Q & A > Question Details
What is the working principle of pressure differential control valve.
26/11/2016 A: Sridhar Balakrishnan, Bharat Oman Refineries Limited , laksrid@yahoo.com
Two types are available , they are flow mounted and return mounted . DPCV utilizes a diaphragm that segregate the top and lower chambers of the valve and a spring-loaded piston. The piston is secured to the diaphragm, and obstructs the valve when differential pressure rises and opens it as the differential pressure falls. During periods of equilibrium between diaphragm pressure and the piston spring, the valve position remains steady.
07/11/2016 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
It depends on the the application. For instance, n an FCC you control the differential pressure between the reactor and the regenerator high enough to allow the catalyst slide valves to operate in a reasonable range and high enough to get a reasonably low risk of getting a flow reversal in an upset.
For something like a desalter you control the differential pressure across the mix valve to provide a constant level of mixing.