Pressure Control Valves

The answers so far may be good starts, but there are many other types and arrangements of pressure control valves. It's a big field.

The (Parker) Refrigerating Specialties A4A series of regulators alone has a dozen or more control schemes and combinations.

It is based purely on application...I assume this is not for farm irrigation water.

Simply put, then:

1. The body material is dependent on the line spec eg if the line is flanged ANSI 600#, so must the body also be rated and flanged.

2. The valve trim (innards) material is dependent on the line pressure and temperature, and whether the service is corrosive/ not eg in high pressure steam service, the steam will cut soft trim materials.

3. The choice of actuator depends on the line pressure it must operate against, and the port and plug sizing is also a function of such pressure eg a diphragm is used to overcome the internal resistance to the valve plug travel.

4. The valve size is generally smaller than the actual line size for cost effectiveness and the line size reduction also assists the pressure drop across the valve.

A little knowledge is dangerous.... All credible manufacturers will offer a design solution specific to your application, even if you don't know what a process data sheet is. My advice ? Pick up the 'phone, or google 'control valve manufacurers'

<...Pick up the 'phone, or google 'control valve manufacurers'...>

...which is why having a tame local valves distributor on speed-dial is such an asset.

Amen to that !