ZWL Direct-Coupled Self-Priming Sewage PumpCold-Weather & Freeze Protection for a ZWL Pump
A self-priming pump holds liquid inside — which can freeze in winter. Here’s how to protect a ZWL pump in cold weather so it primes when you need it.

POME is hot, acidic, oily and high in solids. A high-temp stainless ZWL self-priming pump moves it. A practical guide for palm oil mills in SE Asia.
| Flow Rate | 8–800m³/h |
|---|---|
| Head | 10–80m |
| Power | 1.5–75kW |
| Inlet / Outlet Diameter | DN25–DN300 |
| Material | Cast Iron,SS304,SS316L |
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Palm oil mill effluent — POME — is one of the toughest wastewaters a pump can face, and mills across Malaysia, Indonesia and Thailand move enormous volumes of it. It’s hot (often 80–90°C fresh from the process), acidic (around pH 4–5), oily, and thick with fibre and suspended solids. Pick the wrong pump and it clogs, corrodes or cooks. Here’s how a ZWL direct-coupled self-priming sewage pump is configured for POME.
Two things drive the specification:
So a typical POME pump is a high-temperature stainless ZWL.
POME carries palm fibre, nut and shell fragments, sludge and free oil. The ZWL’s non-clog passage clears solids up to about 60% of the port diameter and fibre up to five times it, so the fibrous load flows through. Being self-priming and dry-mounted, it draws from the cooling pond, ponding system or effluent pit on its own — no foot valve, primes itself after the first fill — and the big DN200–DN300 models handle the high volumes a mill produces.
Tell us your POME temperature, pH and flow, and we’ll spec the right high-temp stainless ZWL.
ZWL Direct-Coupled Self-Priming Sewage PumpA self-priming pump holds liquid inside — which can freeze in winter. Here’s how to protect a ZWL pump in cold weather so it primes when you need it.
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