Self-acting pressure reducers are simple control valves offering accurate control while being easy to install and maintain. They control the pressure downstream of the valve without requiring pneumatic or electrical control elements.
The pressure reducing valve RP 840 is a pilot-operated control valve consisting of a main valve for high flow rates combined with a millibar valve serving as pilot valve. Both valves are manufactured from deep-drawn stainless steel featuring excellent corrosion resistance and are arranged as a pre-mounted unit in a rack. The valve cone is soft-sealed.
In a pressureless pipeline the main valve is closed by the pre-tensioned spring.
If the outlet pressure falls below the pre-set nominal value, the pilot valve is kept open by its spring. The control medium flows off towards the valve outlet. Throttle D1 brings about a pressure drop, so that the control pressure in the main valve control mechanism nearly corresponds to the outlet pressure. The inlet pressure overcomes the outlet pressure and the closing spring force and opens the main valve.
Once the outlet pressure has reached the pre-set nominal value, the pilot valve starts to throttle. In doing so, the control pressure rises and pushes the main valve control mechanism to a regulating position. The throttles D1 and D2 serve to optimise the regulating behaviour. The bypass brings about rapid closure.
If the outlet pressure exceeds the nominal value, the pilot valve closes. The control pressure is equivalent to the inlet pressure. The main valve closes because the control mechanism diameter is larger than the valve seat. In addition, the spring also has a closing effect.
The valve is piped internally. The pulse lines must be installed on-site.
Please click HERE to view the RP840 One Sheeter