About Allison Engineering
Established in 1979. Trusted across the UK & Ireland. Built on knowledge, service and long-term relationships.
Over 45 Years in Operation
1000's of UK Installations
Supporting 100's of UK Sites
We have been helping customers solve process control, gas analysis, flow measurement and safety challenges since 1979.
Over the decades, we have built our reputation by combining trusted products with practical engineering support, honest advice and long-term customer relationships.
Today, we are proud to remain a family-owned business led by Jeff and Simon Harwood, continuing the work their father started, and growing Allison Engineering for the future. As the markets we serve continue to evolve, we are investing in how we present ourselves, how we share our expertise and how we make it easier for new customers to discover what we do.
Our Story
Allison Engineering was founded by the Harwood family in 1979 with our first office in Billericay, Essex. When our founder retired, ownership passed to Jeff and Simon Harwood who remain the owners of the business.
In the early years, the business focused on gas detection for the Oil & Gas industry, working with General Monitors as our original principal. As the needs of our customers evolved, so did we. Over time, we expanded our portfolio to include flow measurement, level measurement and safety-related products, helping customers across a much wider range of industrial and process applications.
That continuity matters to us. It means the values the business was built on are still present in the way we work today: putting customers first, being honest and transparent, continuing to learn, and always looking for ways to add value beyond simply supplying equipment.
We have grown steadily over the years, and that growth has come from doing the job properly, building trust, and supporting customers long after the initial sale.
What We Do
We support customers with specialist process control solutions, flow and level measurement, gas analysis, safety and industrial support services. Over the years, we have developed specialist expertise in areas including:
- Flow & level measurement
- Biogas analysis
- Gas detection and safety systems
- Process control solutions
- Biological desulphurisation
- PSA and VSA oxygen generation technologies
- Industrial safety products
- First fix, commissioning, servicing and maintenance support
Our role is not just to supply products. We help customers choose the right solution for the application, support installation and commissioning, and continue to provide service and maintenance support once systems are in the field. That practical, hands-on approach is a big part of what our customers value.
Our Areas of Specialism
Biogas & Renewable Energy
We have developed strong expertise in the biogas market, where measurement accuracy, reliability and service support are essential.
Our work in this sector includes biogas analysis, flow measurement, oxygen generation systems, and biological desulphurisation solutions. We are trusted to support customers across anaerobic digestion, gas upgrading and related renewable energy applications, and we continue to deepen our knowledge as the market evolves.
Flow & Level Measurement
We supply flow and level measurement solutions into demanding industrial environments where accuracy, repeatability and long-term reliability matter.
Our work includes thermal dispersion flow measurement technologies used across industries ranging from oil & gas to wastewater treatment and other process sectors - using product ranges that have proven, dependable repeatability and reduced maintenance requirements.
Gas Analysis & Monitoring
We support customers with biogas analysis and monitoring solutions covering gases such as CH4, CO2, O2, H2S, CO and H2, as well as providing installations, commissioning and servicing support.
Gas analysis and monitoring is an area that requires accuracy and reliability at all times. And where technical support and knowledge matters just as much as the instruments themselves, our customers continue to rely on us through trusted relationships.
Site Support & Maintenance Services
We support customers beyond product supply with a practical range of site support and maintenance services, including consultations, first fix support, commissioning, servicing and planned maintenance.
Our engineers work across the UK & Ireland, helping customers install, maintain and optimise systems in real operating environments. That hands-on support is an important part of how we work and helps customers keep critical equipment performing reliably over time.
Need information or advice?
Speak with our friendly, expert team to discuss your requirements and find out how we can help you.
Our Values
The way we work is shaped by a set of straightforward values that have guided the business over many years.
Customer-First
Without customers, we do not have a business. We put customers first by listening carefully, responding honestly and supporting them properly.
Honest & Transparent
We believe in being clear and straightforward with our customers and suppliers. Trust is built through honesty, and that matters to us.
Expertise & Learning
We have deep knowledge in our specialist areas, particularly in biogas and process applications, but we never stop learning to evolve with the times.
Support & Value
We add value through application knowledge, engineering support, service capability and commitment to helping customers solve real problems.
Our Areas of Specialism
Biogas
Specialist process control solutions for anaerobic digestion and biogas upgrading, including gas analysis, flow measurement and desulphurisation systems. Supporting operators to improve efficiency, gas quality and long-term plant performance.
Wastewater & Water Treatment
Measurement and control solutions for wastewater treatment processes, including aeration air flow and biogas systems. Helping operators improve efficiency, reduce energy use and maintain consistent treatment performance.
Oil & Gas
Proven solutions for flow, gas measurement and process control across upstream and downstream operations. Supporting applications such as flare gas, chemical injection and analyser systems in demanding industrial environments.
Hydrogen
Flow measurement and process control solutions supporting hydrogen production, storage and use. Designed for accuracy, safety and reliability in applications including hydrogen flow monitoring and emerging energy systems.
Chemical
Reliable measurement and control solutions for challenging chemical processes, including low flow, high pressure and corrosive applications. Designed to support safety, efficiency and consistent process performance across a wide range of duties.
Pharmaceutical
High accuracy monitoring solutions for clean utilities and process gases in pharmaceutical environments. Supporting process consistency, compliance and reliable operation across critical manufacturing and analytical systems.
Food & Beverage
Process monitoring solutions for compressed air, gas and utility systems used in food and beverage production. Supporting efficiency, product quality and compliance through accurate and reliable measurement technologies.
Trusted Products, Trusted Partnerships
Over the years, we have built strong relationships with specialist manufacturers and technology partners whose products are trusted around the world.
In biogas and related applications, we act as exclusive distributors in the UK for leading manufacturers of biogas equipment, allowing us to provide customers with proven technologies backed by local support and long-term service capability.
These relationships matter because they allow us to combine the strength of established global manufacturers with the responsiveness and hands-on support of a UK engineering business.
For our customers, that means access to proven products, supported by people who understand the application and can help in the real world.
Experience You Can Measure
We believe experience should be visible in the work itself. Over the years, we have built a strong installed base across multiple sectors and application types.
In anaerobic digestion, there are 180+ UK locations using Awite biogas analysers. In wastewater, we have framework agreements with multiple water authorities for aeration air and biogas flow meters, with over 1000 instruments supplied.
We also support applications across power, including multi-point gas flow meters for combustion air, primary air, secondary air, BOFA and over-fire air, as well as compressed air monitoring for energy usage across industrial sites.
This comes from years of trusted supply, successful installations, repeat business and customers who rely on us to keep critical systems operating.
Delivering Innovation
Advances in technology needn't come with uncertainty. Our focus is to deliver proven, process innovation to your advantage. We are at your service.
Why Trust Allison Engineering
We are committed to delivering the highest standards across the specialist areas we support, combining proven products with practical engineering knowledge and dependable service.
Need Help with your Process Control Applications?
Allison Engineering can help you identify the right solutions for your application, process conditions and site requirements.