Why Use Hampro Variable Flow Pumps?

These pumps offer variable flows via adjustable stroke control. The technology of the Hampro variable stroke pump eliminates the need for a VSD, thus offering a considerable cost saving in both hardware and site installation costs.

The variable stroke pumps are the latest chapter in the progress of Hammelmann – a manufacturer of precision-engineered, high quality pumps known worldwide for their reliability. We have worked together with Hammelmann, combining their pumps and Calder packaging experience, to deliver process packages to the energy sector for over 30 years.

The variable stroke range allows precise flow rate adjustments of 0-100%. The stroke adjustment can be made automatically or manually, and while the pump is on or off load. The pump range offers flow rates of up to 203 litres per minute and pressures up to 3,500 bar. These versatile units are frequently used where the pump skid is installed in an ATEX Zone 1 hazardous area.



Hampro Variable Stroke Features:

  • Variable Stroke/Variable Flow Zero to 100%.
  • API 674 & API 675 Compliance.
  • Zero Emissions.
  • Efficiency: >95%VE & 95%ME.
  • Pressures up to 3,500 bar (50,750 psi).
  • MTBF: 12,000 hrs ++.
  • ATEX Zone I & II Compliant.
  • Material Options; 316SS, Duplex, and Super Duplex.
  • Smooth, adjustment of the flow rate.
  • Compact, low weight design with small footprint.
  • Highly energy efficient. Flow rate adjustment without energy loss also under partial load.

A trailer-mounted high pressure water jetting pump in the yard at our Worcester factory

What are the Benefits of using the Hampro Pump

Calder Hampro variable stroke pump packages offer signifcant benefits, particularly at higher volumes and pressures ≥200 bar:

  • Significantly smaller footprint.
  • Significant package weight savings.
  • Energy efficient pump, converting 93% to 98% of the shaft power to hydraulic energy.
  • High reliability delivering extended Mean-Time-Between-Failures (MTBF).
  • Capacity to handle dirtier fluids at higher pressures.
  • Reduced levels of vibration/pulsation.
  • Lower noise levels.
  • Zero risk of high pressure process fluid leakage to atmosphere with zero emissions option.
  • Reliable control and containment of low pressure leakage.
  • Eliminates the risk of contaminating hydraulic fluid.
  • Pressurised power end oil lubrication & filtration system.


4 Examples of Our Experience Packaging Hammelmann Variable Stroke Pumps

A compact methanol injection pump skid utilising the Hammelmann Hampro pump technology.

A very compact ATEX-compliant methanol injection package designed to strict footprint criteria.
This challenging design is for a platform with significantly limited deck space.

A MEG injection pump skid utilising Hammelmann Hampro Pumps.

A chemical injection unit for the Johan Sverdrup field. This pump skid features twin Hampro variable stroke pumps and was designed to be compact with a minimal unit footprint.

As with all our process pump packages the unit was designed, built, and tested here at our factory in Worcester, UK.

Methanol injection pump skid for offshore hazardous area operations.

This MEG Injection Package is used for the hydrate inhibition of wells prior to start-up and shut down. The skid is designed for single point lifting and to withstand the specified external, environmental and accidental loads. The skid is supplied with a deck-mounted environmental enclosure to protect the equipment from harsh weather and to achieve the relevant platform noise level requirements.

Compact, twin pump chemical injection package with Hammelmann Hampro variable stroke pumps.

An ATEX Zone 1-compliant pump skid for TEG Injection. This pump skid package will operate on a semi-submersible platform.

The base frame was constructed using 316 stainless steel, the tubing and valves are Duplex, and the instrument tubing and fittings are manufactured in 6mo.


Where to see Hammelmann Hampro Variable Stroke Pumps

We will once again be at this year’s ONS exhibition in Stavanger, Norway – 24-27 August 2026. On our stand will be a working demonstration unit that features the Hampro 20V pump. If you can’t wait until August, then please get in touch with us.


Talk with Us

Whatever your application, we are here to help. Please call us on +44 1905 751790 or email sales@calder.co.uk to discuss how we can help you with your next process project.


More Information on our Process Pump Units

Boosting, Circulation and Cooling Pumps
Chemical Injection Packages
CO2 Injection Pumps
Geothermal Energy Recovery Pump Systems
MEG, TEG, and Methanol Injection Pumps
Power-to-X Pump Systems (P2X)
Produced Water Injection Pumps




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