How bad is flash filling for HPA tanks?

[Koosh]

Just wondering... The local feild here just got push button HPA, he was bragging how any tank of any size could be filled in 2-3 seconds... I asked if that was bad for the Nitro tanks to be filled that fast, and this was his reply (on their forums)...

"Yeah...thats what I think to but......that system has been in use by the PSP and NPPL for 2 years with no incident and insurance companys have rated it as safe....that is a good question koosh...one I have wondered about for a while."

Any definitive info on this?

[SlipknotX556]

Yeah, we had one at my field, never hurt my tank. Its so much better, then waiting for someone else to fill your tank.

[Steelrat]

I have the local scuba shop fill my tank occasionally. When i mentioned how fast the fields fill the tanks, they looked horrified. Thank god the tank manufacturers do such a good job, or someone would have died by now.

[Beemer]

From Slartybartfast

Don't ask us. Ask a professional.

But, look at page 15 of this:http://hazmat.dot.gov/exemptions/E13105.pdf

Discoloration may be a sign of heat damage meaning the cylinder is now unserviceable/dangerous.

DON'T FLASH FILL!!
One filling procedure:http://www.survivair.com/techbulletins/TB103.pdf

This document and others all warn to fill at a maximum of 500 psi per minute. There are numerous warnings against fast/flash filling.

From this thread...../

http://www.automags.org/forums/showthread.php?t=144617

[Won Hunglo]

Flash filling can stretch & over heat a tank. It can fail the elasticity portion of the hydro test if damage has occurred. It is hard on the reg & fill nipple o-ring too. Always fill slowly if you can.

[Torbo]

if it were to over pressure, wouldnt the high pressure burst disk blow, thus saving you and the tank?

[jewie27]

Here's my input, since I've worked in a SCUBA shop for 2 years. ALWAYS fill slow if possible. The best fill rate for paintball HPA tanks is 100 PSI per second. The only problem is that the self-serve push button stations fill fast which are more risky than SCUBA tanks. The safer way is to use SCUBA TANKS or compressors that allow you to control the flow rate.

Here's why fast fills aren't good: by laws of science, air moving quickly through small spaces (regulators, fill ports) cause friction and friction causes HEAT to build up. Heat can cause bad things to happen to a tank. (possible explosion or tank stretching) The most common problem is that hot fills never give you a complete fill. Tanks that are filled fast heat up a lot, then when they cool down to room temp (72 farenheit) you lose pressure. So your 4500 psi tank filled quickly may only give you 4000 or maybe less depending on how fast you fill it.

Quick tips:

Fill at a rate of 100 psi per second when possible.

Remove tank cover when filling to reduce the amount of insulation around the tank, so it will stay cooler.

[TDonovan]

I really only have the pushbutton setups around here...

What should I do then? Last time it was filled, the fill nipple indeed started leaking right after and I still haven't gotten it fixed.

Should I just fill the tank with the push button like 500 psi at a time and let it sit or something?

[jewie27]

that might be a good solution, though it's a slower. I want to suggest to these companies that make these self-serve fillers that the stations be regulated to 100 psi/second. Will somone help me get the word out?

[Setzer]

100psi/second is over 10 times the recommended fill rate, and is considered fast. Yeah, no one likes waiting in line, but saftey is worth a couple minutes, isn't it?

[Chojin Man]

wouldn't that burden be up to the fields and not the manufactures? i mean don't the fill stations allow you to set the max fill rate?

[Setzer]

wouldn't that burden be up to the fields and not the manufactures? i mean don't the fill stations allow you to set the max fill rate?

Yes, it shold be up to the fields, but until the insurance companies mandate it, they won't change. And an insurance company won't do anything until some tank blows and kills someone. So while the fields could do somthing about it, they won't because their insurance companies consider flash filling safe.

[xXHavokXx]

500 psi per minute is 9 minutes for a full fill at 4500psi, or 6 minutes for 3000psi. Imagine being at a tournament of 25 teams of five guys. 125x 6 = 750 minutes for one fill total or over 2 hours with one fill station, 4 hours with three, 2 hours with 6 , then yu have to account for multiple games ending quickly and other factors including everyone will want a fill before their first games. Huge events like NPPL, PSP and IAO would come to a grinding halt as getting air would be the new comperative sport.

[Steelrat]

500 psi per minute is 9 minutes for a full fill at 4500psi, or 6 minutes for 3000psi. Imagine being at a tournament of 25 teams of five guys. 125x 6 = 750 minutes for one fill total or over 2 hours with one fill station, 4 hours with three, 2 hours with 6 , then yu have to account for multiple games ending quickly and other factors including everyone will want a fill before their first games. Huge events like NPPL, PSP and IAO would come to a grinding halt as getting air would be the new comperative sport.

This must be a common feeling, that increased speed in filling is worth the corresponding trade-off in safety. However, if there is ever a serious injury or fatality caused by improper filling, watch how quickly things will change. We'd probably better off finding out a workable solution before one is forced on us.

[Setzer]

500 psi per minute is 9 minutes for a full fill at 4500psi, or 6 minutes for 3000psi. Imagine being at a tournament of 25 teams of five guys. 125x 6 = 750 minutes for one fill total or over 2 hours with one fill station, 4 hours with three, 2 hours with 6 , then yu have to account for multiple games ending quickly and other factors including everyone will want a fill before their first games. Huge events like NPPL, PSP and IAO would come to a grinding halt as getting air would be the new comperative sport.

That just doesn't fly with me. Its okay to disreguard saftey because there are games to be played? Now if someone gets killed, will you still feel the same way? I hope it doesn't have to come to that, because then it will be too late.