Question regarding tank fills

[Scraps]

Whether it’s because of their technique or the limits of their compressor, you’re not getting what you’re paying for.

If they can’t or won’t deliver cool tanks filled at least to the rated pressure, go elsewhere for all your business.

If a shop won’t deliver fair value on something you can easily verify, would you expect them to deliver fair value on regulator servicing, which is much harder for you to check?

 

[DallasNewbie]

Dumb newbie question, but what would be the shop's motive in deliberately short filling? Is it just time consuming to get to the right pressure, or is there a greater cost, e.g. electricity, in getting the pressure up?

 

[rob.mwpropane]

Dumb newbie question, but what would be the shop's motive in deliberately short filling? Is it just time consuming to get to the right pressure, or is there a greater cost, e.g. electricity, in getting the pressure up?

Lazy, wear and tear on the compressor,.. but mostly lazy.

 

[Divin'Papaw]

Dumb newbie question, but what would be the shop's motive in deliberately short filling? Is it just time consuming to get to the right pressure, or is there a greater cost, e.g. electricity, in getting the pressure up?

Laziness, having an underpowered compressor, not having high pressure bank cylinders … but typically it’s just laziness and lousy customer service. They want to give you as little as they can get away with as opposed to what any diver expects … tanks filled to their fill capacity.

 

[MaxE]

Hi, all, as the title suggests, I have a question regarding the tank fills at my LDS. I have a steel 100 tank that I use all but exclusively.

As far as I understand, the shop does a sort of quick fill method; they overpressurize the tank, and then cool the tank in water so that, when cool, it should be at the rated pressure of the tank, either 3000 for their 80s, or 3442 for my 100.

I've never had it filled to 3442 psi; I think the closest I ever came was 3000. I had a yearly visual done on the tank a few weeks ago, and when the tank was filled afterward, my SPG showed a pressure of 2500. I felt a little ripped off, but I didn't mention it to the LDS because it had been a couple of weeks since the fill that I went diving, and I'm not really sure I understand enough about the fill process to make an educated complaint.

This afternoon, I got another fill at the LDS for a dive planned for tomorrow. I just put the SPG on the tank, and it's showing a pressure of 2200. Am I right in thinking that something's wrong in this situation? I get it that pressure drops as the air cools, but it shouldn't drop that much, right? Am I missing something?

(I do plan on asking them if I can use one of their full tanks to check and make sure that it's not my SPG, but I thought I'd start here in the meantime)

If your constantly getting fills at 2400 psi it makes me wonder if your 100 is a LP tank or if the shop thinks it’s an LP tank…. What do all the marking on the tank say? Is there a “+” anywhere?

 

[Degenerate]

What you are getting is a hot fill. They pump it up over the target pressure and hand it back to you. When it cools off (compression of air creates heat) the tank should be close to its rated pressure. It Doesn’t usually work that way and you get a short fill.

That is how a hot fill is supposed to work, but...
There is no way the shop filled OPs tank to more (or even remotely close to) the service pressure of 3442psi if he ended up with 2200psi cold.
OP didn't get a hot fill, he got what we call a "b*tch fill", it's really annoying and definitely a cause to fill at a different shop if they won't top it up for you.
I suppose this is one of the reasons people in the US prefer LP tanks.

 

[Bob DBF]

I had a similar issue with a shop some time ago. I determined that the shop owner/manager would give a good fill, but the tank monkeys gave fills all over the place, mostly low. They were hot fills and coming back to top off used an hour in the wrong direction from the dive.

I came back to refill with all the previous tank pressures, good and bad, with the names of the monkey, if I knew. Within a few months I was getting reliably good fills, occasionally low, but nothing that would change the dive plan. It was a matter of bringing it to the managers attention and better training of the staff. Since no one else brought it to their attention, nothing was done.

 

[CT-Rich]

The shop I use has a gauge out front and I conspicuously check each tank when I pick it up. They know me and my tanks and seldom get short fills once I started doing that. Trust but verify.

 

[DogDiver]

24/7 self serv fills.

 

[boulderjohn]

There is absolutely no conceivably good explanation for an HP 100 to get filled to only 2200 or 2400, and you should point that out immediately. If they don't immediately take care of it with a sincere apology, you need to go to a different shop.

As for fills to 3,000, there might be an explanation, but it still isn't good. If I just dropped my HP tanks off at the shop where I get fills and left, they could easily be filled to only 3,000. That would be because mine are the only HP tanks she shop ever fills, and it has a governor on the filling that stops it at 3,200 so it will cool to 3,000. If whoever fills tanks does not realize mine are different, I will get a 3,000 fill. They have to take that governor off for me to get a proper fill.