Three Screw Pumps

Working Principle

  • One Power screw and two Idler screws running in the three precision bores in the housing or liner
  • Profiled Screws form a liquid tight seal between the threads
  • As the screws rotate, cavities are formed, where liquid gets trapped and conveyed from suction chamber to discharge chamber
  • The power rotor does not rotate the idlers. The hydraulic forces acting on screw flanks turn the idlers without torque thus reducing the friction
  • The idlers simply roll over the root diameter of power screw and float freely in housing/liner bores
  • A balance piston on Power rotor takes care of axial thrusts
  • Ball bearing is only for axial positioning of Rotor and safer operation of mechanical seal


  • High Reliability & long Service life
  • Lowest Total Cost of Ownership
  • High Efficiency
  • Self Priming
  • Lowest Maintenance Cost
  • Ease of Installation & Commissioning
  • Smooth Operation
  • Low Noise & Vibration
  • Excellent Suction Lift
  • Flexibility of Use and Wide range of Liquids and Viscosities
  • Wide range of Flows and Pressures
  • High Speed Capability
  • Axial Flow – no churning, chewing or shearing
  • Hydraulic balancing of forces to eliminate need for any bearings


  • Loading
  • Unloading
  • Transfer
  • Forwarding
  • Fuel Firing
  • Sealing
  • Lubrication
  • Cooling
  • Governing
  • Jacking Oil
  • Circulation

Maximum Performance Data


upto 2835 lpm

Diff. Pressure

upto 100 bar

Operating Parameters


From 3 cSt to 50,000 cSt

Fluid Temperature

upto 200 deg. Centigrade

Material of Construction

Casing Options

Cast Iron / Cast Steel / Fabricated / SG Iron

Casing Insert Options

Aluminum / No Casing insert


Alloy Steel

Sealing Options

Gland Packing / Mechanical Seal

Construction Features

Bearing Options

Internal / External ball bearing

Jacketing Options

Front Cover / Gland Cover / Casing / Foot

Mounting Options

Horizontal Foot / Horizontal Flange / Vertical Pedestal / Vertical Tank

Relief Valve Options

Built-in / Line Mounted