Safety Procedures for filling with HPA Compressors

Hi everyone. I had a close call with my compressor yesterday (in another thread) and I am really starting to rethink how I am filling and how I can make it safer. I thought I would start a thread where I would ask people for their learned process for safely filling with a compressor. 

I have a Hatsan Lightning Compressor and three tanks, 2 are small 90 ci Ninja's and the other is a Scott SCBA tank that is still 2 years from end of life (without recertification). I bought a gold filter from ebay and it was the part that failed when the quick connect collar split right around 4300 PSI and it spit the whip with male to male out at my head. 

In another hobby of mine (drone racing and RC Cars) we use lipo batteries and they are basically grenades if not cared for... a lot of people lost houses to those lipo's. I built a battery bunker to store and charge my lipo's out of cinder blocks and a slab of granite. That way if one went up it would be contained. Is there anything like that in which people put their tanks while filling? I have seen the system that the fire departments use to fill and they put the tanks in a container to fill.

Other than that, is there some procedures people use to make it safer? For instance, I am still confused on the best shut down procedure for filling. I normally close the valve on the SCBA tank and then quickly shut down the compressor which has an auto purge on it to vent the pressure and water. Is that what others do?

I am hoping we get lots of input here as it will help other newbies like me to do this in a safe way.. HPA is nothing to play with.

Thanks. James

PS - This is the part that broke...

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I'm not sure where you can get them, but my Stikman fill station that I use on my 60-minute SCBA tank has a male 1/8 quick connect fitting with a check valve. This prevents air from escaping back out of the tank should something between your compressor and tank let go. If your whip flailed around more than a second or two, then it was because air was coming back out of your tank. I connect my air compressor line to that fitting when filling the tank. Even regular shop air compressors have a check valve where the air enters the tank. This, I think, is the single most important safety device you can employ when filling your tanks.
 
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I was using a Stikman fill station on the SCBA tank, and then a male to male connector off the gold air filter. Thats the part that failed and it shot that connector with the stikman whip at my head. I had just about finished closing the tank valve so not sure if it was that or the check valve, but it didn't whip around. I imagine that it would have taken a nice chunk out of my nose had it hit though.
 
I really am liking the idea of a switch to run it all but it would have to be a pretty hefty one as its using close to a full 20 amps to run that compressor. I wonder if my generator would power it, then I could put it all outside when I am filling, which isn't really that often. If I set the auto shutoff to 4300 psi I could just let it go... Or I could build a bunker out of cinder block like I did for my lipo charging and storage area.. put everything in there and let it run, and unplug it if something goes wrong.

Maybe overkill... 
 
I have the Yong Heng compressor but do not use the auto shut-off feature. I use a check valve in the hose coming from the gold filter to my micro bore hose to my tank. Since I have the check valve I open the bleed valves on the Yong Heng when I reach fill pressure and don't worry about loosing tank pressure. That still means if my micro bore hose fails I will loose air going to my tank. I think now it would be best to have the check valve with a female to female foster fitting at the tank itself. I also think as others mention tethering the fill lines is a good idea. Bill
 
Were you closing the main tank valve when it blew? I always open the bleed valves on my Yong Heng then immediately shut off the compressor. I only close the main valve after that. If you close the main tank valve while the compressor is still running, and don't immediately open the bleed valve on the compressor, the pressure between the compressor and your tank can rise very rapidly. The burst disc is supposed to prevent excessive pressure, but they don't always blow out as fast as they should. I only say this because the one time I had a burst disc blow, I discovered that I had only opened the main tank valve slightly. I believe that caused too much restriction to the flow of air into the tank. You are right to be concerned, as this is a potential danger with filling our own tanks. One more question: Is that a brass quick connect? I don't know what the ratings are on the brass fittings. I have only used steel fittings so far. This is definitely something we need to learn more about. Thanks for sharing your experience with us. This is how we learn.
 
1537740494_12310719745ba80ece5fec00.25192024_FX Fitting.jpg


This is the fitting that came with my FX Crown. Brass body, but steel collar. So, maybe I'm wrong to be leery of brass entirely. However, I wonder about the collar. Maybe that is where the highest stress is, and warrants a stronger metal? I have not actually used this fitting yet, as I already have a female quick connect on the hose of my Stikman. More food for thought.
 
The fitting above is the same as what Best Fittings is selling. I recommend using a non-return valve at the tank and the pump. It won't stop the leak or burst but it will limit the damage and loss of air. I've had a few hose bursts and a few Orings fail but never had anything explode. Using different branded or unbranded fittings together is probably the cause of most joint failures. They all seem to use slightly different dimensions. I do mix and match mine but I'm very careful about how they fit each other. A little bit of mechanical knowledge and a lot of common sense is required to operate these things safely.
 
I'm not sure where you can get them, but my Stikman fill station that I use on my 60-minute SCBA tank has a male 1/8 quick connect fitting with a check valve. This prevents air from escaping back out of the tank should something between your compressor and tank let go. If your whip flailed around more than a second or two, then it was because air was coming back out of your tank. I connect my air compressor line to that fitting when filling the tank. Even regular shop air compressors have a check valve where the air enters the tank. This, I think, is the single most important safety device you can employ when filling your tanks.

I have a Stickman. I thought the male fitting was just for storing the female Foster, but then watched the video and they talk about using the male fitting for cascade filling so it must have a check valve. They should add instructions on how to use it to fill the tank with the compressor--I've been using the female microbore hose. I really like the idea of having a check valve to prevent loss of air from the tank if something goes wrong (it also greatly reduces the potential energy released if a fitting goes).

Thanks for posting this!
 
I bought all stainless whips and connectors.. man, its amazing the difference in the quality feel of them compared to the brass crap they send with the filter etc. The one on the compressor is actually pretty nice. Even my new stainless steel male to male connector is much better fitting and feels totally solid. So my suggested procedure for safety is to replace all the crappy brass connectors with higher quality stainless ones, just as others have said. These are the ones I bought.. much better.

71l5jEviOtL._SL1500_.jpg
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I have also got the brass QD connectors that came with the gold filter. Visually they are quite well made and the fitting to the male connectors I use is very solid but I use only male connectors that measures exactly 8.00 mm in diameter. I have some other male connectors with looser tolerance measuring 7.79 mm and I never use them. 

I believe the problem of the OP's brass connector that had the retaining ring cracked open during use is not so much due to poor workmanship but material defects that cannot be detected visually. Are stainless steel connectors a lot safer ? I used to believe so but I started to doubt after I have taken a close examination to my stainless steel connectors recently. The material is actually rather soft as evidenced by dents on the male connector as well as the balls on the female connector. The balls in these stainless connectors are smaller than those in the brass type so the concentration of stress higher. I am not trusting the connectors I have got in hands anymore, brass or stainless. If anyone knows where I can get more quality connectors, I would like to hear it. 

dents on the mail connector

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dents on the balls

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the ball on the left is from stainless connector, that on the right side is from the brass type : 

1538231256_8514777585baf8bd82b1a55.02650773_stainless QD ball ( left ) brass ( right ) low resol.jpg

 
I bought all stainless whips and connectors.. man, its amazing the difference in the quality feel of them compared to the brass crap they send with the filter etc. The one on the compressor is actually pretty nice. Even my new stainless steel male to male connector is much better fitting and feels totally solid. So my suggested procedure for safety is to replace all the crappy brass connectors with higher quality stainless ones, just as others have said. These are the ones I bought.. much better.

71l5jEviOtL._SL1500_.jpg
61-ppWVpH5L._SL1500_.jpg
61YKehCptOL._SL1500_.jpg



Where did you get your fittings and hoses?