I am working on some data sheets of ON/OFF valves. In those data sheets I am having confusion about the mentioned process data.
I have attached a drawing about the arrangement of valves in PID.
Drawing1.pdf 87.86KB 14 downloads
In the drawing there 2 possible arrangements according to the pipe class specification.
For Figure-1, the data sheet of ON/OFF valve contains the process data of inlet N2.
While for Figure-2, the data sheet of ON/OFF valve contains the process data of process line instead of inlet N2 (Both are different: process line-liquid, N2-gas).
But the purpose of ON/OFF for both cases are same (flow of N2 in the process line).
All these variations (observed from the PID's) are due to the change from Pipe Class Specification: SS14 to SS10 or vice versa.
Usually we provide inlet data for sizing a valve for which it would really be operated.
Is this how process data are selected according to the pipe class specification for valve sizing?
Or are there some other factors that have to be considered other than inlet data?
Would be very grateful for getting any help.