Fill Station Incident

Goferrin

New Member
While this incident didn’t happen while using a CCR, a lot of users do fill their own cylinders and/or use boosters. Mod’s please move if required

Late yesterday I finally finished plumbing in my new Booster. I had finished one twinset and was starting to partial pressure fill a second. Thinking the tank was empty, I casually but quickly fully opened the tank valve on the twin set. There was in fact 1800 psi of air inside the tanks and the result was a shock wave that sent the 4000 psi pressure gauge out of range. When this hit the closed Booster exhaust check valve, it blew the 3000 psi rated fill whip hose completely out of the crimp-on fitting.

My wrist was struck by the flailing hose while I was shutting off the twinset’s manifold valve, leaving me with the bruise shown. The bang left me with ringing ears for several hours and was loud enough to bring people running out of the house to see what happened.



Fortunately the twinset contained air and not oxygen and there was no HP oxygen related fire. Obviously if there had been HP oxygen the result could have been far worse.

A couple of learnings:
• Open all valves slowly, regardless of what contents or pressure you think is in the tank
• Be wary of leaning over hoses when filling as the jet of gas or flailing hose can do considerable harm or damage.

I’m looking into over pressure relief valves and if they will be fast acting enough to prevent a reoccurrence. However, as usual preventing an incident in the first place is the best solution.

Safe Diving
 
Thanks for sharing and thank God that you're ok. Nasty things can happen with these machines (I have a friend who lost one eye in a similar incident). Lessons to learn but all good when it ends allright.
All the best.
alin
 
Anything under high pressure has to be respected and treated with the utmost care and respect....Oxygen being even more so.

Be very careful with Over Pressure Valves as they also have the potential to cause you more grief than they can save especially if you are pumping Oxygen and then you have HP Oxygen venting off which can lead to problems and also the over pressure valve will reach very high temperatures quite quickly from the HP gas escaping.....That can also lead to a flash fire.

I have now had 2 whips blow the crimp off the hose and they were both the same style hose. They have a 2 piece fitting which consists of a separate barb and ferrule or tubular ring which is slid over the hose where the barb is fitted and then crimped. I now only use hoses with a 1 piece fitting where the barb and ferrule are connected to the fitting making it a lot stronger and resistant to failure.

I have attached a pic of one of the failed hoses showing the barb I described. I can post pics of both styles of fittings if it's of any use to anyone but be careful of 2 piece fittings they do fail!!!

Booster Whip 001RS.jpg

Regards,

Lance
 
That picture doesnt at all look like a high pressure hosetail lancer!

Two piece are just as good as one piece tails, Its the locking collar behind the thread that the ferrule locks into that distinguishes a high pressure one from a LP one.

As has already been stated, HP anything needs a high amount of respect, Always make sure the hoses are in the best condition possible.

While I have never seen one in use in the scuba industry, in the hose industry I am in, We sell whip checks to a lot of different customers so that in the case of a hose blowout, the hose can only move a few inches, This would be simple enough to rig up yourself and attach to the hose and to the cylinder valve.
whipcheckwrong_001.jpg
 
That picture doesnt at all look like a high pressure hosetail lancer!

Two piece are just as good as one piece tails, Its the locking collar behind the thread that the ferrule locks into that distinguishes a high pressure one from a LP one.

Hi Spiro, I can assure you it is a HP hose and was sold as part of a booster whip set manufactured and sold for CCR use. Both the original and the replacement hoses failed at less than the SWP whilst steadily boosting.

I wouldn't have bothered posting this if they were not HP booster hoses!!!

Regards,

Lance
 
Be very careful with Over Pressure Valves as they also have the potential to cause you more grief than they can save especially if you are pumping Oxygen and then you have HP Oxygen venting off which can lead to problems and also the over pressure valve will reach very high temperatures quite quickly from the HP gas escaping.....That can also lead to a flash fire.


As far as I am aware HP gas escaping from an OPV can't cause high temperature, since the gas is now expanding it will have a cooling effect and likely freeze open (Charles Law). OVP valves are essential in any gas compressor/boosting system, if there was a risk a O2 fire when using OPV's then you would not have any burst disks on O2 cylinder valves which are mandatory in North America to the best of my knowledge.


Rob
 
Thanks.

Just to clarify, what i am looking for is to vent pressure spikes rather than long term running at pressures past design.
 
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