Slurry Pumps

What these slurry pumps are for

The pumps in this category handle water-based slurry: muddy water, silt, sand, sludge and wash water with granular solids. They are used in civil engineering and building works, quarries and aggregate yards, settling tanks and lagoons. Solids that settle out are the main problem, which is why the heavy duty submersibles here use an agitator to lift them back into suspension.

They are not designed for raw sewage with rag and fibres, which needs a vortex or cutter pump from our sewage pumps range. Thick livestock slurry with straw and bedding normally needs specialist farm slurry equipment, so talk to us about the liquid before buying.

Slurry pumps we stock

The JST KZN series is our main slurry pump. Each model has a built-in agitator at the inlet, a high chrome iron impeller, agitator and wear plate for abrasion resistance, and double silicon carbide mechanical seals running in an oil chamber. Models run from 3 inch to 6 inch outlets and 3.7 kW to 22 kW, passing granular solids from 20 mm up to 35 mm. All are 400v three-phase.

Other options in this category:

• JST KZN-H and KZN-L heavy duty 400v industrial submersibles from the same family
• JS JST KB heavy duty 400v industrial submersibles
• Koshin KTH petrol engine trash pumps with hi-chrome impellers, for dirty water with solids up to 30 mm where there is no three-phase supply
• GMP Electric Surface Trash self-priming pumps that sit outside the pit

Sizing and running a slurry pump

Published pump curves are measured on clean water. Slurry is heavier and thicker, so a pump moving it will deliver less flow and head than the curve shows. Allow a margin when sizing, especially on long or uphill discharge runs. Our guide to pump sizing walks through the calculation.

• Stand submersibles on a firm base so they do not bury themselves in settled solids.
• Keep discharge velocity up so solids do not drop out in the pipe. Oversized pipe can block.
• Flush the pump and pipe with clean water after use.
• Check the wear plate and impeller regularly on abrasive work.

For clean or lightly dirty water, a lighter dewatering pump or dirty water pump will do the job at lower cost.

Frequently asked questions

Can these pumps handle farm slurry?

They suit agricultural waste water and dirty yard water with fine, granular solids. Thick livestock slurry containing straw, bedding or fibre needs specialist farm slurry equipment. If you are unsure which yours is, contact AES with a description of the liquid before ordering and we will tell you whether one of these pumps will cope.

What does the agitator on a slurry pump do?

The agitator sits at the pump inlet and stirs settled sand, silt and sludge back into suspension so the pump can draw it away. Without one, solids build up around the inlet and the pump ends up moving mostly water while the sludge stays behind.

Do slurry pumps need a three-phase supply?

The JST KZN heavy duty submersibles are 400v three-phase only and cannot run on single-phase power. If you have no three-phase supply, a petrol engine trash pump such as the Koshin KTH is the usual alternative for dirty water with solids.

Can a slurry pump be used for sewage?

No. Slurry pumps are designed for granular solids such as sand and grit, not the rag, wipes and fibres found in raw sewage, which wrap around the impeller. Use a vortex, grinder or cutter pump from our sewage pumps range for foul water.

What solids size can a slurry pump pass?

It depends on the model. The JST KZN range passes granular solids from 20 mm on the smallest model up to 35 mm on the 11 kW models and above. The Koshin KTH handles solids up to 30 mm. The KZN figures apply to grit and sand, not rag or fibres.