Getting HP Steel fills to rated pressure in South Florida area

[HowardE]

I didn't say they aren't doing it right. I said if they are filling to 4000 hot I am not taking my tanks there. And I stand by that statement. I don't give a rats *** HOW much technical gas their pumping. Cave Excursions pumped 5-10x as much gas and enjoyed a similarly stellar reputation. Shop still had a huge accident. It can happen.

But answer me this. If their fill rates are in compliance with PSI specs, And if they are not overpressuring tanks as per PSI recommendations, then how are they raising the pressure 500+ psi over spec on a fill?

Hot fills cool off. They don't make it policy to overfill tanks, AFAIK. If you're a good customer, and they've filled your tanks before, they may pump them up for you. My LP steel 72's they'll only fill hot to 2800 psi.

I don't think they'd be too worried about you not getting fills there... to each his own.

 

[PerroneFord]

Sure hot fills cool off. But I don't expect them to lose more than 500 psi in the cooling process. This indicates to me that they were filled too quickly.

I guess the difference between getting fills in S.FL. and N.FL. is that to get a good fill down there you have to be a "good customer". Here, every customer is treated the same unless given a reason not to be.

I've never filled at F.E. They may have a bang up operation. Good for them. If they do good fills for their customers, then that's also great. I never said I wouldn't take my tanks there. I said I wouldn't if my tanks see 4000psi on an intended 3442 fill.

When I fill my tanks to an intended 3200 psi, I see a MAX of 3280.

But as you say Howarde, to each his own.

 

[HowardE]

What does that mean they are filled too quickly - why is this so bad? You might not expect a 400-500 psi loss on a hot fill to water temperature, but it's true.

Everyone gets a good fill... Some people just get better fills than others

they do free top offs. So if you want them to fill to rated pressure... wait for cooling, then come back and get a top off - that's free.

 

[PerroneFord]

When you fill tanks quickly, the gas inside heats up. This gives you hot tanks, and a resultant increase in psi. As the tanks cool down to ambient temp, the pressure also goes down. The slower the fill, the less the gas in the tank gets heated.

Filling tanks hot is one of the top reasons tanks fail hydro, or lose their plus rating. Tanks lose their elasticity from repeated hot fills. So those who intend to keep their tanks in service and in spec for long periods of time, try very hard not to let them get filled hot.

We tend to fill at about 100-200psi per minute.. This is much slower than the recomended 300-600psi per minute that PSI says is allowable. However, we don't need to wait and top off. If I am trying to hit 3000psi cold in my AL80s, I shut the compressor off at 3075 or so.. and it backs down to about 2990 or 2995. No top off needed.

 

[BHB ScubaTroll]

I didn't say they aren't doing it right....

Actually, you did in a round-about way

Somebody down there has got to be doing it right.

 

[daniel f aleman]

PerroneFord

Fill Express has the best fill system in the country; you'd recognize it as so the second that you walked in to the shop. They bank all gasses.

 

[PerroneFord]

Actually, you did in a round-about way

That comment was in a DIRECT response to the original posters comment:



"Fill Express always fills them to around 3600 psi (final pressure after cool down). It's usually around 4000 psi hot."

400 PSI is a pretty fair drop. Not as bad as I was thinking from a target 3442psi, but it's still quite a bit. I imagine they have quite a lot of tanks to fill, and probably cannot afford to let a tank sit on the whip 30 minutes like some can. Ten minutes and out seems to be the norm. AL80 out in 5-10 minutes. Slightly longer for the HP tanks.

Fair enough. I'm sure they aren't hurtin for business.

 

[BHB ScubaTroll]

PerroneFord, you seem to make some assumptions as statements of fact...

Sure hot fills cool off. But I don't expect them to lose more than 500 psi in the cooling process. This indicates to me that they were filled too quickly.

Not necessarily true. But, at times it can be

I guess the difference between getting fills in S.FL. and N.FL. is that to get a good fill down there you have to be a "good customer". Here, every customer is treated the same unless given a reason not to be.

How would you know... unless you work for LDS... and then, you would not be objective about service.

 

[BHB ScubaTroll]

... We tend to fill at about 100-200psi per minute.. This is much slower than the recomended 300-600psi per minute that PSI says is allowable. However, we don't need to wait and top off. If I am trying to hit 3000psi cold in my AL80s, I shut the compressor off at 3075 or so.. and it backs down to about 2990 or 2995. No top off needed.

And, it took you 20-30 minutes to fill one-four tanks. That may cut it in your area, but not in busy areas.

 

[deepstops]

Cave Excursions pumped 5-10x as much gas and enjoyed a similarly stellar reputation. Shop still had a huge accident. It can happen.

But answer me this. If their fill rates are in compliance with PSI specs, And if they are not overpressuring tanks as per PSI recommendations, then how are they raising the pressure 500+ psi over spec on a fill?

First of all, what does the accident at CE have to do with this thread? The only firm "conclusion" I ever saw written up was from Luxfer stating someone was attempting to fill an unclean tank and that their tank wasn't responsible for what happened.
And attempting is correct verbiage because the fill whip hadn't been turned on yet from everything I ever read. The poor lady connected the fill whip and was about to turn it on when the little Luxfer 30 fell over, a hissing sound was heard, and then an explosion and flash fire occurred. This all happened with a tank containing about 1000 psi of O2 so where does that play into this thread??

PSI states fill rates of 300-600 psi/min are fine provided the final fill pressure is "correct" at 70f/21c. It's not any different than when I take my tanks to work in the trunk of my car when I'm going straight from work to a night dive. They get warm (maybe 120-130 if it's real hot) and read about 3900. Is that bad for my tanks?? Of course not. Otherwise I wouldn't see all the gas suppliers driving aroung with green O2 tanks in the back of their stake trucks soaking up the beautiful sun