ZWL Self-Priming Pump for Chemical & Corrosive Media

With chemical media, the pump body is everything. Get the material wrong and the most powerful pump on the market corrodes through in weeks. So before anything else: a stainless steel ZWL direct-coupled self-priming sewage pump is the version that belongs on corrosive duty — the cast iron model is for neutral sewage, not acids.

Chemistry first

The stainless ZWL widens the medium tolerance from cast iron’s roughly pH 6–9 up to about pH 2–13 (some builds 1–14), so it handles the acidic and alkaline streams that ordinary sewage pumps can’t touch. It also runs media up to around 80°C as standard, and to about 200°C on special build — useful for warm process liquids. There’s an explosion-proof motor option for volatile environments, too.

One honest caveat we always give: “corrosion-resistant” only means resistant to *your* specific chemical at *your* concentration and temperature. Tell us exactly what the medium is and we’ll confirm the material actually suits it.

Not just liquid — suspensions too

What makes the ZWL more than a plain chemical pump is that it also handles the *solids*. Corrosive process streams are often loaded with particulate and fibre, and the ZWL’s non-clog passage clears solids up to about 60% of the port diameter and fibre up to five times it. Add self-priming operation — no foot valve, primes itself after the first fill — and it suits chemical sumps and transfer duty where the liquid is both aggressive and dirty.

Specs for corrosive duty

• Material: stainless steel (pH 2–13; cast iron 6–9 for neutral media only)
• Medium temperature: ≤80°C (to ~200°C special)
• Motor: standard or explosion-proof
• Flow rate: 8–800 m³/h
• Head: 10–80 m