Manufacture & Fabrication

Radius Subterra delivers specialist manufacture and fabrication of bespoke pipeline fittings and assemblies engineered to suit specific asset, operational and installation requirements.

Working across gas, water and industrial networks, components are designed and built to suit host pipe material, diameter, wall thickness and operating conditions, supporting both planned works and live network operations.

Our bespoke PE fabrication capability enables complex polyethylene pipe assemblies to be produced off-site using controlled butt fusion and electrofusion processes. Fabrications can incorporate mitred butt-fused joints, couplers, reducers, tapping tees, and low-profile branch saddles within a single build, creating ready-to-install configurations tailored to the connection or modification. 

Designer and bespoke-sized and branch saddles can also be manufactured for non-standard pipe sizes or constrained locations. In many cases, these solutions provide a practical alternative to more invasive intervention methods, avoiding decommissioning, large excavations, or extensive reinstatement.

For metallic pipelines, Radius Subterra manufactures and supplies large-diameter fittings including flange adapters, under-pressure tees, end caps, and grouted tees and sleeves.

  • Flange adapters are produced to suit the measured outside diameter of the host pipe, supported by on-site callipering to ensure accurate fit-up and reliable sealing. 
  • Under-pressure tees provide a sealed interface for live drilling and branch installation while the main remains operational.
  • End caps are used to safely terminate pipelines during maintenance, testing, staged works, or decommissioning activities.
  • Grouted tees and sleeves provide structural, pressure-retaining solutions without the need for welding.

Radius Subterra provides a complete end-to-end service including consultation, CAD design, manufacture, installation, and full reporting. Managing design, fabrication, and delivery under a single scope ensures dimensional accuracy, controlled installation, and compliance with relevant industry standards.

This integrated approach reduces interface risk, improves programme efficiency and provides asset owners with assurance that each component has been engineered and installed in line with operational requirements and long-term performance expectations.

Key Benefits

Bespoke sizing for accurate fit-up 

Components are manufactured to match the actual pipe diameter, material and wall thickness, ensuring accurate fit, reliable sealing, and reduced need for on-site modification or adjustments. 

Engineered solutions for site constraints 

Fabrications are designed to suit restricted access, congested excavations, and complex layouts, providing practical connection solutions where standard fittings or conventional methods cannot be installed easily. 

End-to-end delivery 

A single coordinated service, from consultation and CAD design to manufacture, installation and reporting, ensures quality control, consistency, and efficient progression from planning to completion. 

Resources

Flowstopping benefits brochure – (PDF)

Manufacture & Fabrication technologies

Engineered manufacture and fabrication technologies delivering bespoke pipeline fittings and assemblies that support connections, repairs and live network operations across all asset types.

Bespoke polyethylene (PE) fabrications
Bespoke polyethylene (PE) fabrications

Bespoke PE fabrications are delivered by Radius Subterra for use across all industries, providing pre-engineered polyethylene pipe assemblies tailored to specific site and installation requirements. Fabrications can be produced across a range of pipe diameters, SDRs, and PE material grades, enabling complex pipework arrangements to be manufactured off-site and installed as a single, integrated solution. 

Assemblies can incorporate butt fusion and electrofusion joints, including mitred butt-fusion angles to achieve accurate changes in direction or alignment. Electrofusion components such as couplers, tapping tees, and branch saddles can be integrated into the fabrication, reducing on-site jointing and simplifying installation. 

A key application of Radius Subterra’s bespoke PE fabrications is the integration of low-profile branch saddles into purpose-designed pipe configurations. Traditional tee connections can be physically large and restrictive, particularly in congested excavations or chambers. Radius Subterra’s low-profile branch saddles provide a significantly reduced physical footprint, delivering meaningful space savings and lowering excavation and reinstatement costs.

Bespoke PE fabrications are also used for the manufacture of gas manifold systems and meter outlet pipework, where compact layouts, accurate alignment and controlled assembly are essential. Multiple fabrication elements, including mitred sections, branch connections, and tapping tees, can be combined into a single build to produce a compact, ready-to-install assembly. 

