Pressure Testing
Radius Subterra delivers controlled pressure testing services that confirms fitness for service and provide clear assurance, regulatory compliance and confidence.
Independent verification of pipeline strength, tightness and compliance across gas, water, wastewater, energy and industrial pipeline systems.
Pressure testing is a critical verification step for new installations, diversions, repairs, rehabilitations and alterations. Radius Subterra delivers pressure testing on polyethylene (PE) and metallic pipelines across gas, water, wastewater, biogas, industrial and specialist networks, working in line with project specifications, network requirements and recognised industry practice. Our testing services provide verified integrity, clear compliance evidence and confidence that assets are safe to commission, operate or return to service.
Where programmes demand faster assurance, we deploy acoustic pressure testing (often referred to as advanced pressure testing). This approach uses acoustic measurement to account for temperature effects during the test, allowing stabilisation to be achieved more quickly and improving confidence in test interpretation. This reduces site time compared with conventional pneumatic tests, particularly where temperature variation would otherwise prolong the test window.
For higher test pressures and strength validation, hydrostatic (hydraulic) testing remains a widely accepted method across multiple industries, including gas transmission and other high-integrity systems, using a liquid test medium to minimise stored energy risk relative to compressible gas methods.
For higher test pressures and strength validation, hydrostatic (hydraulic) testing remains a widely accepted method across multiple industries, including gas transmission and other high-integrity systems, using a liquid test medium to minimise stored energy risk relative to compressible gas methods.
Where hydrostatic testing is not practicable due to operational constraints, system design, contamination risk or the nature of the asset, pneumatic testing may be specified. Because pneumatic testing stores significantly more energy, it requires tighter controls, exclusion zones and a robust, documented procedure aligned to the governing standard and project risk assessment.
Across all methods, our approach prioritises safe setup, controlled pressurisation, continuous monitoring and clear acceptance criteria. Each test is planned with consideration for venting, air management, instrumentation suitability and site constraints, and supported through structured reporting so clients have traceable evidence of test conditions, results and sign-off. This ensures assets are tested safely, efficiently and in full compliance with applicable standards.
Key Benefits
Efficient testing with reduced time on site
Access to multiple test methods, including acoustic pressure testing, enables the most suitable approach to be selected, reducing overall test duration and minimising programme disruption.
End-to-end quality assurance
Pressure testing completes Radius Subterra’s end-to-end delivery capability, ensuring installation, connection, verification and handover are managed as a single, coordinated process with clear responsibility and consistent quality control.
Assured compliance & asset integrity
Independent verification confirms pipeline strength and tightness criteria, providing documented assurance that assets are safe, compliant and ready for commissioning or return to service.
Pressure Testing technologies
Engineered pressure testing methods that verify pipeline integrity, ensure regulatory compliance and provide clear assurance before commissioning or return to service.
Acoustic pressure testing
Acoustic pressure testing is delivered by Radius Subterra as a specialist service designed to accelerate programmes, reduce cost and increase confidence compared with conventional pneumatic testing. By combining controlled air pressurisation with advanced acoustic measurement, our teams can accurately account for temperature change within the pipeline, removing one of the main causes of false failures and extended site time.
Using proven acoustic technology deployed by our trained engineers, we measure sound speed within the test section to determine average temperature change across the entire pipeline length. This data is used to correct pressure readings in real time, allowing genuine leaks to be distinguished from natural pressure variation caused by thermal effects or pipe creep. The result is faster, clearer pass/fail decisions and far fewer aborted or repeated tests.
For clients, the benefits include measurable programme and cost savings. Acoustic pressure testing can eliminate lengthy conditioning periods and can reduce test durations by up to 75% on live utility projects. Fewer re-tests mean lower labour and plant costs, reduced traffic management, and less disruption to surrounding assets. Radius Subterra provides full test management, compliant procedures and clear digital test records, supporting confident commissioning, regulatory assurance, and on-time project delivery across gas, water, and industrial pipeline networks.
Delivered in association with MTS Contracting.
Hydrostatic testing
Hydrostatic (hydraulic) testing is delivered by Radius Subterra as a controlled, standards-led service to verify pipeline strength and integrity after installation and before commissioning. The pipeline is filled with water, air is carefully removed, and pressure is applied using a water-fill system to a defined test pressure above normal operating conditions. Because water is effectively incompressible, hydrostatic testing provides a stable and reliable method of confirming that pipes, joints, and fittings are structurally sound and leak-tight prior to being placed into service.
Our engineers manage the full testing process, including isolation, filling strategy, controlled pressurisation, monitoring, and depressurisation, in accordance with recognised industry guidance and client specifications. Instrumentation is calibrated, results are recorded continuously, with outcomes clearly documented to provide auditable assurance of asset performance.
Hydrostatic testing is widely used on water and wastewater pipelines, rising mains and other high-consequence assets where long-term reliability and environmental protection are critical. The method is particularly effective at identifying leaks, joint defects or installation issues that could otherwise lead to failures after handover. In gas infrastructure projects, hydrostatic testing may be applied to specific components or assemblies during pre-commissioning strength verification, with final tightness testing carried out pneumatically in line with gas industry requirements.
By getting the test right first time, Radius Subterra helps reduce programme risk, repeat testing, and unnecessary site revisits. This reduces the total time the pipeline, highway, or work area needs to be taken out of normal use, minimising disruption and delivering clear compliance records that confirm the asset is fit for service.
