Is a rupture (or burst) disk considered a pressure relief valve in Section I

[Stephen Max]

I can't find anywhere in Section I where it actually states that, and I don't want to assume anything. I am designing a forced-flow steam generator with no fixed steam and waterline for laboratory research use.

Thx.

 

[Stephen Max]

Hmmm. In Section VIII either a pressure relief valve or a rupture disk can be used for overpressure control, mentioning both specifically. Section I speaks only of pressure relief valves in part PG and says nothing about rupture disks except in part PVG, which is not applicable to me.

 

[racookpe1978]

A blow off panel or rupture disk is rarely accepted by customers because there is no isolation of the tank/vessel after the incident. The blow rupture disk must be replaced before ANY operation, including shutdown or drawing a vacuum (if in an equipment above a condenser), or draining and cooling the tank or reactor. So, instead of recovering (or preventing additional loss of the chemicals and reactants or further danger such as toxic gas or explosion gasses, or expensive gasses like nitrogen, CO2, or Argon, or potentially flammable gasses), a rupture disk forces the operation to be completely shutdown until the vessel is safe for entry, cooled down, allowed access and confined space entry, entry watches and recovery teams are in place, and work permits and LOTO processed.

A bit simpler if the rupture panel is accessible from the outside, but still a forced shutdown.

 

[Stephen Max]

Thank you for your reply.

If the customer actually desires a rupture disk rather than a pressure relief valve, does Section I allow it? I'm not seeing any indication that it does in part PG.

 

[metengr]

PG-67 does not mention or is silent on the use of a rupture disk. This means that the Code does not address it which means it does not prohibit use. However, the Code does address requirements for over pressure protection by stating a pressure relieving valve with blow down. So, I would strongly suggest you follow what is mentioned by using a steam-certified, pressure relieving valve with sufficient blow down capacity to ensure safe operation.

If you are designing a forced flow SG you should be very familiar with BPV Code Section I and involvement by the AI.