Premature Failure of Rupture Disc

[ak1965]

We have Rupture Disc + PSV combination installed on many equipment in our petrochemical facility.


However, experience is not good, many RDs are failing prematurely without overpressurization or overheating above the specs. As a result, PSVs are beingg kept in closed condition to avoid fouling.

What could be the possible reaosn of premature failure in RDs? we have checked PMI of 01 RD that conformed its material as SS316 which is as per specs.

 

[Fzob]

A few things come to mind

1. Operating too close to the set pressure.
2. Pipe line pulsations
3. Corrosion. (even small amounts of corrosion can adversely affect a RD)
4. Improper burst tolerance range on disc.

http://www.iceweb.com.au/Technical/rupture_disk_specification.htm

When you say PSV's are being keep in closed psotion, what do you mean? If they are gaged shut somehow, you have created a very dangerous situation.

 

[abcmex]

dear ak1965,
this arrangement is commomly used in the industry. I am tempted to assume there is a design flaw. I recommend you to search for profesional help. The situation could easily get very dangerous. Eng-tips is a great place to search for information but probably not ideal in your case.

rgs

 

[hacksaw]

you are dealing with materials selection

if suitable materials cannot be identified, then you may need to consider purging/flushing to protect the disc or consider redesign of the process

 

[ash9144]

This will sound silly but I have seen it before. Make sure they installed in the correct orientation, confirm the direction with the manufacturer.

 

[sshep]

We have lots of these installations, many of which fail as yours have, and on investigation it usually found that they are doing their job- i.e. they buckle on overpressure. The two most frequent causes are blocked in thermal expansion, or small pressure transients (spikes) from valve opening or pulsations.

How do you vent between the RD and the PSV?
How do you detect a rupture disk failure?
What sort of pressure are these set at?

Rupture discs cause all sorts of problems- detection, frequent replacement, cost, drips from the excess flow check, etc. If the fluid is not as corrosive or fouling as the original design supposed, you should consider doing away with the RD and redesign the relief valve to have contact with the process.

best wishes,
sshep