Burst Discs....to replace or to not replace?

[bobbyp10]

There seems to be alot of dispute about whether or not to replace burst discs on visual inspections, hydro inspections, valve overhaul etc etc.

My question: If a burst disc is reoved from a valve, does it automatically have to be replaced, ie brand new?

If not, is the torque specification extremely important? (Given for a new disc there is torque specs, do they apply to used burst discs, even if only a year or 2 old).

 

[WD8CDH]

Since a disk can't be put back in the exact same place after it has been removed, it should be replaced with a new one. A re-installed used disk could have a higher or lower burst point than a only once installed burst disk. A one piece burst plug supports the disk differently and usually can be reused if not corroded.

 

[zaberman1]

torque is important since it properly sets the b-disk

 

[DA Aquamaster]

Replacing with each VIP is excessive.

Field experience with replacing burst discs every 5 years at hydro test has been very positive and successful in regard to preventing unintended burst disc failure.

Torque is important, but oddly enough I have found that it is sometimes not sufficient to prevent a small leak past the disc, so I leak test and if a leak is found, I torque it slightly tighter.

What is also important is to apply the specified torque rapidly to prevent the plastic washer from deforming. Deformation of the plastic washer is also the major reason for fairly low torque values in the first place.

Once it is installed with no leaks, use an "if it ain't broke, don't fix it" approach. There is no reason to remove it annually for VIP or even for a valve rebuild or subsequent annual O2 cleaning. If you do remove it, replace it with a new assembly.

 

[Doc Harry]

torque is important since it properly sets the b-disk

Gotta reference for the specs?

 

[zaberman1]

the first one that comes to mind online:

2001 Cylinder Valves Manuals

 

[Doc Harry]

the first one that comes to mind online:

2001 Cylinder Valves Manuals

Mucho gracias!

 

[AbyssalPlains]

Mucho gracias!

Muchas

 

[akdeepdiver]

Gotta reference for the specs?

Depends on the valve you have. Each manufacturer has different specs.