Twin Screw Pumps

The working principle of Roto gear timed Dual-Flow Twin Screw Pumps is dependent on the rotation of two screw spindles in closed compartment. Wherein a pre-defined clearance is maintained between the screw spindles as well as between the outside diameter of the screw spindles and the bore of the casing/liner in which the screw spindles are located. Each half of the screw spindles is left-handed and right-handed. Thus when the spindles start rotating, driven by a pair of timing-gears located at the end of the screw spindles, the liquid is drawn towards the end of the screw spindles and entrapped between the bore of the pumping compartment as well as the flanks of the screws and is then propelled axially from both the ends towards the centre.

Horizontal external bearing

Roto's horizontal external bearing Twin Screw Pumps find its suitablility for handling fluid that shows different characteristics at different temperature.

These pumps are available in standard foot mounted & center-lined mounted configuration with or without steam jacketing arrangement. Guarantees reliable running and long life for all liquids whether it is neutral or aggressive.

Horizontal internal bearing

Roto's horizontal internal bearing Twin Screw pumps are available in standard foot mounted configuration with sump heating arrangement as an option.

These pumps are selected where the fluids are clean and have lubricating properties.

Vertical internal bearing

Roto's Vertical Twin Screw Pumps are available in both external & internal bearing configuration. Pumps with steam jackteing as an option is also available. The suction & discharge ports are in a line.


Mechanical seals are standard. Option for gland packing is also available. Pumps are fitted with relief valves suitable for 100% bypass. 



Material Options :

Casing                         : Cast Iron, Cast Steel, Fabricated Steel, Fabricated

                                     Stainless Steel.

Liner                            : Case Steel, Stainless Steel.

Screws                         : Alloy Steel, Stainless Steel, Hardened Steel.

Timing Gears                : Hardened Steel.

Other Exotic Material     : Duplex, Super Duplex.

Screw Surface Coating   : Hard Chrome Plating.


Features & Benefits :

Long and trouble-free service life Due to absence of metal to metal contact     between the pumping elements. Can even run dry for limited period of  time.

No axial thrust Dual flow of liquid in opposite direction balances axial thrust.


Higher volumetric efficiency Due to special double profile of screw flanks.


High cavitation free suction lift Due to low NPSH (R).


Self-priming and capable of handling entrapped air/vapour/gas Due to positive displacement action and being inherently self-priming.


Uniform metered flow Being a positive displacement pump, head developed is independent of speed and capacity is approximately proportional to speed.


Capable of handling wide variety of Fluids Lubricating/non-Lubricating as well as aggressive liquids can be handled due to choice of different designs and material of construction.


Safe to operate Has in-built relief valve designed to bypass upto 100% capacity.


Wider conformity to API 676, 2nd edition.