Flexible Impeller Pumps

Dry-running, self-priming, universally used pumps for a variety of fluids

Looking for a pump that is especially easy to maintain and inexpensive to run? A flexible impeller pump may be just what you need. Using a rotary flexible impeller, the pumps are capable of transferring smooth liquids, liquids with small solids and they can also convey high viscosity fluids.

Food grade flexible impeller pumps

The flexible impellers in impeller pumps are available in different flexible materials to meet the requirements of many different fluids. The impellers are off-centre inside the elliptical pump housing and as it rotates, the impeller blades flex to create a vacuum which sucks in the liquid to prime the pump. Flexible impeller pumps are self-lubricating so a minimal short dry run is possible. If the pump has already been use and fluid remains inside the pump head, a longer dry-run is possible, but not recommended.

Flexible impeller pumps are available in several sizes with various drive options and are commonly constructed from stainless-steel, aluminium or plastic. Impellers are available in various materials including NBR, EPDM, CR, FKM, FPM and TPU.

Powering an impeller pump can be facilitated with different drives: electric motors, air motors, belt drive, hydraulic motors and even with a power drill or a cordless drill with an adaptor.


A flexible impeller rotates within an eccentrically formed pump housing to create a vacuum and thus suction as the flexing of the impeller blades draws the fluid into the pump head. The fluid medium acts as a lubricant between the blades and the casing and therefore minimises friction and allows smooth transfer of the fluid. In order to avoid the possibility of damage to the pump caused by excessive dry-running, it is possible (and recommended) to install dry-run protection to each flexible impeller pump.

Flexible impeller pump suction

On the suction side of the pump, the vanes or blades of the impeller begin to straighten. The chambers between each vane enlarges and creates a vacuum which pulls the fluid into the pump.


As the impeller rotates, the fluid is positively displaced from the inlet to the outlet. Small solids & particulates are also able to be pumped freely through the pump impeller chambers.


On the discharge pressure side of the pump, the vanes of the impeller begin to flex and cause the chambers to shrink, therefore forcing the fluid out of the pump in a constant flow.

Flexible Impeller Pump Advantages


Start pumping from dry – even at a low revolutions. Impeller pumps are dry self priming up to six metres. Ideal for lifting fluids from drums or IBCs.


Depending on type and model these pumps are capable of transferring up to 1,200 litres per minute. Tanks will be drained down to the last drop.


Impellers, seals and pump housings are available in many materials. Impeller Pumps are available with AC and DC motors with various revolutions per minute.


All pumps are tested for continuous operation. Top quality materials of construction guarantee durability.


Fluids are transferred absolutely free of pulsation. Smaller amounts of air or other gaseous fluids can be handled on the suction side. Transfer soft and fragile fluids with viscosities up to 50,000 cps or with solid particles in suspension, without causing air-locks, avoids emulsifying or damaging particles.


The pumps can operate in both rotation directions which allows the easy return of excess liquid without any manual intervention and also allows easy emptying of pipes on completion of liquid transfer.


Capable of pumping fluids with a wide range of viscosities up to 50,000 centipoise. Also good on liquids containing solids. Maximum pumping temperature is 100°C. A short dry-run of up to one minute can be tolerated.


For cleaning and maintenance work, the pumps are quickly and easily disassembled. Replacement parts can be ordered individually. Low operational costs!

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