High Pressure, Proportional Pressure Reducing Valve Model 820-PP ■ Long downhill lines □ Serial pressure reduction □ Leakage and burst protection ■ High differential pressure systems □ Protection against cavitation damage □ Throttling noise reduction The Model 820-PP High Pressure, Proportional Pressure Reducing Valve is a hydraulically operated, piston actuated control valve that reduces higher upstream pressure to lower downstream pressure at a fixed ratio. Features and Benefits ■ Robust structure, piston actuated - High pressure service ■ Line pressure driven - Independent operation ■ Elegant simplicity □ Most cost effective □ Simple to maintain □ Minimal external accessories ■ Built-in check feature - Replacing line sized check valve ■ In-line serviceable - Easy maintenance ■ Double chamber - Moderated valve reaction ■ Flexible design - Easy addition of features ■ Semi-straight flow - Non-turbulent flow ■ Stainless Steel raised seat - Cavitation damage resistant ■ Obstacle free, full bore - Uncompromising reliability ■ V-Port Throttling Plug - Low flow stability Major Additional Features ■ Solenoid control - 820-PP-55 ■ Closing & opening speed control - 820-PP-03 ■ Emergency pressure reducing valve - 820-PP-59 ■ Pressure sustaining - 823-PB

800 Series Operation The Model 820-PP is a pilotless, double chambered control valve. The downstream pressure is applied as the closing force on the top side of both the piston and the seal disk areas. The upstream pressure is applied as the opening force on the bottom side of the seal disk area. The net force, resulting from the two opposing dynamic forces acting on the actuator’s piston and seal, determines the degree to which the valve is open. The valve seeks the point where these forces are equal. As the ratio of the areas of the seal disk and the piston is constant, the ratio of the upstream...

BERMAD Waterworks 800 Series Typical Applications There are two major applications for the Model 820-PP High Pressure, Proportional Pressure Reducing Valve: n Long downhill lines: o Systems A1 and A2 prevent the downhill line from exceeding its pressure rating. n High differential pressure systems: o System B reduces cavitation damage and noise level by distributing the load of the high differential pressure. o System C illustrates protection of a circulation valve from high differential pressure and resultant severe cavitation. o System D shows protection of a level control valve from high differential...

Technical Data Differential Pressure Calculation Size Range: DN40-500 ; 1V2-20” End Connections (Pressure Ratings): Flanged: ISO PN16, PN25, PN40 ; ANSI Class 150, 300, 400 Threaded: BSP or NPT Others: Available on request Valve Patterns: “Y” (globe) & angle Working Temperature: Water up to 80°C ; 180°F Standard Materials: Body: Cast Carbon Steel; Ductile Iron; Stainless Steel 316 Cover: Stainless Steel 316; Bronze Internals: Stainless Steel & Bronze Seals: Synthetic Rubber Coating: Fusion Bonded Epoxy, RAL 5005 (Blue) approved for drinking water or Electrostatic Polyester Powder Differential...