ZDM series automatic recirculation valve

ZDM series automatic recirculation valve is a kind of pump protection device. It automatic protect centrifugal pump when pump body occur cavitation damage or unstable (especially conveying hot water at low load operation medium). Once pump flow is lower than the preseted flow, bypass can completely open to ensure the minimum required flow pump. Even running fully closed, namely running flow is zero, the minimum flow can also pass bypass for Automatic Recycle. Pressure reduced through the multistage bypass pressure reducing valve.
ZDM series is suitable for bypass with high pressure differential, maximum pressure differential is 30MPa, and specific choice is determined by factory. Multistage decompression type M type bypass can eliminate noise made by high-speed flow medium, prevent damage of cavitation erosion and braising to valve components.


  • Prevent cavitation multistage decompression bypass, reducing velocity, suitable for high pressure conditions
  • Forgde valve body, or you can choose carbon steel or stainless steel material, etc.
  • Standard bypass non-return function, maximum working pressure differential is 30MPa.
  • Pressure grade from PN16 to PN420, diameter from DN2to DN500.
  • Can select manual bypass operation function, used in fault.


  • Body type: Three-way forged valve
  • Nominal diameter: DN25, 32, 40, 50, 65, 80,100, 200, 250, 300, 350, 400, 450, 500
  • Nominal pressure: PN 16,25,40,64,100,160,250,420 CLASS 150, 300, 600, 900, 1500, 2500LB
  • End connection: Flange, FF, RF, RTJ, BW, SW etc.