Self-acting pressure reducing controllers

RCRB – flanged controllers
RCRBm – screwed controllers

Direct-acting pressure controllers are used in heating and industrial systems. Designed for maintaining pressure between 0.2-1.6; 1-2.8; 1-3.5 or 2.5-7 bar. Compatible with cold and hot water or steam* up to 180ºC (200° -special version, RCRB), up to 150ºC (RCRBm) and non-flammable gases up to 80ºC.


  • pressure reduction downstream of the valve,
  • installed on the supply side,
  • high accuracy – maintenance-free,
  • no external energy required.


All pressure reducing controllers are medium-controlled proportional controllers. The valve disk (3) pressure is relieved by the relief unit (4) to guarantee stable regulation. The device has two components:
– control element (valve), including: valve housing (1), seat (2), head (3), relief unit (4), spindle (5);
– control unit (cylinder), including: impulse lines (6), cylinder disks (7), springs (8), cylinder spindle (9), adjustment nut (10), cylinder housing (11).

Principle of operation

The medium flows from the valve chamber (A) in the flow direction indicated. Pressure control signal is transmitted to the controller chamber (B) via the impulse line (6). The chamber (C) is connected to the atmosphere. The gap between the socket (2) and the head (3) depends on the differential pressure maintained between the chambers (B) and (C). The increase in regulated pressure over the preset value will close the head (3) until the differential pressure between the chambers (B, C) reaches the preset value at the spring (8). The pressure is set with an adjustment nut (11). The valve head (3) is normally open (no power supply).

Installing controller

Controllers must be installed on horizontal lines. Flow direction must correspond to the direction of the arrow on the housing. To ensure correct operation, thecontroller must be protected with a filter or a strainer. Install a condensing vessel when using the controller as a steam pressure controller.


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