ZWL Self-Priming Pump for Tannery & Leather Wastewater

Few wastewaters are as hard on a pump as tannery effluent. It swings from strongly alkaline (liming, unhairing) to acidic (pickling, chrome tanning), it’s loaded with hair, flesh scraps, lime sludge and hide trimmings, and it carries sulphides and chromium. Cast iron doesn’t stand a chance in it for long. For a tannery, a stainless steel ZWL direct-coupled self-priming sewage pump is the realistic choice.

The chemistry is the deciding factor

Because a tannery’s streams run across such a wide pH band, the wetted material has to cope with both acid and alkali. The stainless ZWL is rated for roughly pH 2–13, versus cast iron’s narrow pH 6–9 — which is why it survives where an ordinary sewage pump corrodes through in weeks. If you’re replacing pumps constantly on a beamhouse or tanning line, the material is almost always why.

And it still clears the solids

Tannery liquor isn’t just aggressive, it’s full of stuff — hair, fleshings, lime and hide bits. The ZWL’s non-clog passage clears solids up to about 60% of the port diameter and fibre (hair) up to five times it, so that load flows through rather than matting on the impeller. Being self-priming, it mounts on dry ground above the pit, primes itself after the first fill with no foot valve, and stays accessible for the regular cleaning tannery sludge demands.

Specs for tannery effluent

• Material: stainless steel (pH 2–13) — cast iron is not suitable here
• Passable solids: up to ~60% of port diameter; fibre (hair) up to ~5×
• Flow rate: 8–800 m³/h
• Head: 10–80 m
• Self-priming height: 4.5–5.5 m

Tell us the stream (beamhouse, tanyard or mixed) and its pH swing, and we’ll spec a stainless ZWL that lasts.