Wanner Hydra-Cell Pro^® Pump

Dampening Washers: Their Purpose and When They Are Required

Dampening washers go in most synchronous Wanner Hydra-Cell Pro^® frames: the 20, 03, 04, 10, 25, 35 and 66 models. This page is what they do and which builds actually need them.

Valve Plate

The valve plate holds the check valves. Those valves set inlet-to-outlet flow. Each chamber has two cylindrical pockets in the plate — one inlet stack, one outlet stack.

Location

The washer sits under the check-valve seat.

Material

Washer material usually follows the spring retainer for compatibility. Non-alloy washers can swap among themselves. Stainless washers stay with stainless retainers.

Purpose

The washer sets check-valve spring load. Some models need it and some do not because valve-plate thickness does not always match the height of the stack (retainer + spring + tetra seal + disc + seat).

Some non-alloy plates are thicker than the alloy plate for the same model. The washer takes up that extra thickness so spring compression stays the same.

Which Models Need Dampening Washers

• F/G 20 — washers on the outlet check valve, and on every non-alloy inlet retainer.
• D/M/G 03 — washers required.
• D/G 04 — current 04 seats are thicker, so washers are not used. Older 04 pumps that had washers can be retrofit with the new seats and the old washers left out.
• D/G 10 — washers on non-alloy valve plates only.
• D/G 12, 15 and 17 — alloy plates only; no washers.
• D/G 25 — washers on non-alloy plates only. Older 25s used washers on cast-iron and stainless plates too. If that is the pump you have, keep using them.
• D/G 35 and 66 — washers required.

Related Articles

• Wetted components in Hydra-Cell Pro pumps
• Check valve wear insights
• Repair kits — D, V and K
• How to repair Hydra-Cell Pro pumps