Burst Disk Questions...

[netmage]

What else besides doubling up standard disks are people using to eliminate the worry of blowing a disk while getting a fill? Unless I learn differently, i'll probably just stick to doubling up to new disks in each valve i set up, however if a more cost effective method is available that is just as "safe"... i'm game.

Back in the day, at a fairly prominent S. Florida fill station... The policy was if you wanted a 'cave fill',.... they requested you have the 5500psi disc... If you didn't, and it went on fill..., the lost gas was on you....

[Marchand]

[LiteHedded]

that is sexaaay

[IowaCaveDiver]

let us ponder this... those who are not apposed to SS no blow style discs.... what about the LP plugs? cheap, free... would this be safe? they seem to be approx. the same depth as a burst disc bolt, however they have an oring... if you were to use a viton 02 clean oring, would this be a solid/most inexpensive solution? Aside from normal dive shops seeing an allen wrench hole in your burst disc port, any cave shop probably wouldn't give it a second thought..... your thoughts?

[Marchand]

buy the appropriate size SS bolt at the local hardware store, cross drill the head so that it looks like your standard bust disk bolt, put the little plastic washer thing in and then
the new bolt.

A little more work than using a port plug, but no body will be able to tell and you'll be able to get fills anywhere.

[Sludge]

Can anyone come up with a downside to using a 3500 disk?

BTW, in 22 years I've NEVER seen a properly-cared-for disk go (other than when it was supposed to).

[LiteHedded]

Can anyone come up with a downside to using a 3500 disk?

BTW, in 22 years I've NEVER seen a properly-cared-for disk go (other than when it was supposed to).

I don't really know how these things work but would it blow or be likely to blow when you get a 38-3900psi fill?

[outofayr]

Not sure IIRC, but it seems that burst discs are designed to go at around 5/3 working pressure, +/- 10%. So a 3000 psi tank should have a disc for 5000 psi, and a 3442 or 3500 psi tank will be around 5250 psi. At least that what mine are.

I'm with Russell here. No need for double discs or no blows. I run the 5250 discs in all my doubles, and don't have issues with routine 3500-3600 fills.

Brian

[alias]

Do 2640 tanks only have 4500 discs (if original)?

[FW]

Can anyone come up with a downside to using a 3500 disk?

BTW, in 22 years I've NEVER seen a properly-cared-for disk go (other than when it was supposed to).

"Properly-cared-for" is the key here. If you are going to over pump, then the disks need to be replaced every year.

I have had them go, but they were the original disks, so I have no-one else to blame.

As for solid plugs, some shops won't fill if they don't see the holes. FWIW, it is really hard to drill SS bolts, and have them look like official factory plugs.