The Zurn Wilkins ZW209 Pressure Reducing Valve provides steady downstream pressure and allows high flow rates. Standard features ease maintenance and repair, and provide the lowest total cost of ownership.

Product Resources

Spec Sheets & Install

BIM / 3D Models / 2D Drawings

Related Documents

Back to Top

Features And Benefits

  • Holds downstream pressure to a constant value
  • Pressure gauges, wye strainer, isolation valves, and epoxy coating come standard
  • Globe, reduced port globe, and angle bodies available
  • 150 class flanged, 300 class flanged, grooved, and threaded end connections available for installation versatility
  • Perfect when high flow rates are needed
Lead Free
Retrofit or Replacement
Zurn Wilkins
Back to Top
Back to Top


Can the ZW209 be converted to a ZW209E in the field?

  • ​Yes.  The ZW209 can be converted to a ZW209E in the field.  Contact your Zurn Wilkins Representative, and they will guide you in the process to get the necessary components for your field conversion.

How do I size a Pilot Operated Pressure Reducing Automatic Control Valve?

  • ​In order to properly size a Pressure Reducing Automatic Control Valve, one must know the actual and desired hydraulic characteristics of the system where the valve will be installed.  The actual inlet pressure, desired outlet pressure, and the maximum and minimum flow rates must be determined.  Utilizing the Specification Submittal Sheet (found at, choose the size of valve that will satisfy the maximum and minimum continuous flow rates of the system.  Ensure that the valve will not be in a potential cavitation zone.  Utilizing the Zurn Wilkins Cavitation Chart (also found at, make certain that the desired pressure drop across the valve does not fall into the cavitation zone.  If the pressure drop across a single valve does result in cavitation, the use of two Pressure Reducing Control Valves piped in series would be warranted.  With pressure reduction performed by two valves in series, each valve is set such that the pressure is dropped in fairly equal steps.  This method ensures that cavitation will not occur, and serves to drastically increase valve longevity.  For more information on Automatic Control Valves, please visit our web site at

How does the ZW209 Pressure Reducing Valve react when air is entrained in the valve?

  • ​Air entrained in the valve will result in chattering, pulsations, and pressure swings.  The air must be bled out for the valve to function correctly.  Loosen the plug in the center of the bonnet until all air is removed.  This will stabilize the valve.  For more product information, please visit our web site at  Applicable products: All Automatic Control Valves

My rate of flow is below the minimum continuous flow rate of the Automatic Control Valve. How do I handle this situation?

  • ​Water flows under the minimum continuous flow rate for the Pressure Reducing Automatic Control Valve are generally handled by a Direct Acting Pressure Reducing Valve (PRV) piped in parallel to the Pressure Reducing Automatic Control Valve (ACV).  The PRV is sized according to its ability to flow the proper rate with a fall-off of approximately 5 psi.  When installed in parallel with the ACV, the PRV is set to the desired static operating pressure required by the system.  The ACV is then set 5 psi below the setting of the PRV.  This ensures that all low flows, from zero up to the minimum continiuous flow rate of the ACV, will flow through the PRV.  When the flowing pressure through the PRV drops to the set point of the ACV, the ACV will begin to open and provide flow up to its maximum continuous rated flow.  This method provides a seamless flow rate from zero up to the maximum.  For more information on Automatic Control Valves, please visit our web site at

What is the difference between the ZW209 and ZW109?

  • ​The ZW200 series valves are manufactured by Zurn Wilkins at our manufacturing facility in Paso Robles, Ca.  The ZW100 series product were private labeled for Zurn Wilkins by another manufacturer.

Will the ZW209 chatter and vibrate when flowing under its minimum continuous flow rate?

  • ​Yes.  All ZW209 Pressure Reducing Automatic Control Valves have minimum continuous flow rates.  Should the flow rate fall below the minimum continuous flow rate of the valve, chatter and vibration may be the result.  If the valve is intended to flow below the minimum continuous flow rate, a low-flow by-pass would be needed.  The Specification Submittal Sheet will indicate the minimum continuous flow rate for the ZW209.  Please contact the factory for additional help in properly sizing a low-flow by-pass.
Back to Top