Hi Every one I have a question regarding the bursting disc .. firstly i will say i am fairly less experienced process engineer i will apperciate your guiadence to better understand the bursting disc functionality as i do understand it is there to protect against vessel over pressure .

The reason i asked the above question is that because we have exprienced bursting disc failure on one of the vessels, but on investigation it was found out from the PLC trends that the maximum pressure peak in the vessel was 1.5 bar and then pressure declined , the brusting disc was set at 3.88 bar according to process requirement , looking at the the maintenance regime we change them after every 2 years , therefore the bursting disc in question was due to be replaced this year shut down which is due in 3 months time from now , this type of premature failure has never been reported before , looking at the change in process the only thing which i can see is this vessel goes through positve pressure to negative pressure (vacuum) .

I am not sure if cycling btw positive and negative pressure will make any diffrence to integrity of the bursting disc at all ?

PlantEngineer,
Welcome...

Some questions for you to see if we can identify the problem...

Are you saying that normally the system was designed for ONLY positive pressure and now operator has changed the operating mode which lead to positive and negative pressure in the tank ?

How often was the cyclic operation ?
Was the original RD directing acting or reverse acting type ?
Was the replaced RD directing acting or reverse acting type ?
Was the installation correct ?
Have you or your team ever checked if the RD failed to inflow or outflow ?