Pistons

Valve pistons and piston service kits with verified model and flow-configuration references. Match the valve label and exact part number before service.

Piston selection

Flow direction and valve family control piston fitment

Main pistons route water through service and regeneration cycles. Standard, filter, low-water, downflow, and upflow pistons are not cosmetic variants. Match the valve model, service configuration, and exact OEM number before selecting a replacement.

For Clack valves, compare WS1 with WS1.25. For Fleck equipment, begin with the relevant model page or the 5600 piston guide. Continuous drain alone does not prove that the piston is the failed component.