Pressure switch

[EEENGRX]

For a pressure switch that is connected to a rupture disk which also has a PSV. Is it advisable to have the same set point with that of the PSV or a little lower?

 

[waross]

It depends what you want to check with the pressure disk.
If you want a warning of rising pressures, then set the switch at the value at which you want an alarm.
If you want to detect a disc rupture of PSV operation, set the switch at a value that will be held open at normal operating pressures and close when the pressure drops due to the rupture of the disc or operation of the PSV.

 

[LittleInch]

What do you mean by "that is connected to"?

Generally you want your pressure protection devices to activate before your last line of defence (the RD) is activated. Most RD come with thin wire which are broken when the disc bursts which trips the system.

But replacing RDs is costly and time consuming.

They also have a certain degree of margin on their "set point" and are notorious for not liking short spikes of pressure.

Do you have a RD and a separate PSV? Sometimes you get this to cope with a high volume event whereas the PSV handles smaller amounts.

Like waross says - it all depends on your individual situation.