8 replies to this topic

[phoenixmoca]

When a rupture disk is installed at the inlet of PSV what is the relationship between rupturing pressure and set pressure? Should the minimum bursting pressure be more than set pressure? Is there any code or practice having the similar rules?

[latexman]

For me, most times RD burst pressure = PSV set pressure = MAWP.

[phoenixmoca]

So it doesn't care the rupture disc manufacturing range which may result in the rupture pressure greater than the protected vessel design pressure.

[latexman]

Specify +/-0, +0/-5, or +0/-10 %, whatever you can afford. Also, discuss this with RD mnfr.

[phoenixmoca]

Yes,latexman. With the different manufacturing range the minimum bursting pressure can be calculated. But I think the set pressure of PSV has no relationship with the minimum bursting peessure but is related to the design pressure of the vessel. And the set pressure and marked bursting pressure are all settled based on the design pressure of cessel.

[fallah]

When a rupture disk is installed at the inlet of PSV what is the relationship between rupturing pressure and set pressure? Should the minimum bursting pressure be more than set pressure? Is there any code or practice having the similar rules?

Hi,

 

As per various guidelines in API and ASME for a R.D./R.V. combination, the marked burst pressure of the R.D cannot be higher than the marked set pressure of the R.V., but can be lower.

For example in ASME UG-132 (a)(4)(a), for R.D./R.V. combination capacity testing, it is mentioned that: "...The marked burst pressure shall be between 90% and 100% of the marked set pressure of the valve."

 

Hope this help out...

[breizh]

Hi,

Consider the document attached (fike) 

Breizh 

[phoenixmoca]

So as ASME says the set pressure is only related with marked burst pressure rather than minimum burst pressure.

[Process_engg94]

Like in our refrigerant industry,RD is placed before PSV.
We keep,
PSV set pressure = Design vessel pressure - 1
RD set pressure = Design vessel pressure - 0.5