Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free, Flanged Connection.
Engineering Specification:
The Pressure Reducing Valve shall be a diaphragm actuated, pilot controlled valve. The main valve body shall be ductile iron ASTM A 536. The stem of the basic valve shall be guided top and bottom. The diaphragm shall not be used as a seating surface. All internal and external ferrous surfaces shall be coated with a high quality, fusion epoxy coating. The pilot control shall be field adjustable from 15 psi to 150 psi. The valve shall be certified to NSF/ANSI Standard 372. The Pressure Reducing Valve with by-pass shall be a ZURN WILKINS Model ZW209BP.
Features & Benefits:
- Holds downstream pressure to a constant value
- Perfect when high flow rates are needed
- Applicable to commercial, industrial, and irrigation
Application:
The Zurn Wilkins Model ZW209BP Pilot Operated Pressure Reducing Valve with Low Flow By-pass is designed for many applications where the reduction of high inlet pressures to safe and stable outlet pressure is required. The pilot assembly reacts to changes in downstream pressure allowing the main valve to modulate between the open and closed position ensuring a constant downstream set pressure. Once the downstream pressure reaches the pilot setting, the main valve will seal shut. When the main valve closes, the low flow bypass is set to a slightly higher pressure which allows it to handle very low flows up to 10 GPM when there is off peak demand. (An additional bypass may be needed to handle flows between the bypass and main valve minimum flow.) In addition the Model ZW209BP comes standard with blue epoxy coating internally and externally for corrosion protection as well as isolation valves and pressure gauges for quick and easy maintenance or repair.
Standard Compliance:
- Certified to NSF/ANSI 372* by IAPMO R&T
- ANSI/AWWA C530
- NSF® Listed-Standard 61 & 372* *(0.25% MAX. WEIGHTED AVERAGE LEAD CONTENT)
Materials:
- Main Valve Body: Ductile Iron ASTM A536
- Main Valve Bonnet: Ductile Iron ASTM A536
- Disc Guide: Stainless Steel
- Seat: Stainless Steel
- Disc: Buna-N
- Rubber Diaphragm: Nylon Reinforced Buna-N
- Stem: Stainless Steel
- Spring: Stainless Steel
*The closing speed control (optional) on this valve should always be open at least three (3) turns off its seat.
Operation:
The Model ZW209BP utilizes a pressure reducing pilot valve that installs on the discharge side of the control circuitry. The pilot is a direct acting, normally open, spring loaded, diaphragm actuated valve. The operation of the ZW209BP begins with accurately sizing the valve, then fine tuning the control circuit by adjusting the pilot spring to the desired downstream pressure. It is hydraulically operated and controlled by a PRXL pilot control, which senses pressure at the main valve outlet. An increase in outlet pressure closes the control. This causes the main valve cover pressure to vary, modulating the main valve and thereby maintaining constant outlet pressure. The Model PRXL low flow pressure reducing by-pass is preset to a higher pressure than the pilot control. The PRXL responds to pressure changes from the main valve outlet. When the pilot control closes, the Model PRXL by-pass valve remains open allowing water to flow through. The by-pass closes when the flow decreases and the downstream pressure reaches its set point.
The ZW209BP is not a substitute for a low flow by-pass in all cases. The valve is commonly used in buildings where 1-15 GPM low flows are common in off peak usage. Many factors should be considered in sizing a pressure reducing valve: inlet pressure, outlet pressure, and flow rates. The sizing of additional low flow by-pass valves are based on a minimum of a 50 psi differential between the inlet and set outlet pressure. To develop a smooth seamless flow response, it may be necessary to add an additional low flow by-pass valve to the ZW209BP installation to compensate for a range of anticipated flows below the minimum continuous flow rate. To control the opening point of the additional by-pass valves, set the valve you want to open first 5 psi higher in static downstream set pressure.
Notice:
Contact the Zurn Wilkins factory for additional by-pass recommendations based on your unique flow applications.
Technical Documentation:
- Zurn Wilkins 4-ZW209BP: Specification Submittal (PDF)
- Zurn Wilkins 4-ZW209BP: Installation & Operation (PDF)
- Zurn Wilkins 4-ZW209BP: Low-Flow By-Pass Instructions (PDF)
Media:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free Overview Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free Features & Benefits Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free; Commissioning a ZW209 Pressure Reducing ACV, Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free Animation Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free Troubleshooting Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free, All Stainless Steel Pilotry "SP" Option, Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free, All Stainless Steel Braided Hose "SH" Option, Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free PRXL Pilot Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free Reduced Port Bodies, Video:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free, Angle Bodies, Video:
Cross Reference:
Zurn Wilkins 4-ZW209BP 4" Pressure Reducing Valve with Low Flow By-Pass, Pilot Controlled, Lead-Free, Crosses:
- Ames 910GD-48
- Cla-Val 90-48
- OCV 127-3/1340
- Watts 115-74
Repair Parts:
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