Pneumatic testing
Pneumatic testing is delivered by Radius Subterra as a controlled pressure testing service used to verify pipeline tightness and integrity after installation and before commissioning, particularly where water-fill is impractical or not permitted. The test section is pressurised with air or inert gas to a defined pressure and monitored to confirm that pressure is maintained within allowable limits, demonstrating that joints, fittings, and connections are leak-tight.
Our teams carefully manage pressurisation rates, stabilisation periods, and monitoring in line with recognised industry guidance and client specifications. Due to the compressible nature of air, pneumatic testing requires disciplined control and experienced execution. Radius Subterra applies calibrated instrumentation and continuous data logging to ensure clear, reliable results and auditable records for client assurance and regulatory compliance.
Pneumatic testing is commonly used on gas pipelines, service connections, and sections where water introduction could create contamination, drainage, or disposal challenges. It is also applied where rapid testing and de-pressurisation are required to maintain programme progress. By applying best practice around temperature stabilisation, pipe material behaviour, and pressure decay assessment, our approach reduces the risk of false failures and unnecessary re-tests.
Delivered correctly, pneumatic testing supports efficient commissioning while maintaining high safety standards. Radius Subterra’s experience allows testing activities to be completed first time, lowering site disruption, reducing repeat visits and reducing the total time the pipeline, highway, or work area needs to be taken out of normal use. This ensures a safe, compliant, and efficient route to asset commissioning across all pipeline sectors.
Our other solutions
Explore other Radius Subterra solutions designed to enhance safety, efficiency and long‑term performance.
Under Pressure Connections
Pre-Insulated Pipework
Pipework Installation & Mainlaying
Pipe Cutting
Manufacture & Fabrication
Engineering and Project Management
Pipe Lining
Pipeline Repair & Maintenance
Flowstopping
Case Studies
Discover the prowess of Radius Subterra through our latest case studies.
Witness how we excel in tackling intricate pipeline challenges with innovative solutions and state-of-the-art technology. Stay tuned for more videos showcasing our commitment to engineering excellence.
Faced with severe leaks in a critical 1500mm trunk main, Radius Subterra provided an innovative pipeline rehabilitation solution using their close-fit PE liner system. This approach restored the pipeline’s integrity
Discover how Radius Subterra’s precision engineering revitalises a historic London waterway with cutting-edge pipeline solutions, installing a bespoke branch saddle onto a live water main in Finsbury Park. This job
Radius Subterra partnered with Anglian Water to solve leak issues in a hard-to-reach 10” water pipeline in East Anglia. Using their innovative Rolldown & Slipline method, Subterra maximised pipe bore
In February an accidental incident occurred that resulted in a 10” gas main being damaged, and a hole being drilled into the main. The incident was near to the main
Case Studies
Discover how Radius Subterra delivers safe, innovative and technically assured solutions across the UK’s most challenging pipeline environments.
Faced with severe leaks in a critical 1500mm trunk main, Radius Subterra provided an innovative pipeline rehabilitation solution using their close-fit PE liner system. This approach restored the pipeline’s integrity
Discover how Radius Subterra’s precision engineering revitalises a historic London waterway with cutting-edge pipeline solutions, installing a bespoke branch saddle onto a live water main in Finsbury Park. This job
Radius Subterra partnered with Anglian Water to solve leak issues in a hard-to-reach 10” water pipeline in East Anglia. Using their innovative Rolldown & Slipline method, Subterra maximised pipe bore
What our client’s say about us
Why choose Radius Subterra?
Trusted expertise, engineered solutions and a service approach shaped around your challenges.
For decades we’ve supported utility networks in the UK and beyond with safe, reliable and efficient pipeline services. Our teams combine technical knowledge, industry-leading equipment and a problem-solving mindset to deliver high-quality outcomes with minimal disruption. Whether planned works or complex operational challenges, we provide proven capability and dependable support.
Decades of expertise
With deep roots across the wider Radius Group and extensive experience in live gas, water, biogas and pipeline rehabilitation operations, our teams bring exceptional hands-on knowledge to every project. We understand the pressures faced by network operators and contractors and deliver work that is safe, compliant and technically robust from start to finish.
Committed to quality and safety
Safety underpins every service we deliver. Our work follows industry standards, rigorous internal procedures and environmental best practice. From accredited techniques to specialist equipment, we ensure consistent quality while reducing risk, waste and unnecessary disruption across gas, water and biogas networks.
Minimising disruption
Our specialist techniques, including under-pressure connections, flowstopping and trenchless rehabilitation, allow essential works to continue while maintaining customer service, protecting highways and minimising community impact. Reduced excavation and streamlined operations, support faster reinstatement and lower overall disruption.
Innovation and customisation
From bespoke branch saddles to tailored fittings for non-standard assets, innovation is central to our approach. We engineer solutions to suit each site, material and operating condition, enabling safer, faster and more cost-effective outcomes across complex project environments.
Safety and sustainability
We champion safe working and long-term sustainability. Our methods reduce carbon, excavation material, traffic disruption and reinstatement, while modern equipment and ongoing training create a safer environment for teams and the public. Every project is designed and delivered with environmental responsibility and operational resilience in mind.
Contact us
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