Main benefits
  • Modular hydraulics for high efficiency in a wide range of operating conditions as required for gas-fired combined-cycle power plants
  • Optimized design for thermal conditions as applicable in gas-fired combined-cycle power plants
  • Large branch sizes for optimized inlet flow, low noise level and higher allowable forces and moments
  • Unaffected by rapid temperature variations and therefore highly suitable for gas-fired combined-cycle power plants where frequent start-stop operation is specified
  • Easy access to the seal cooling chambers for cleaning
  • Stiff shaft design for critical speeds above the maximum operating speed
Main applications

The MC pump is primarily designed for power applications, such as: auxiliary boiler feed services; Nitrogen Oxides (NOx) abatement and fuel injection in combined-cycle power plants; boiler feed for biomass fired and industrial power plant; and steam generator feed in concentrated solar power plants. The design is ideal for:

  • Main and auxiliary boiler feedwater pump duties up to 180°C
  • Nitrogen Oxides (NOx) abatement and fuel injection in gas-fired combined-cycle power plants
  • Condensate extraction pumps in power stations and industrial plants
  • Auxiliary services within gas-fired combined-cycle and industrial power plants
  • Feedwater pump in desalination by reverse osmosis
  • High pressure water in general industry
  • Feedwater pump for gas-fired combined-cycle power plants
  • Feedwater pump for concentrated solar power plants
  • Boiler feedwater pump for biomass and industry power plants
Features and benefits
Cutaway of MC high pressure stage casing pump
1. Casing support

 Foot or shaft centerline mounted for large sizes and high temperatures

2. Branches
  • Large suction branches optimize inlet flow
  • Reduce noise levels through low branch velocities
  • Allow higher forces and moments
3. Impellers 
  • Several hydraulic sets per pump size guarantee high efficiencies and low operating costs over a wide operating range
  • Low net positive suction head required (NPSHR) first stage; double suction first stage can be provided for selected sizes
4. Shaft 

Stiff design resulting in higher critical speed than running speed and small shaft deflection. Areas subject to wear are protected

5. Intermediate take-off 

Up to two bleed-off nozzle are possible

6. Hydraulic thrust balancing system 

Axial thrust can be balanced by balance drum with thrust bearing or by balance disc without thrust bearing

7. O-rings 

Casing sealing by confined O-rings, therefore unaffected by rapid temperature variations and high pressures  

8. Multiple bearing types 

Antifriction bearings for low cost and hydrodynamic bearings for higher energy services

Operating data
50 Hz 60 Hz
Discharge sizes up to 350 mm up to 14 in.
Capacities up to 1,860 m3/h up to 9,720 US gpm
Heads up to 1,750 m up to 5,500 ft.
Pressures up to 180 bar up to 2,610 psi
Temperatures up to 180°C up to 356°F
Performance range
MC performance range 50 Hz
Performance range 50 Hz
MC performance range 60 Hz
Performance range 60 Hz
Pump part Material
Suction, stage and discharge casing
Carbon steel, chrome steel, duplex steel
Impellers and diffusers Carbon steel, chrome steel, duplex steel
Shaft Chrome steel, duplex steel
Balancing system Chrome steel, duplex steel
  • Boiler feed pump (BFP) for biomass waste
    Boiler feed pumps for biomass firing power plants applications are typically small/medium ring section type. Axially split multistage pumps are also available when required. The pump size and the design pressure will depend very much of type and the output of the power plant.

  • Brine re-injection pump
    The brine re-injection pump re-injects the low enthalpy reject brine back to the geothermal field to renew the available resources.

  • Feed water pump (FWP) for gas-fired
    Feed water pumps (FWP) pump the feed water from the de-aerator through the HP heaters to the heat recovery steam generator. The major characteristic of the FWP is their high differential head. In all sizes of gas-fired combined-cycle power plants, the FWP are horizontal ring section type; occasionally, they could also be barrel or axially split type.

  • Feed water pumps for solar power generation
    Feed water pumps (FWP) pump feed water from the de-aerator through the HP heaters to the solar steam generator. The major characteristic of FWP is their high differential head. The FWP are usually horizontal ring section type, but depending on customer requirements, they can also be barrel or axially split type.

  • Power plants
    Sulzer’s extensive product portfolio to maximize the performance and reliability of your solid organic fuel biomass power plant, solid industrial or municipal waste fuel biomass power plant, and liquid or gaseous organic fuel biomass power plant processes.

  • RO-island HPP
    This is the heart of the SWRO Desalination process, where the desalination effect takes place. The Treated sea water is fed by means of the High Pressure pumps into the RO membranes, obtaining permeate or product water and high pressure brine rejection, whose high pressure energy is recovered by selected Energy Recovery Device.

  • Water transportation
    Water transport pumps are pumping large volumes of water over mostly long distances and high geodetic heights to geographical areas or industries where it is required for different purposes. We offer various configurations according to your needs.
Optional designs
MC balance drum
Balance drum
Balance drum

The balance drum device carries the major proportion of the hydraulic thrust. The drum diameters are chosen to minimize the thrust at normal operating point. The residual and additional thrust loads occurring above/below the normal operating point are carried by the thrust bearing, typically a taper roller bearing.

The balance drum is suitable for:

  • Long life under extreme operating conditions
  • Frequent stop-start applications thanks to nearly wear-free device  
MC & MD high pressure pump balance disc
Balance disc
Balance disc

With the balance disc, the axial force is completely compensated, therefore no axial thrust bearing is required.

The disc designs are optimized for each hydraulic and size.

For operation with frequent start and stops, the installation of a lift-off device is available (either mechanical or magnetic).


NDE bearing arrangement with balance disc and mechanical lift-off device
NDE bearing arrangement with balance disc and mechanical lift-off device
Mechanical or magnetic (PERMAVORTM) lift-off device


  • Prevents touching and wearing of the disc/counter disc during operation at low speed, such as start up and shut down
  • Self-controlling passive system
  • Reduces load on balance disc under normal operation
  • Integrated into the radial bearing housing; no additional power consuming bearings required
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