Self-acting back pressure regulators are simple control valves offering accurate control while being easy to install and maintain. They control the pressure upstream of the valve without requiring pneumatic or electrical control elements.
The UV 4.4 backpressure regulator is a piston-controlled, spring-loaded proportional regulator with relief for large throughputs. The valve housing is made of spheroidal graphite iron with a continuous epoxy coating while the valve cone is soft-sealed.
The inlet pressure to be controlled is balanced across the valve seat by the force of the valve spring (set pressure). If the inlet pressure rises above the set pressure, the valve opens. With decreasing inlet pressure the valve control orifice reduces, when the pipeline is depressurised, the valve is closed. Rotating the adjusting screw clockwise increases the inlet pressure.
These valves are no shut-off elements ensuring a tight closing of the valve. In accordance with DIN EN 60534-4 and/or ANSI FCI 70-2 they may feature a leakage rate in closed position in compliance with the leakage classes V (soft seal cone = 1.8 x 10-5 x ?p x D* [l/h], *D=seat diameter).