Radius Subterra also provides CAD drawings and full fabrication reporting, including dimensional drawings for approval and comprehensive build records. By combining design, fabrication, and documentation, we deliver controlled, space-efficient PE fabrications that support reliable installation and long-term asset performance.

Bespoke-sized branch saddles

Radius Subterra offers an in-house bespoke branch saddle service, delivering engineered branch saddle solutions for all sizes of polyethylene (PE) pipe across all industries. Where standard fittings are unsuitable due to pipe diameter, SDR, geometry, or site constraints, bespoke and designer branch saddles are developed to meet specific operational and installation requirements. 

Using a designer branch saddle can deliver significant programme and cost savings. In many cases, the only alternative solutions would be to decommission the main or undertake a flowstopping and cut-out operation. Both approaches introduce greater disruption, either through supply interruption or by requiring larger excavations, longer site durations, and more complex reinstatement. A bespoke branch saddle can avoid or significantly reduce these impacts by enabling a controlled branch connection without full main isolation or extensive excavation. 

Designer branch saddles are engineered around the host pipe and connection requirement, allowing installation in constrained locations and on non-standard pipe sizes where off-the-shelf products cannot be used. Designs are produced to meet relevant EN and GIS requirements, providing assurance that mechanical performance and joint integrity align with industry standards. 

Radius Subterra provides an end-to-end service, including technical consultation, design development, manufacture, installation, and full reporting. Each bespoke saddle is supported by CAD design, manufacturing records, and installation documentation to support compliance and assurance. Post-installation, we provide ongoing technical support to ensure long-term asset performance assurance and operational reliability.

Flange adapters

Flange adapters up to 900 mm (48″) are manufactured and supplied by Radius Subterra to create accurate, secure connections between large-diameter pipelines and flanged valves, fittings, or pipework. They are used routinely on everyday pipeline connections and are equally effective on older or non-standard mains where achieving a reliable fit depends on accurate dimensional control. 

Adapters are manufactured to suit the actual outside diameter of the pipe, ensuring correct compression, alignment, and sealing performance. This is particularly important on large-diameter assets where nominal sizes, coatings, or manufacturing tolerances can vary. 

To support accurate manufacture, Radius Subterra offers an on-site callipering service to confirm the pipe outside diameter prior to fabrication. This ensures each flange adapter is produced specifically for the measured host pipe dimension, reducing installation risk and avoiding forced fit or on-site modification. 

Large-diameter flange adapters are commonly used during network modifications, valve installations, flowstopping activities, and asset replacement works where a flanged interface is required. Accurate dimensional matching ensures correct bolt-up, even gasket compression and a secure, leak-tight connection. 

Radius Subterra provides a fully integrated service, covering site measurement, bespoke manufacture, installation, and full reporting. Managing measurement, fabrication and installation under a single scope ensures controlled execution, reliable sealing performance and confidence that flanged connections are delivered safely and in line with industry expectations.

Under-pressure tees

Under-pressure tees (UPTs) up to 900 mm (48″) are manufactured and supplied by Radius Subterra to enable controlled connections to live pipelines without supply interruption. These fittings are engineered for under-pressure (hot tapping) operations, providing a stable, sealed interface that allows drilling and branch connections while the main remains operational. 

Each UPT is designed to suit the host pipe material, diameter, wall thickness, and operating conditions. The design focuses on maintaining sealing integrity throughout the drilling process and managing loads introduced during live drilling and connection works, ensuring the connection remains secure during installation and for the life of the asset. 

Manufacturing UPTs for large-diameter pipelines requires accurate dimensional control and a detailed understanding of live-network behaviour. Radius Subterra manufactures under-pressure tees to suit the actual outside diameter of the host pipe, which is particularly important on large or legacy mains where nominal sizes may not reflect true dimensions. This supports reliable fit-up, consistent sealing and predictable installation outcomes. 

