Shop drains tank before fill

[Divin'Papaw]

It used be thought that the cold water allowed fast fills by keeping the gas cold too. Tests and calculations show this is a minor positive effect, whereas water in your cylinder is a major negative effect. Good fill stations don't do this.

Except that it works.

I’ve been having my tanks frequently filled this way for 5 years now. It makes a difference.

The shop I use most often uses a cold water bath. They come out cold to the touch & are at 3600-3800 once they warm up. I’ve never had them get water in my tanks. The shop turns my tanks around typically in 20-30 min. 1000 psi to 3600 psi in 20 min consistently. I’ll take it.

 

[tursiops]

Except that it works.

I’ve been having my tanks frequently filled this way for 5 years now. It makes a difference.

The shop I use most often uses a cold water bath. They come out cold to the touch & are at 3600-3800 once they warm up. I’ve never had them get water in my tanks. The shop turns my tanks around typically in 20-30 min. 1000 psi to 3600 psi in 20 min consistently. I’ll take it.

Uhhh, OK. Fine.

 

[Tracy]

Doesn't fast draining freeze the valve and damage O-rings?

Why would freezing the valve damage Orings?

 

[Wibble]

Why would freezing the valve damage Orings?

Space shuttle demonstrated that.

 

[happy-diver]

are these damaged

 

[Gone for diving]

Can't feel them, one is slightly ratty,
But look deformed from incorrect clearance from machining, but looks like they where sealing fine.

 

[broncobowsher]

Those are used O-rings. Not freeze damage. Age formed into the machined space. Toss and install new, will be like that next time you take them apart.

The space shuttle O-rings were not damaged by freezing. But they were not sealing due to the cold temperatures. If they waited a few hours for them to warm up they would have been fine.

If freezing temps damage O-rings, we are in a world of hurt. So many things in the world are sealed by O-rings. And most of them operate in below freezing temps. They work just fine. Including countless scuba tanks stored in garages and trunks of cars that live in places where it is below freezing for months at a time.

 

[Gone for diving]

One place that orings tend to go bad. Is towmotor propane tank connection... they do get hard and cracky from the liquid propane, maybe cold, age, wear and tear.

 

[Pavao]

Except that it works.

I’ve been having my tanks frequently filled this way for 5 years now. It makes a difference.

The shop I use most often uses a cold water bath. They come out cold to the touch & are at 3600-3800 once they warm up. I’ve never had them get water in my tanks. The shop turns my tanks around typically in 20-30 min. 1000 psi to 3600 psi in 20 min consistently. I’ll take it.

Have you ever stoped to consider the reason you’re getting your tanks cool after fill is really due to the length of time it’s taking to get them filled rather than the effects of them being in water?

2600 psi in 20-30 minutes is a loooooooong time

 

[Divin'Papaw]

Have you ever stoped to consider the reason you’re getting your tanks cool after fill is really due to the length of time it’s taking to get them filled rather than the effects of them being in water?

2600 psi in 20-30 minutes is a loooooooong time

That’s from my arrival to departure. That includes unload, fill, test, load. Fill time if half that or less. The cold water bath absolutely makes a difference.