Clack WS3 3" Filter Back Wash Valve V3BTZ-05

The Clack WS3 3" Filter Back Wash Valve (V3BTZ-05) is a large-format commercial backwash valve supplied by WrekinWater for high-flow filtration systems where 2" valves simply cannot handle the throughput. Sitting at the top of Clack's valve range, the WS3 platform is built for major commercial, industrial and municipal-scale filtration vessels, delivering the flow capacity and backwash performance needed to keep large multimedia, carbon or iron-removal filters working efficiently.

Technical specifications

Symptoms that mean you need this part

• A large commercial filtration vessel is no longer completing a proper backwash, leaving media compacted and filtration performance falling
• Site water pressure drops significantly during peak usage, suggesting the existing 3" valve can no longer pass the required flow
• Visible leaking, cracking or corrosion around the valve body after sustained heavy-duty commercial service
• The filtration system is due for a full valve overhaul as part of a planned commercial maintenance or capital replacement schedule

Why it fails / why it matters

At 3" port size, the WS3 valve range is built to handle serious commercial flow rates, and that scale of continuous duty puts real long-term stress on the internal seals, pistons and backwash mechanism. Years of high-volume operation, mineral fouling and water hammer gradually wear the valve's internal components to the point where backwash cycles become incomplete or unreliable, and because a valve of this size is a precision-engineered commercial assembly rather than a simple part, a worn WS3 backwash valve is generally replaced as a complete unit rather than repaired piecemeal.

Why buy this from WrekinWater

WrekinWater has served more than 50,000 customers over 15 years from its base in Bettisfield, Shropshire, and holds genuine Clack, Pentair Fleck, Autotrol and Kinetico stock covering everything from small domestic parts through to large commercial valve assemblies like this one. As a UK-registered company (Company No. 11000488) rated Excellent on Trustpilot, WrekinWater is a reliable source for installers and engineers specifying commercial-grade Clack WS3 equipment.

How to fit it

1. This is a large commercial valve and must only be installed and commissioned by a qualified water treatment engineer — this is not a DIY replacement
2. The engineer fully isolates the filtration plant, depressurises the system and shuts down the incoming supply
3. The vessel is drained and the existing 3" backwash valve is disconnected from the filter tank and the site's flanged or threaded pipework
4. The new Clack WS3 V3BTZ-05 backwash valve is fitted to the vessel and reconnected to the pipework, ensuring correct alignment of the large-bore connections
5. The engineer sets the backwash duration and sequencing to suit the specific media bed, vessel diameter and site flow demand
6. The system is brought back up to pressure and run through a full backwash cycle while the engineer checks for leaks and confirms flow performance