Under-pressure tees are widely used for live network modifications, new connections, asset installations, and other interventions on operational mains. They are also key components for flowstopping activities, providing the access point required to install isolation equipment while the main remains live. UPT installations reduce disruption, limit excavation scope and shorten overall programme duration. 

Radius Subterra provides a fully integrated service, covering technical consultation, design, manufacture, installation, under-pressure drilling and full reporting. Managing the fitting and live-network operation under a single scope ensures safe, controlled execution and reduces interface risk across all project stages.

End caps

Radius Subterra manufacture and supply end caps up to 900 mm (48″) to deliver a secure means of terminating large-diameter pipelines during planned works. These fittings are used where a pipe end must be safely sealed to allow maintenance, modification, testing, or staged construction activities to proceed in a controlled manner. 

End caps are designed to suit the host pipe material, diameter, wall thickness, and operating conditions. They provide a robust, pressure-rated closure capable of withstanding internal loads and maintaining sealing integrity for the duration of the works. Designs can be configured to suit a range of connection methods and site constraints, supporting controlled installation on large-diameter assets. 

Manufacturing large-diameter end caps requires accurate dimensional control to achieve correct fit and dependable sealing. Radius Subterra supplies end caps manufactured to suit the actual outside diameter of the pipe, which is particularly important on large or legacy assets where nominal sizes may not reflect expected dimensions. This approach supports predictable installation and reduces the risk of leakage or forced fit on site. 

End caps are commonly used to enable pressure testing, isolation for maintenance or repair, and the decommissioning of sections of main, where pipelines must be safely sealed and left out of service. They are also used in conjunction with flowstopping operations, allowing isolated sections to be securely capped once cut. 

Radius Subterra provides a fully integrated service, covering design support, manufacture, installation, and full reporting. Managing supply and installation under one coordinated scope ensures safe execution, reduced interface risk and confidence that large-diameter terminations meet industry and asset owner requirements.

Grouted tees and sleeves

Grouted tees and grouted sleeves are manufactured and supplied by Radius Subterra for use on metallic pipelines where a structural, sealed interface is required without welding to the parent main. These fittings are installed externally around the pipe, with the annular space filled with a high-strength grout system to create a secure mechanical bond and pressure-retaining seal. 

Grouted tees create a connection point on a live main for under-pressure drilling and branch installation, while grouted sleeves provide reinforcement or repair to damaged or deteriorated pipe sections. Both solutions are widely used where maintaining supply is essential and hot work is not practical or permitted. 

Each fitting is manufactured to suit the host pipe diameter, wall thickness and operating conditions, ensuring correct fit and sealing performance once installed. This is particularly important on large-diameter or legacy metallic mains where dimensional accuracy and load distribution are critical to long-term performance. 

Radius Subterra delivers a complete service including manufacture, supply and installation of grouted tees and sleeves. These fittings are commonly deployed as part of live network interventions, including repair works, new branch connections, and as enabling components for flowstopping procedures.

By managing design, manufacture and installation under a single scope, Radius Subterra ensures controlled execution, reduced interface risk and confident delivery of structural, pressure-rated solutions. Comprehensive reporting and documentation are provided to support quality assurance and asset records, ensuring the operation is completed in a controlled and compliant manner.

Completion plugs

Completion plugs are manufactured and supplied by Radius Subterra for use with stopple tees and under‑pressure fittings. Completion plugs provide a pressure-retaining seal once stoppling or intervention works have been completed, allowing the fitting to remain in situ without the need for sacrificial valves.

Available in multiple configurations to suit different stopple machines and operational requirements, plugs can be manufactured to match bespoke tee designs and outlet dimensions. This ensures compatibility with the chosen isolation method and maintains the integrity of the main once operations are finalised.

Completion plugs are typically installed following a stopple or under-pressure drilling operation, providing a permanent mechanical seal within the branch outlet. Designs include screw-type, pin-type and mechanical locking configurations, selected based on machine compatibility and operational preference.

