Just out of curosity what is the reasoning against "flash filling"?

[DevilMan]

^^^^Crazy, scary, stupid stuff eh?

its special cause you are special.

The FLASH fill that I saw... yeah it's not something I care to do nor have done to my tanks. But the more common lever pull, or button push that takes it a bit because the air flow is reduced... it makes the bottle warm, but hardly damaging I would guess.

DM

[vf-xx]

I agree. That is probably why HPA tanks have a 15 yr life. Flash filling does not provide higher pressures just more heat. It will cause the stress strain curve to be modified, but the next cycle should not change the curve. Once the work (I know thats not the term Im looking for) is done putting the same stress/strain will not hurt anything (assuming that you haven't already passed the maximum point).

Yes, but heat changes the physical properties of the material, and change can be dramatic over a small temperature range. Not saying it 'is' here, just that it can be. I don't have nearly enough hard data to run the numbers.

I agree with you here. I am just not sure that heat is that high. After all firefighters use carbon fiber HPA tanks, and they are exposed to higher heats than we put on our tanks.

Not sure that this is a valid argument. Do Firefighters use the same tank into high temp multiple times a day, for weeks on end? Also, do Firefighter's SCBA's run at 4.5k? I know SCUBA only runs at 2200. I honestly don't know the answers to these questions.

I agree, but it is impossible to instantaneously fill a tank. I am not sure what is the fastest that you can fill a tank from empty to full (on a 4500psi system), but I would think it would take at least 20 seconds. I am not sure if that is considered "sudden"

While true, but I don't think that the regulator system is perfect, given throttling, temperature issues, and valving, I could see pressure spikes above 4500. They wouldn't last long, but I could see it.

[caylegeorge]

I don't believe this is entirely correct. The warming of the bottle is also from the expansion of the bottle its self.

... The warming of the bottle is only from the compression of the air that was in the tank before the fill.

[Spider-TW]

Not sure that this is a valid argument. Do Firefighters use the same tank into high temp multiple times a day, for weeks on end? Also, do Firefighter's SCBA's run at 4.5k? I know SCUBA only runs at 2200. I honestly don't know the answers to these questions.

I would expect firefighter SCBA tanks to be fiber glass and a specialized resin for the temperature. Fiber glass is not as strong, but twice or more of the melting/degradation temperature of kevlar. Not features you would normally warranty against, except when the kids want to set their markers on fire.

Does the American Composite Manufacturers Association publish any standards?

[nerobro]

I don't believe this is entirely correct. The warming of the bottle is also from the expansion of the bottle its self.

Cycling the material of the bottle, once, for all of a couple fractions of an inch, will not produce any discernible heat.

[DevilMan]

I agree, but it is impossible to instantaneously fill a tank. I am not sure what is the fastest that you can fill a tank from empty to full (on a 4500psi system), but I would think it would take at least 20 seconds. I am not sure if that is considered "sudden"

This isn't true. There are places that can fill a tank in about 1 second. 2 tops. I'm not kidding. Until you find a place that actually does it, you'll more than likely not believe me, but I've seen it done.

DM

[nerobro]

This isn't true. There are places that can fill a tank in about 1 second. 2 tops. I'm not kidding. Until you find a place that actually does it, you'll more than likely not believe me, but I've seen it done.

DM

read: why push button fill stations scare Nerobro.

Ever seen what happens when a fill whip popps off with 4500psi behind it? Screw the tank, I don't wanna get hit with the flail!

[athomas]

read: why push button fill stations scare Nerobro.

Ever seen what happens when a fill whip popps off with 4500psi behind it? Screw the tank, I don't wanna get hit with the flail!

I have a friend that got hit in the finger with one. He ended up with a broken bone in his finger. And that was with 3000psi, not 4500.

[nerobro]

They used to enforce some really good rules at fill stations. They don't anymore. :-( Heck, some places like CPX.. you can't even position the gun properly to hold the whip and be out of the way of a failure.

CPX even used to have a fill station that was rigid, that you hung your gun off of when they filled groups of tanks at once. *shivers*

[MANN]

This isn't true. There are places that can fill a tank in about 1 second. 2 tops. I'm not kidding. Until you find a place that actually does it, you'll more than likely not believe me, but I've seen it done.

DM

wow. I have never seen one fill that quickly. I thought the 20-30 seconds was fast. Maybe that is why my tank is not getting that hot.

[Beemer]

Maybe that is why my tank is not getting that hot.

How hot is your tank getting? Do you suffer the pressure drop after a fill syndrome?

[MANN]

How hot is your tank getting? Do you suffer the pressure drop after a fill syndrome?

Defiantly not hot to touch (without the cover on. Here lately I dont use tank covers.). It is warm, but not hot. I have no idea about pressure drop I never look at my pressure gauge. I will next time.

[DevilMan]

Which is why I have mentioned it over and over. I've looked for videos online of the fill process but can't seem to find any.

I do know for a fact that it was down in SoCal for one of the AO shin digs that the place takes your bottle and pops it full FAST! I also know that a 3K bottle got popped full of 4500 PSI and nothing popped loose on it.

If some of you are out this weekend and can get some footage of different places there could be a legitimate comparison.

DM

[hunter100]

I also know that a 3K bottle got popped full of 4500 PSI and nothing popped loose on it.

DM

If I recall correctly, the burst disk on a 3000 psi cylinder goes at 5000 psi, which means everything (the reg, seals, cylinder, etc) should be designed to fail above 5000 psi. Still is scary though.

[DevilMan]

If I recall correctly, the burst disk on a 3000 psi cylinder goes at 5000 psi, which means everything (the reg, seals, cylinder, etc) should be designed to fail above 5000 psi. Still is scary though.

The HP burst disk yes... but what about the LP one? What about the 3K reg with 4500 on top of it?

DM