Dear Sir,
During PSV calculations, I stuck at one scenario. Please help me.

Steam Turbine is used for driving a pump. HP Steam is used in the turbine. There is a Safety valve located on the outlet line of Turbine having MP Steam. Normal steam consumption of steam turbine is 25000 kg/hr. What should be the Safety valve capacity? Steam turbine curves should be used? or as a good engineering practice, the safety valve capacity should be twice the normal steam required? Is there any thumb rule ?

Please advice.

With Regards,
Pradeep Amale

The capacity of the PSV at the steam outlet of the turbine should be defined by the vendor of the steam turbine based on the steam conditions which you define. Having said that I've seen the general rule of thumb of 105% of the rated steam flow of the turbine as a guide for sizing the PSV.