Pressure relief controllers is a direct-acting regulating pipeline fitting designed for automatic maintenance of water pressure in the direction of its flow.
The regulator automatically maintains the water pressure by changing the valve orifice. When the pressure increases relative to the set value, the regulator automatically opens until the water pressure equalizes with the set value.
The operating principle of the direct-acting regulator is based on the use of water pressure to move the valve closure. The degree of opening of the regulator is proportional to the deviation of the controlled pressure from the set value, hence they are also called proportional regulators.
Pressure relief controllers are installed in heating systems, heat exchange stations, boiler plants, and pumping stations, where they perform the function of bypass or support.
Pressure relief controllers can be replaced with indirect-acting regulators, which must include a pressure sensor, controller, and regulating valve with an electric actuator. Despite the higher precision of pressure maintenance, indirect-acting regulators are used only in cases where direct-acting regulators cannot be used, for example, when a DN200 valve or a very wide range of maintained pressures is required.