Small ZWL Self-Priming Pumps: DN25–DN50 Range

Not every job needs a big pump. For light drainage, small workshops, farms and building services, the small end of the ZWL direct-coupled self-priming sewage pump range does the work without wasted power or footprint. These are the DN25 to DN50 models.

The models in this class

The small ZWL units run on modest 1.5–3 kW motors and cover low-to-moderate flow with useful head:

• 25ZWL8-15 — 8 m³/h at 15 m, 1.5 kW (DN25)
• 32ZWL10-20 — 10 m³/h at 20 m, 2.2 kW (DN32)
• 40ZWL10-20 / 40ZWL15-30 — 10–15 m³/h at 20–30 m (DN40)
• 50ZWL10-20 / 50ZWL20-12 / 50ZWL15-30 — 10–20 m³/h at 12–30 m (DN50)

They pass solids up to about 60% of the port diameter — so even the small DN50 clears roughly 30 mm solids and 250 mm fibre — which is plenty for light sewage and dirty water.

Where they fit

These suit basement and building drainage, small workshop effluent, light farm and pond duty, and any transfer job where you don’t need big volume but still want the self-priming, non-clog convenience: no foot valve, primes itself after the first fill, compact and easy to install. Cast iron is standard; stainless steel is available where the liquid is corrosive.

Small ZWL range (DN25–DN50)

• Flow rate: 8–20 m³/h
• Head: 12–30 m
• Motor power: 1.5–3 kW
• Self-priming height: 4.5–5.5 m
• Material: cast iron or stainless steel