Rotary lobe pump
KRL Rubber Lobe Pump
Rubber covered lobe rotors for liquid with lumps fibre and gas.
View specifications →
2 models rubber covered rotors self priming to 8.5 m
Rubber Coated Lobe Pumps For Sludge And Liquids With Solids
Positive displacement lobe pumps with rubber covered rotors, built for wastewater, chemical and oil duties where the liquid carries lumps, fibre and hair that block other pumps.
The Range
The Same Pump Under Two Names
The KRL lobe pump and the sludge lobe pump share the design. Which name appears on your quotation depends on whether the duty is general industrial or sludge handling.
Sludge lobe pump
Sludge Lobe Pump
The rubber lobe pump specified for sludge handling duty.
View specifications →Who Buys This Line
- Wastewater plants moving thickened and dewatered sludge
- Biogas and digester operators handling gas liquid mixtures
- Chemical plants pumping liquid with suspended solids
- Contractors who need a pump that can be serviced without lifting it out
Problems It Solves
The pump blocks on rag and fibre
Large bucket geometry and a short passage through the pump let lumps, fibre and hair pass instead of wrapping around an impeller.
Downtime for maintenance is expensive
Wear parts are replaced in place by the site team without dismantling pipework or lifting the machine out of the line.
A screw pump takes too much room
The compact lobe design takes between a quarter and two thirds of the floor area of an equivalent screw pump.
Why This Line
What This Pump Does That A Centrifugal Cannot
Runs Both Ways
Operation is reversible without restriction, which lets the plant clear a blockage or empty a line without repiping.
Lifts From A Dry Line
Self priming capacity to a maximum of 8.5 metres, so the pump can pull from a sump below floor level.
Separated Sealing Cavity
The sealing cavity is kept separate and wetted, which protects the seal faces on abrasive and intermittent duty.
Application Scenarios
Duties That Suit A Lobe Pump
Sludge Transfer
Moving thickened sludge between tanks, into a dewatering unit or out to a tanker.
Gas Liquid Mixtures
Liquids carrying entrained gas, which cause a centrifugal pump to lose prime and run dry.
Chemical And Oil Duty
Cast iron or stainless bodies for chemical and oil transfer where solids are part of the liquid.
Industries Served By This Line
Selection Guide
Specifying A Lobe Pump
Describe The Solids
Particle size, fibre content and dry solids percentage matter more than viscosity for this duty.
Set Flow And Pressure
Positive displacement pumps are sized on flow and differential pressure, not on a head curve.
Choose The Body Material
Cast iron for general sludge, stainless steel where the liquid is corrosive. Rotors are rubber covered in both cases.
Plan Maintenance Access
Leave room at the cover end so the rotors and wear plates can be changed in place, which is the main advantage of this pump.
Answers
Rubber Lobe Pumps FAQ
Will this pump handle rag and hair?
Yes. It is built for liquid carrying lumps, fibre and hair, and it runs reversible so a blockage can be cleared without opening the line.
How much suction lift can it manage?
Self priming capacity is a maximum of 8.5 metres. Long suction lines reduce that figure, so send the layout with the enquiry.
Can wear parts be changed on site?
Yes, that is the point of the design. Rotors and wear parts are replaced in place by service personnel without dismantling pipework or lifting the machine.
Cast iron or stainless steel?
Cast iron suits sewage and general sludge. Stainless steel is used where the liquid is chemically aggressive. The rotors are rubber covered on both.
How does it compare with a progressing cavity pump?
It occupies far less floor space, between a quarter and two thirds of an equivalent screw pump, and wear parts change faster. A progressing cavity pump still wins on very high viscosity and steady low pulsation flow.
Engineering Notes
Guides For This Line
Maintenance Guide
Mechanical Seal Or Packing Gland How To Choose And Maintain Both
One seals better and costs more to replace. The other leaks by design and can be adjusted by anyone on site. Choose against the liquid and the maintenance team.
Read the guide →
Design Guide
Sizing Submersible Aeration For A Treatment Basin
Oxygen demand sets the capacity, basin geometry sets the number of units, and the lifting arrangement decides whether maintenance needs a shutdown.
Read the guide →Tell Us What Is In The Liquid
Solids size, fibre content and dry solids percentage decide the model. Send those with the flow and we will quote the set.