What is the difference between a pressure reducing valve and a pressure relief valve?
pressure reducing/regulating/ relief/release/ such several names are there in the market
Anoop:
Pressure reducing and pressure regulating valves are essentially the same though pressure regulating valves are considered to be more accurate in maintaining the set pressure. Also, the term pressure reducing valve is more commonly associated with liquids while pressure regulating valve or more correctly regulators are use only for gases.
Both these types of valves control the flow of the liquid or gas through pipes and tubes.
Pressure relieve valves are valves that will vent a device at a preset pressure. They are typically safety devices. The fluid is vented to an overflow area that may simply be the open environment. These types of valves are controlled by springs or are designed as rupture plates that fail at a predetermined pressure.
Pressure release valves are manual valves. They can be combined with pressure relief valves. They require manual intervention and will release excess pressurized fluid in a safe controlled manner.
I hope that these definitions help you. If you have other questions do not hesitate to ask.
Niel
There all the same. Just different names for the same thing.
They are all pressure relief valves that are design to open when there is an over pressure in the fluid line. This overpressure is usually 10-15% of the intended pressure in the line. As said be Neil, they are set by springs and sometimes can be set by pilots, and they open when they see the overpressure.
I dont think that there are different names for them when they are put onto different service lines (steam, water, gas, chemical, whatever) and there arent different names for ones that can be opened by hand. Section 8 of the ASME code states that a packed lever needs to be used on a pressure relief valve if the temperature of the working fluid is above 140F.
Check out: Farris, Kunkle, Crosby and Consolidated relief valves is you wish to gain more info about these
