Schego M2k3/ws3 Diaphragm Set

Description

Schego M2k3/ws3 Diaphragm Set — Replacement membranes for Schego M2K3 and WS3 air pumps

Every stroke of a membrane pump flexes the same small disc, and in an M2K3 that stroke happens tens of thousands of times a day. Schego M2k3/ws3 Diaphragm Set (SKU: SH742) is the replacement diaphragm set for the Schego M2K3 and WS3 air pumps. The diaphragm is the membrane that turns the arm’s vibration into moving air, and one set is listed for both models, which share their pump head. When it hardens, cracks or loses its flex, the pump delivers less air than its rating even though it runs normally.

The M2K3 is listed at 300 L/h with no head and 260 L/h at 0.5 m, with a single outlet and a screw regulator. The WS3 is the higher-pressure version: Schego lists it at 350 L/h, 5 W and a pressure of at least 3 m of water column, with a regulator and a 1 m cable, for decorative water columns and protein skimmers. A skimmer pump works harder against depth, so a tired diaphragm shows up there first. The job itself is simple: turn off the pump and disconnect the air filter, remove the pump head carefully, take off the old film and insert the new one, paying attention to the direction, then reassemble and check operation. The maker does not publish diaphragm dimensions, so the old film is the reliable guide to the right way round. If the chamber is also dirty or cracked, the air chamber and diaphragm kit (SH743) is the better purchase.

Usage & Application

When to Use

• Loss of air volume: The M2K3 or WS3 runs but no longer fills its air stones or skimmer.
• Pressure applications: WS3 pumps feeding skimmers or water columns that start to struggle.
• Stiff or cracked membrane: A diaphragm inspected during service shows its age.
• Routine rebuild: A scheduled change on pumps in continuous service.

Installation & Replacement Guide

• Stop and disconnect: Turn off the pump, unplug it and disconnect the air filter.
• Remove the head: Carefully take off the pump head to reach the diaphragm.
• Swap the film: Take out the old diaphragm and insert the new one, paying attention to its direction.
• Rebuild and check: Reassemble the pump and confirm that it runs and delivers air.

Product Specifications & Highlights

Key Features

• Two models: Listed for both the M2K3 and the WS3.
• Directional fitting: The new film must be seated the right way round.
• Restores delivery: Brings back the air volume of a worn pump.
• Diaphragm only: The chamber is a separate part (SH749) or included in the kit (SH743).
• For pressure pumps: Matters most on the WS3, designed for 3 m of water column.

Product Details

• Brand: Schego (Schemel & Goetz, Germany)
• SKU: SH742
• Barcode (GTIN/EAN): 4005256007427
• Product Type: Spare Parts > Air Pump Diaphragm
• Fits: Schego M2K3 and WS3 air pumps
• WS3 Output: 350 L/h, 5 W, at least 3 m water column (Schego)
• M2K3 Output: 300 L/h at 0 m; 260 L/h at 0.5 m head
• Companion Parts: Air chamber and diaphragm kit (SH743); chamber gaskets (SH746); pump chamber (SH749)
• Target Environment: Freshwater and marine aquariums and skimmers aerated by Schego M2K3 or WS3 pumps