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Screw Centrifugal Impeller

Hidrostal is the inventor of the screw centrifugal impeller and is totally dedicated to its development and improvement. For more than 30 years a continuous research and development programme has given Hidrostal a technology advantage in handling difficult materials.  This has lead to a family of pumps being developed with variations of the screw centrifugal impeller to solve specific pumping problems.

Key features of Screw Centrifugal Impeller are:

  • Energy savings of up to 50% compared with conventional centrifugal pumps.  Same high efficiency maintained in Hidrostal’s immersible, submersible and end suction pumps
  • Non-clog impeller suitable for pumping high consistency media and large diameter solids beyond the capacity of centrifugal and recessed impeller pumps
  • Easy adjustment of impeller clearance permits continuity of original high-efficiency performance
  • Optional renewable liner to reduce maintenance costs when pumping abrasive media.
  • Low N.P.S.H characteristics
  • Available in choice of materials

Materials of Construction

Code 1   Code 4
 [Limited models only]
Casing: Cast Iron Casing: Cast Iron
Impeller: Nodular Iron Impeller: 25% Chrome Iron
Liner: Cast Iron Liner: 25% Chrome Iron
Code 2   Code 5  
Casing: Cast Iron Casing: St. St. 316
Impeller: Nodular Iron Impeller: St. St. 316
Liner: 25% Chrome Iron Liner: St. St. 316
Code 3   Code 6  
Casing: Cast Iron Casing: CD4-MCU
Impeller: Steel [16% Cr+Mo] Impeller: CD4-MCU
Liner: 25% Chrome Iron Liner: CD4-MCU

CD4-MCU = Duplex Stainless Steel [alternative Steel DIN 1.4460]
Optional Material:  Ni-Resist ASTM 436 Type 2

Material Codes 2 to 4 have hard high chrome iron liners which are externally adjustable on site to maintain the correct impeller clearance and pump efficiency over many years of operation, except for small submersibles where the liner is fixed. .

NOTE:   The ranges of materials shown are Hidrostal’s standard combinations. They can be mixed and matched to suit the application.  For applications presenting unforeseen problems, alternative materials can be used as most parts are fully interchangeable irrespective of the materials

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