What material impellers do I need?

Ensuring compatibility with the fluid being pumped is a vital part of flexible impeller pump specification to avoid swelling, erosion and even melting of the impellers. Our Liverani impellers are available in Natural Rubber, Neoprene, NBR, EPDM and Silicon. Upon disclosure of the fluid you are handling we will establish the best solution. Or view our chemical compatibility table here.

Are Liverani flexible impeller pumps food grade?

Yes. The pump is constructed of a 316 Stainless Steel pump head and the impellers are available in food grade NBR or EPDM. They can also be supplied with food safe Tri-clamp fittings to meet ISO 2852 and with Stainless Steel motor enclosure on request.

Can flexible impeller pumps run dry?

Unfortunately not! The fluid acts as a lubricant and coolant as the pump runs, so as well as risking the impeller melting, the mechanical seal could crack and result in leaking if it overheats. Consider a dry run protection device or float switch if there is risk of this happening.

Where are flexible impeller pumps used?

Flexible impeller pumps are a relatively low cost solution compared to other pumps able to handle aggressive fluids, solids and viscous liquids. They are however limited in their pressure capabilities, so are usually reserved for more steady duty requirements.

Are flexible impeller pumps reversible?

Yes. Being able to operate in both directions makes flexible impeller pumps ideal for tank to tank transfer as well as returning excess liquid out of the pipework when transfer is complete.

Are flexible impeller pumps able to handle solids?

Yes. The impellers are made of a supple rubber type material able to bend around soft solids without damage or jamming.

Are flexible impeller pumps self priming?

Yes! Thanks to the nature of the flexible vanes meaning that they maintain a tight seal with the internal pump walls they are ideal for where suction lift is required.

What information do you need to quote me for Liverani pump parts?

To ensure you get the correct Liverani pump spares, we need to identify the exact pump model you have. Please advise us of the model number and serial number (referred to as Commessa) which can be found on the pump label which is usually on the top of the pump body.

I need a Liverani pump parts distributor near me, can you help?

Castle Pumps can supply all Liverani pump parts detailed on the spare parts list including impellers, mechanical seals, casing and o-rings.

Do you supply any accessories for Liverani impeller pumps?

Liverani pumps are available with additional accessories including inverters for variable speed, trolley for portability, level sensors, control panel, remote control operation and bypass valve for nozzle dispensing.

Liverani GR Flexible Impeller Pump

Abrasive Solids & Food Grade Pump

Key Specifications
Max Flow Rate	690lpm
Max Head	20M
Max Temperature	100°C
Max Viscosity	50,000 cP
Solids	25mm
Size	1” to 4"

Datasheet

Enquire now about this product

The Liverani GR Flexible Impeller Pumps are a range of belt driven models, able to handle a wide variety of fluids. This is a cost effective means of operating the flexible vane pumps at different speeds without the use of an expensive gearbox. Furthermore, when using GR flexible vane pumps on viscous or solids laden fluids the belt drive will protect the motor from overloading by slipping, therefore avoiding potentially lengthy and costly downtime.

Flexible impeller pumps are a very versatile in the applications that are suitable for thanks to several design benefits. Firstly, thanks to their supple vanes they are able to handle not only clean, light fluids, but also viscous, solid laden slurries. Secondly, the multiple materials the impellers are made out of mean they are compatible with many fluids e.g. NBR for fats and fuels, EPDM for chemicals and hot fluids and natural rubber for water based liquids. Flexible vane pumps with EPDM and NBR impellers are able to be supplied with FDA Certification, making them a popular electric food grade pump solution. Their low shear operation also makes the ideal for handling delicate fluids that can be altered by other pump designs.

Flexible impeller pumps are renowned for their dry self-priming capability, making them ideal for applications where good suction lift capacity is needed such as the emptying of tanks, sumps and other containers. The GR flexible vane pumps are widely used in transferring, filling & emptying applications, but when used in conjunction with a carrying handle and their integral on/off reversing switch they are also a very reliable utility pump solution popular for tank to tank transfer.

For more information on the design of flexible vane pumps and how they operate, read our guide.

