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Product code: Boyser LB-S Rotary Lobe Pump

Boyser LB-S Rotary Lobe Pump

Pump Type - Lobe

Max Flow Rate - 40M³H

Max Head - 100M

Pump Materials - AISI304, AISI316, AISI316L, EPDM, NBR

Max Temp - 120°C

Max Viscosity - 100,000 cst

Max Solid Passage - 38mm

Self Priming - Y

Inlet/Outlet Sizes - 50mm to 80mm

Drive - AC Electric, Bareshaft

Max Suction Lift - 6M



Boyser LB-S Rotary Lobe Pump

The Boyser LB-S range of rotary lobe pumps are positive displacement and designed for a wide range of applications involving fluids that are low viscosity, high viscosity, solids laden and shear sensitive. The flexibility of manufacturing these pumps with either AISI-420 or AISI-316 stainless steel casings and either rubber or metal lobes enables this range to be used for both industrial and hygienic related purposes.

The lobe design creates a gentle pumping action for the handling of shear sensitive fluids and large solids such as grapes and olives. This range is self-priming, compact, reversible and creates minimal pulsations, making it extremely versatile and the ideal pump for so many situations.

Larger pumps in the LB-S range can produce flow rates up to 40m³/hr, pressures up to 10 bar and can allow the passage of solids up to 38mm in diameter. The variety of sealing options means these can be customized to accommodate liquid temperatures up to 120°C and to allow dry running indefinitely.

Maintenance and cleaning are simple due to a removable front plate allowing easy access to the internal components and mechanical seal. The ability to install heavy duty cartridge mechanical seals and replaceable internal wear plates means abrasive and aggressive fluids can be handled without concern of the complete pump wearing prematurely.

Common applications and fluids

·         Food: Wine, Olive Oil, Vegetable Oil, Molasses, Pressed Olive Waste, Fermented Grapes, Glucose, Tomato Concentrate, Chocolate.

·         Industrial:  Sludge, Slurries, Manure, Effluent, Crude Oil, Glue, Inks, Paint, Fuel oil.

·         Mining: Bentonite, Ceramic Slips, Calcium Carbonate.

·         Oil & Gas: Seawater, Crude-Oil products, Oily Sludge, Marine spills, Mud.

·         Pharmaceutical: Detergents, Surfactants, Glycerine.

·         Wastewater: Membrane Bioreactor (MBR) Filtration, Effluent, Sewage.



·         Custom inlet and Outlet Connections - Gooseneck connections are available ensuring the pump suction port remains fully filled with fluid. This ensures a vacuum can be created more easily, even should the lobes become heavily worn. Gooseneck pipework also ensures the conveying of gas bubbles which may form within a liquid. Vertical outlet connections allow pumps to remain compact in design. Connections can be flanged, or according to hygienic / pharmaceutical requirements for speed of cleaning or removal from pipework.

·         Pressure Control – Units can be fitted with a Pressure Switch preventing pump operation at pressures likely to damage the system or pump. Alternatively, a torque limiter detects when the working action of the pump becomes strenuous preventing the pump from generating excess pressure. They can also be used to prevent pumps from dry running.

·         Bypass – If pressure control is undesired, units can be configured with bypass valve pipework connected to pumps, allowing fluid to recirculate back to the pump inlet should pipework become blocked.

·         Modular Configuration - Units can be baseplate mounted or mounted on trolleys allowing portability and complete with control panels allowing easy control of flow.

·         Hopper with auger feed screw - Allowing the pumping of high quantities of suspended solids, and ensuring fluids are fed into the pump for transfer.


Product summary

·         Self-priming up to 6 metres vertically

·         Reversible - Allowing versatility across applications, and recovery of fluid from hoses.

·         Wear-resistant – Casing is manufactured in Stainless Steel from a single block. The pump head also contains wear plates, allowing cost effective replacement as the casing is not worn.

·         Available with several sealing options – including cartridge seal and single mechanical seal for high temperatures and indefinite dry running.

·         Continuous Flow - The non-pulsating lobes produce a continuous linear pumping motion.

·         Low Cost and Easy maintenance – Pump Parts are accessed by removal of the front cover plate, allowing easy access without removal from the baseplate.

·         Large solids passage – Up to 38mm in diameter.

·         Rubber coated or metallic lobes - Allowing utilisation with aggressive chemicals, or in hygienic applications. Available in NBR (food grade), EPDM, VITON and stainless steel.

·         Compact design.

