How do you select pressure differential valve?
For example it's Danfoss NRD, Sporlan ORD...
Danfoss don't say the calculation of determine quantity of NRD.
Sporlan gives:
In those cases where the ORI-10 is applied on systems with more capacity than the ORD-4
or when more than one head pressure control valve is
used, it is necessary to use two or more ORD-4 valves in parallel.
Could anybody explane how do you determine quantity of pressure differential valve in system with pressure regulating?