Features of the GR Series Flexible Vane Pump:

Belt driven flexible impeller pump
Gentle, pulsation free pumping mechanism ensures the handling of shear sensitive liquids.
Solids passage capability - 10mm (MINOR), 15mm (MAJOR), 25mm (MAXI)
Dry self priming up to 6m without the need of a non return valve.
Pumps can be operated in either direction via a reversing switch mounted on the pump.
Specific models are available with 2 speed operation, controllable via a rocker switch on the terminal box.
Pump head can be rotated and installed in a range of positions for versatility.
Wide range of connection types available including DIN, BSP Male & Female, Triclover, SMS, RJT, Friederich, Garolla, and Macron
Optional Stainless Steel AISI 304 Pipe Fittings for easy installation of the pump into existing pipework
Flexible vane pump heads are SS304 as standard. SS 316 available on request,
NOTE: units are supplied with Garolla connections as standard with hose fittings, clamps and seals included.
Unit can be supplied with or without a control panel as well as fitted with dry-run protection .
Manual by-passes (MAJOR & MAXI) for manual adjustment of the flexible impeller pump capacity available on request.
Automatic barrel filling kits are available complete with stainless steel nozzle, non return valve & pressure switch.
Accessories include inverter drive for variable speed operation, dry run protection, pressure switch for automatic pumping, level sensors, remote control & radio operation.
Spring loaded by-pass for the MINOR for manual adjustment of the capacity and use with a nozzle.

The beauty of the GR flexible impeller pump is it's versatility. Thanks to the following features it is an option that can be applied to many application requirements.

Handles solids up to 25mm – Supple impellers bend to pass viscous fluids and slurries up to 50,000 CP and solids without damage to the pump
Applies low shear – Ideal for delicate, shear sensitive fluids that can be damaged or altered by other pump types such as cream that gets thicker when whipped.
Reversible operation – Allows cleaning solution to be ran through after use for hygienic pump applications, and tank to tank transfer applications.
FDA approved – EPDM and NBR impellers with FDA certification for food grade pump assurance. Stainless sanitary enclosures and Tri-clamp couplings available.
Smooth, steady pumping – Provides a consistent flow ideal for dosing ingredients, chemicals and process fluids and filling finished product into packaging.
Self-priming up to 6m – Enables the emptying of tanks and drums without a non-return valve or regular manual priming being required.
Various mounting positions - Allows for versatile installation to fit the pipework at hand
Various accessories available - Trolley for portability, bypass valve for nozzle dispensing, control panel, variable speed drive, level sensors and dry run protection

Flexible impeller pumps are a versatile design of pump for relatively low pressure applications, mainly with thanks to their impellers being produced in a wide range of materials for fluid compatibility including food grade applications. As the impellers are made of a supple, rubber type material that is able to bend, flexible vane pumps are also able to handle viscous fluids and those with solid content without causing damage. They also apply little shear to the pumped medium, making them suitable for shear sensitive fluids and their ability to be operated in reverse makes them ideal for tank to tank transfer. These design benefits make them suited to many applications including:

Marine Applications	Industrial Applications
Contaminated bilge water pumping Oil and lubricant transfer Black and grey water pump Sludge and slurries Fish waste pump Tank to tank seawater transfer	Food processing and transfer Dairy products Brewery and distilleries Chemical pumping Waster water pump containing solids Oil and lubricants Viscous fluids, sludges and slurries Soaps, creams and gels Paints, glues and detergents

Material options for the GR flexible impeller sanitary pump:

Description	Stainless Steel AISI 304	Stainless Steel AISI 316	Nitrile (NBR)	Natural Rubber (NR)	Neoprene (CR)	EPDM	Silicon (VMQ)	St. St. / Graphite / NBR	Tungsten Carbide / NBR	Tungsten Carbide / Viton
Part List
Pump Body	X	X
Impeller			X	X	X	X	X
Mechanical Seal								X	X	X

** NOTES

1.Changes in Mechanical Seal Materials are at cost. All pumps are supplied with Ceramic / Graphite / NBR as standard.

2.Changes in Impeller Materials are Free of Charge. All pumps are supplied with Natural Rubber Impellers as standard.

3. EPDM and NBR impellers are available with FDA certification

FAQs

Flexible impeller pumps are part of the positive displacement pump family. They consist of a rotating rubber impeller with supple vanes attached. As the casing is smaller than the vanes, they must bend and then straighten as the impeller turns to conform to shape of the pump internal walls. The vacuum created push the fluid round from the inlet to the outlet.