Sewage Treatment

Northey has been recognised for more than 40 years as the market leader in the manufacture and supply of sludge mixing compressors for the water industry. Our proven ‘Hook & Claw’ principle has been adopted as the preferred technology by many of the leading water authorities, due to its many operational advantages. In the application of sludge mixing, the Northey ‘Hook & Claw’ re-circulates and compresses biogas without any oil contamination or contact between rotating parts. This ensures there is no possibility of oil carry over into the process as well as other problems associated with oil in the system – leakage through moisture drains and the blocking of ancillaries such as flame arresters. Many sites have reported excellent life costs and minimal maintenance, which has become more critical with the reduction in manned sites. Northey also offers rotary vane compressors for gas mixing where the flow and pressures mean Hook & Claw is not possible.

Northey has also supplied many air blowers for sewage treatment, especially on small population plant where compact size, noise, efficiency, capital and running costs are all of equal importance. Developments in the area of variable speed have shown Northey compressors to be extremely reliable and capable of greater turndown ranges than many of its rivals.



Biogas is one of the most difficult gasses to handle due to its moisture content and corrosive nature. Northey compressors and blowers are proven to work successfully on the most demanding applications such as, biogas mixing systems and gas boosting for power generation. All of our packages and ancillary items are designed to withstand the long term effects of the gas, both internally and externally. As a result, many of our packages remain in operation well beyond the anticipated life of the plant.


Waste and Clean Water

There are many applications for low pressure air in the waste water market, which range from simple aeration to air scour and filter backwashing. Most requirements are suited to our Side Channel and Roots ranges as they are oil-free and offer many operational advantages over other makes and designs on the market. Most noticeable, is the saving on power and cost, as well as the ability to custom build the blowers to WIMES as required. As a specialist supplier in this market, we have also developed our blower range for frequency control, giving optimum operating efficiency. In addition, customers can specify their preferred motor manufacturer, which, unlike many other blower designs, can often be fitted in a direct coupled arrangement, eliminating the need for a belt driven system.


Power Generation

The effective handling of gas is critical in the area of power generation. Not only does the compressor/booster need to generate the required pressure and flow for optimum system operation, but it needs to work with the highest reliability. From our extensive range of booster sets and compressors, we can select to meet the exact needs of the client.

Northey are a Framework supplier for Thames Water, South West Water and Wessex Water. In addition to the Northey Hook and Claw product we can offer a range of roots blowers and screw compressors from well known manufacturers, side channel blowers and boosters, gas bag and total process design. We also offer comprehensive service packages for all of the above, covering all levels of service from emergency one off visits to complete contracts.

We can offer

  • Gas & Air Compressors / Boosters – Hook & Claw, Sliding Vane, Liquid Ring, Roots/Rotary Lobe, Side Channel and Fans
  • Air Blowers – Centrifugal, Turbo Blowers, Roots/Rotary Lobe, Hook & Claw, Side Channel and Fans
  • Spares – We are able to supply spares for all types of blowers and hold many parts in stock
  • Test Facilities – We have extensive test facilities for Northey machines and facilities for other models
  • Planned Preventative Maintenance – Site Surveys and Service Contracts

We can carry out site surveys with a view to improving efficiency by identifying existing or potential problems with compressors and associated process equipment and suggesting solutions to these problems

As an independent Gas Handling Specialist, Northey can offer unbiased advice on the sizing and selection of roots type, side channel blowers and turbo blowers across the industry. We can design packages to meet your needs, and work closely with you to supply and commission to your requirements.

Northey have worked closely with many Utility Companies to design and build new digester schemes. Please get in touch for more details.

We are very pleased to be able to announce our partnership with VSO in France, producing a range of high quality gas bags at a competitive price. We can now quote all aspects of gas storage, from a simple bag to a complete, commissioned scheme.