Two Screw Pumps

Two screw pumping technology was invented by William Quimby of New Jersey, U.S.A in the year 1894. He founded a manufacturing unit of two screw pump which was eventually acquired by Warren Pumps an associate company of Tushaco Pumps in the year 1950.

Working Principle

A pair of specially profiled screws, machined integral from solid stock and well supported on antifriction bearings run in precision bored interchangeable casing liners. Each screw set has one RH and one LH screw engaging with a similar but opposite hand screw pair.

A pair of hardened and profile ground timing gears synchronize the screws to maintain a small but positive clearance between the flanks thus ensuring no metal to metal contact. The pumps can, therefore, run dry for sometime without any damage. This unique feature enables to run the pump even dry and handle fluids that do not have enough lubricating value and also very low or high viscous products. Consequently, since there is no metal to metal contact; wear and tear is reduced to the minimum, ensuring extremely long service life. With two pairs of screws running in the same casing, the internal velocities are very small - consequently the NPSH R is practically the lowest even when the pumps run at motor speeds and while handling viscous products. Opposed screw pitches totally eliminate axial thrusts. Relatively small diameters of screws enables the pump to operate at high speeds directly coupled to prime movers - without the need for speed reducers even while handling high viscous fluids. The seals are always under suction pressure, thus making use of simple, inexpensive seals. The axial flow is without turbulence, rotation, churning, chewing guarantees gentle handling of products. Noise and vibration levels are the lowest. Positive clearance between running parts makes it easier to construct the pump in different materials safely, especially in stainless steel, without the fear of seizing. Thus a variety of fluids can easily be handled by selecting the right materials of construction. View Catalogue


Typical Pumped Media

Crude Oil, Additives, Paraffin, Base oils, Petroleum products, Bitumen, Polyester, Fuel oils - all grades, Residues, Lubricating oils - all grades, Soap, Vegetable oils, Molasses, Vanaspati, Sugar syrup, Fruit Juices, Bilge

Typical Applications

Loading & unloading of fuel oil and other products from: Railway wagon rakes, Truck tankers, Barges, Ships and Tankers, Bulk cargo handling

Process pumping of high viscous products such as bitumen, molasses, soap and similar products

Long distance pipeline pumping of viscous products

Typical Industries

Oil & Gas, Power Generation, Marine & Navy, Petroleum refineries, Terminals, Depots, Oil blending stations, Steel plants, Fertilizer industries, Petrochemical plants, Carbon black, Food & Beverages, Paper and Pulp

Maximum performance data

  • Capacity : upto 15000 lpm
  • Diff. Pressure : upto 120 bar

Maximum Operating parameters

  • Viscosity : 1 to 50000 cSt
  • Fluid Temperature :upto 350 °C

Material of Construction

  • Casing options : Cast Iron / Cast Steel / Fabricated Steel / Fabricated Stainless Steel
  • Screw set option : Carbon Steel / Stainless Steel
  • Liner options : Cast Iron / Bronze / Stainless Steel
  • Sealing Options : Gland Packing, Mechanical Seal

Construction Features

  • Bearing location : External / Internal
  • Jacketing options : Casing / Foot / Cover / No jacketing
  • Mounting options : Horizontal foot / Vertical pedestal / Vertical tank
  • Relief valve options : Built-in / Line mounted


Relief valves, base frame, coupling, coupling guard, companion flanges, pressure gauges, electric motor, variable speed drives, etc.

Pump mounted on a base plate with above accessories as a ready to install system can be supplied

Salient Features

  • Positive clearance between rotors
  • No metal to metal contact between rotors
  • Dry running capability
  • Negligible wear over years
  • Axial smooth steady flow
  • High speed running
  • Pulsation free output
  • Negligible vibrations
  • Insensitive to varying viscosities
  • Long maintenance free service
  • Lowest NPSHR
  • Shaft sealing at suction pressures
  • Axial thrusts completely eliminated
  • Interchangeable liner
  • Adaptability of various MOC