·         Intermediate Chamber – To eliminate the possibility of cross contamination between lubricants in the gear box and any liquid being pumped, a gap between the two housings is present. Should seal failure occur in either the gear box or pump head, fluid enters the space and can be easily seen rather than cross contaminate.

·         Available with industrial or sanitary connections including flanged, DIN 11851, SMS, MACON, RJT and tri-clamp.

·         Available with electric or hydraulic motor.

Read more about Lobe Pumps in our guide


As standard, rotary lobe pumps have limited dry running capability and the internals will begin to incur damage after short periods. We can however install our lobe pumps with a special mechanical seal system that enables the pump to run dry indefinitely. The mechanical seal requires lubrication and cooling while the pump is operating. Without the presence of fluid, the mechanical seal will overheat and crack, and this may cause the pump to leak and fluid to enter the motor. There is also the possibility that the motor will burn out. The rubber lobes may also melt or deform even after short periods of dry running. Our advice is to ensure that the pump always has access to fluid while running, the vessel or sump on the inlet side of the pump must never run out of fluid while the pump is active. Level sensors or a float switch can be installed in the fluid chamber ensuring that the pump is turned off in the event there is no fluid. Another way of protecting the pump is to fit a dry running device, this will turn the pump off if it detects that no fluid is entering the pump. If you think that dry running is inevitable, then please speak to us and we will select the most appreciate pump and sealing system for you.
A pump must be primed in order to operate correctly, this means that the pump casing and inlet pipe must be filled with fluid and the air removed before operation. This needs to be done manually by the pump operator for a non-self-priming pump each time the pump is used to avoid damage from dry running. A self-priming pump removes these issues by completing the priming process automatically. The air is removed from the inlet pipework and pump casing when the pump is activated. Self-priming pumps are particularly useful for installations with a suction lift on the inlet side of the pump, the pump will draw the fluid up the pipework by creating a vacuum and removing any air that is present. In ideal conditions, a self-priming pump can lift fluids up to around 6m on the inlet side, however this figure is affected by fluid viscosity, pipework bore and other installation conditions, therefore this figure can be much lower from case to case. Allowances must also be made for wear and tear; suction lift capabilities will be much lower for older and worn pumps.
Please be aware that the figures displayed relate to the largest pump from this range of products, not specific models. For the LB-S range, the maximum solids handling for the largest model is 38mm in diameter. For details on solids passage for specific models, please refer to datasheets or contact a member of our sales team.
Please be aware that the figures displayed relate to the largest pump from this range of products, not specific models. For details on viscosity for specific models, please refer to datasheets or contact a member of our sales team.
A clear picture of the pump system is required to make an accurate selection. The main pieces of information required include; a description of the application, bore of pipework, the fluid, viscosity, size and type of solids, flow rate and pressure/head. With these pieces of information, a pump can be sized correctly to ensure it delivers the required flow rate and pressure and that is also operates at its best efficiency point to lower lifetime costs. Viscosity is a major factor when selecting the correct motor speed. A full speed pump will not transfer high viscosity fluid correctly, whereas a slower speed pump will have a much gentler pumping action. Knowing if the pump is running intermittently or continuously also allows the correct motor speed to be selected. For instance, a pump running continuously 24/7 will require a slower speed motor rather than a full speed motor. Running the motor slower and oversizing the pump will reduce wear of the motor and the pump, therefore lowering maintenance costs during their lifetime.
Firstly, always check the compatibility of the materials available against the fluid being pumped. The main materials to check are the pump casing, lobes, o-ring and mechanical seal. It may be that more than one material is suitable for your fluid and selection could be based on the application type. For instance, different rubbers and metals have better resistance to higher temperatures and abrasion, and others are better for hygienic applications and CIP. Please consult our sales engineers for the correct material selections.
Our rotary lobe pumps can be supplied with a wide range of food grade and non-food grade connections, including; DIN, BSP Male and Female, Triclover, SMS, RJT, Friederich, Garolla and Macron.
It is always best practice to clean the internals of the pump after each use, especially when handling food and beverage products. A standard cleaning process involves running clean water through the pump for 1-2 minutes and then emptying the pump and pipework of all fluid. When handling food grade products, refer to the standards of your industry. This typically involves CIP (Clean in place), flushing the pump for a set period of time with hot water or a water and chemical mixture. Always ensure that the chemical used is compatible with the pump body, lobes, o-ring and mechanical seal materials. Also ensure not to get any electrical components wet and to use glycerine oil for impeller lubrication. A benefit of our LB-S and LB-M rotary lobe pumps in that the front cover can be easily removed for access to the internal components for cleaning.


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