Regulators without auxiliary energy

Regulator without auxiliary energy or pressure reducing valve for steam, water and gases, is applied in lines and plants under pressure to reduce the pressure of fluid flow.

Pressure reducing valves can be used as individual, standalone components or as a part of pressure reducing stations. Pressure reducing valves production program of "KB Armatura" consists of two main groups:

• The first group includes pressure reducing valves with cast iron casing, which corresponds to nominal pressure PN 16 and and is designated RV-G.
• The second group of pressure reducing valves, designated RV-Č, refers to the valves which housing is made of cast steel and corresponds to nominal pressure PN 40.

Both groups have two constructions of the impulse part:

• Synthetic rubber membrane
• Compensator made of W.Nr.1.4571

The type of impulse body is designated with "G" = rubber, or "K" = compensator.

Maximum reduced pressure is 12bar for PN 16 and for PN 40.

For the reduced pressures up to 3 bar the valves with membrane of synthetic rubber are used. The compensator of W.Nr.1.4571 is used for pressure reducing valves for reduced pressures over 3 bar.

Construction

Pressure reducing valve basically consists of two elements:

• A regulation part
• An impulse part.

Regulation part makes housing of pressure reducing valve with cone.

The impulse part is a membrane or a compensator.

These two basic elements of pressure reducing valve, are structurally related with the connecting pipe, which may be of different length. Longer connecting pipe is used for steam and flow fluids whose temperature is higher than 120º C.

Basic elements of pressure reducing valve:

1. An impulse part (a membrane made of rubber and compensator made of W.Nr.1.4571)
2. A regulation part (housing, cone)
3. A connecting pipe
4. An adjusting screw.

Technical characteristics

Production program of pressure reducing valves with basic technical characteristics is systematically presented in table view.

While following data from the table, it is necessary to take into account the interpretation of marks of pressure reducing valves according to the explanation from the chapter "Application".

Important remarks when choosing valves

Achieving the pressure differences for various fluids

Water – There is no difficulty to reduce the high pressure to very low pressure in one cascade

Compressed air – Very significant pressure difference between input and output can be achieved.

Steam – Theoretically, high pressure steam and low pressure steam can be equaly reduced in one cascade.

In the realization of large pressure differences in pressure reducing valve, high speed is achieved, which gives a very poor working conditions and reduce the lifetime of pressure reducing valve.

Pratcically, input and output pressure ratio of P1/P2 = 4:1 should not be overcome. Depending on this ratio it is recommended to use a diffuser. The size of the diffuser depends on the exit pressure. The nominal pressure of diffuser is equal to the nominal pressure of the pressure reducing valve.

The pressure reducing valve selection is carried out according to the actual ordinal Kv values, where Kv min should be at 40% of operation and Kv max at 60% of operation. Entering the diagram with the obtained min and max values of Kv we choose nominal size of pressure reducing valve.

Applicability of pressure reducing valves for different pressures depends on the temperature of the fluid flow.

This relation for pressure reducing valves is shown in following tables.