It cost him more to clean them up than the hydro. If it was hydro tested and valved properly then there should have been no issue. We hydro commercial cylinders all the time and when they are filled they have to have less than 2 ppm moisture content. Our customer never has issues, well at least from us. Just ambient moist air at 1 atm will cause a cylinder to fail moisture content when filled to 2015 psi

Dale
Engineered Inspection Systems, Inc. Home Page

I just don't see how you could keep ambient moisture out of the tank between the drying of the tank & putting the valve on.
how do you guys do that.