Burst disc failure leads to over $2000 in property damage

[tbone1004]

I realize that's the purpose (combined with making the valve easier to handle), but I wonder about the side effect on thrust.

it ultimately directs it all straight outwards, but the flow isn't stable and the "nozzle" is quite large, so it shouldn't be able to get enough thrust out to gain sufficient acceleration to pick the tank up

 

[Rusty Shackleford]

I lost the back glass in my Jeep Cherokee to an overfilled LP 95 where the shop tech was talking on the phone. I asked him if I should bleed some gas off as he had filled it to nearly 4500lbs!

He told me to dive it like that.

It blew about 15 minutes after I got home. The overpressure blow out the back glass and this was with the driver side window being halfway down.

Thank God it didn't blow when I was driving, the overpressure would have likely popped my eardrums.

I got free Nitrox for a long time out of that. And it was a stock K Valve.

 

[TrimixToo]

This was actually covered in my inspector's class, and under my cert I'm not allowed to VIP a valve with a single axial outlet for the burst disc. Having seen one of those go many years ago in a dive shop, I can tell you from personal experience what happens if one of those fails with the tank standing up and unsecured. First, the side thrust pushes the tank over. Next, it hit the floor and starts to roll. Once the burst disc port is pointing more or less horizontally, the tank stops rolling. It begins to spin. It spins *fast*. I climbed up on a glass display case with everyone else running or climbing something nearby. Oh, and it's freakin' LOUD, too. Nobody was hurt, though.

Don't use these things. Newer style burst assemblies of both kinds have radial, opposed ports and develop nearly no net thrust. Valves are cheap, ankles and feet and shins not so much.

Just my .02.

 

[abnfrog]

that's a bummer that it damaged your truck BUT that is an illegal (cga ) disk it should have been changed .that being said it still may have damaged the truck ..yes it IS covered in the vip course with both psi and sdi ....that valve is 70s vintage (74) I believe so that's probably the original ....comfort over safety

 

[Johnoly]

.....Disassembly of the valve showed that the burst disc had sheared completely...

Anyone who's filled tanks has had a burst disk let loose on them and it's always scary loud. Glad no one got hurt. New pro valves are dirt cheap now days I threw away last year's to-be rebuilds because of the parts and time were cheaper than I could do a clean & rebuild. I haven't tried them yet but the MaxDive2007 new valves @$26 with free shipping is crazy low.

 

[Saniflush]

Thank you for the report. This is a really good thread to help get my learning on.

 

[tbone1004]

Anyone who's filled tanks has had a burst disk let loose on them and it's always scary loud. Glad no one got hurt. New pro valves are dirt cheap now days I threw away last year's to-be rebuilds because of the parts and time were cheaper than I could do a clean & rebuild. I haven't tried them yet but the MaxDive2007 new valves @$26 with free shipping is crazy low.

DGX also has their valves for $40 which are quite nice

 

[iamrushman]

sorry for your damages and thank you for putting the information on scuba-board...