What's the difference in construction of a check valve vs. a priority valve. From what I've understood it's rather a matter of application than construction which decides if it's a checkvalve or a priority valve.
Now for a
simple priority valve.......
Same valve as the NRV but this time a spring is on the rod thats attached to the plate keeping this this plate pushed against the flange. Your medium is flowing from right to left. You have an important system to the right of the plate and all pressures are normal so the plate is designed to be pushed open by system pressure and feed a not so important system to the left of the plate. So if pressure is lost to the right of the plate the spring will over come system pressure and close the plate (valve) to ensure the important system has the priority. ah ha
That all make sense chaps. Sorry if it sounds too simplistic but I dont know how technical you are
