Viscous Monoscrew Pumps


The Monoscrew pumps  are rotating positive displacement pumps. With a positive displacement pump , the mechanical energy produced by a motor, is  transferred via a displacement unit , being either a eccentric screw or a rotor ; in the form of pressurised energy, over to the liquid residual in the displacement area. Since the movement of the displacement unit is  rotary one, we talk of rotating positive displacement pumps.

Their function combines the advantages of centrifugal pumps and oscillating reciprocating pumps. The mono screw pumps consist of a rotating element, the displacement unit; being either an eccentric screw or a rotor; and also a static element , the stator.


The rotating part, the rotor, has the form of a round rapid motion spiral spindle with a large pitch. The static element, the stator, is in the shape of a double- lead interior screw, thereby enabling a double pitch of the rotor.

Consequently there are cavities between the rotor and stator which always have the same size during the rotation of the rotor.

If the rotor is made to rotate, then these cavities ; and consequently the substances to be conveyed; are shoved in  a screw- like manner from the suction to the pressure side. The rotors of the PUMPAID mono screw pumps possess a relatively large eccentricity with respect to the pitch.


 Whereupon it is possible to convey large solid objects through the pumps without damage. Furthermore the construction length of the pump is reduced to a minimum. The relatively small rotor surface with minimum friction permits a low performance from the pumps. 

In order to transfer this movement from the central one of the drive onto the rotor it is necessary to have a universal joint- propeller shaft with two compensating knuckle joints. These universal-joint propeller shafts connect the drive and the rotor. It is not necessary to have another bedding for the rotor other than in the stator.


The watertight line between the rotor and the stator is specified for each rotor setting. This means that the pressure area is always separated from the suction area. The mono screw pumps can withdraw themselves and are thereby regenerative. This self-priming capability is achieved without the assistance of  fluids. 



* Casing & Covers : Pressure tested graded cast iron.

* Gears & Shafts : Carbon steel-spur or Double helical gears

* Bearings : Antifriction or Bush Bearings.

* Sealing : Lip type or Mechanical seal. Gland packing for Abrasive or highly        
   viscous liquids.

* Testing : Each pump tested for its performance.

   Tests can be offered to any inspection authority.

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