Plugs are manufactured with full material traceability and can be produced to suit a wide range of outlet diameters. Where required, bespoke configurations are available to align with specific network standards or project requirements.

As part of a wider intervention scope, Radius Subterra supports the complete process, from tee manufacture and installation, through isolation and drilling, to final plug installation and completion reporting, delivering a fully managed solution with documented assurance for gas and water network operators.

Our other solutions

Explore other Radius Subterra solutions designed to enhance safety, efficiency and long‑term performance.

Our other solutions

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Under Pressure Connections

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Pipeline Repair 
& Maintenance

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Under Pressure Connections

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Pipeline Installation 
& Mainlaying

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Pre-Insulated pipework

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Pressure Testing

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Pipe
Cutting

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Manufacturing/ Fabrication

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Engineering & 
Project Management

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Pipe Lining

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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.

Halzhausen

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

369071f5c6f096d955d9ac9560ce3672de6d3fac

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

Anglian Water North Walsham Rolldown pipe lining

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

Carnoustiehighstreet

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. 

Halzhausen

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

369071f5c6f096d955d9ac9560ce3672de6d3fac

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

Anglian Water North Walsham Rolldown pipe lining

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

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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

Ready to progress your next pipeline project? 

Radius Subterra’s specialist engineering teams are here to support you with safe, efficient and technically assured solutions across every stage of the asset lifecycle. 

Get in touch by phone or email to discuss your requirements and speak directly with our experts. 

Alternatively, complete the form below with the relevant information.

Pipeline Challenge Terms & Conditions

  1. The Promoter
    • The promoter is: Radius Subterra Limited, with registration number 01147475 and its registered address at Radius House, Berristow Lane, South Normanton, Alfreton, Derbyshire, DE55 2JJ.
  2. The competition
    • The title of the competition is Pipeline Challenge.
  3. How to enter
    • The competition will run from 09:00 BST on 29 September 2026 (the “Opening Date“) to 17:00 BST on 1 October 2026  (the “Closing Date”) inclusive.
    • All competition entries received after the Closing Date are automatically disqualified.
    • To enter the competition:
      • Entrants must scan the QR code displayed within the Pipeline Engineering Village at No-Dig Live 2026 at stand G56 and complete the online entry form.
      • Entries must include:
        • description of an industry challenge, operational issue or engineering idea;
        • relevant sector;
        • supporting background information;
        • entrant’s full name (first name and surname);
        • company name; and
        • email address.
      • No purchase is necessary and no payment is required to enter.
      • The Promoter will not accept:
        • responsibility for competition entries that are corrupted, not successfully completed or transmitted, lost, mislaid, damaged or delayed in transit, regardless of cause, including, for example, as a result of any postal failure, equipment failure, technical malfunction, systems, satellite, network, server, website, computer hardware or software failure of any kind; or
        • proof of posting or transmission as proof of receipt of entry to the competition.
      • By submitting a competition entry, you are agreeing to be bound by these terms and conditions.
      • Entries will be reviewed after the event by a judging panel comprising representatives of the Promoter and Flowstop Services Limited (“Judging Panel”). One winner will be selected. Entries will be assessed against the following criteria:
        • relevance to the pipeline and utility sectors;
        • potential industry impact;
        • originality; and
        • potential for development into a practical engineering solution.

The Promoter will take reasonable steps to ensure judges are independent of the entrants and that any conflicts of interest are declared and managed.

  1. Eligibility
    • Entries are limited to attendees aged 18 years or over of No‑Dig Live 2026 scanning the QR code at the event. The Promoter reserves the right to verify attendance.
    • The following cannot enter:
      • employees of the Promoter or its holding or subsidiary companies;
      • employees of agents or suppliers of the Promoter or its holding or subsidiary companies, who are professionally connected with the competition or its administration; or
      • members of the immediate families or households of (a) and (b) above.
    • In entering the competition, you confirm that you are eligible to do so and eligible to claim the prize. The Promoter may require you to provide proof that you are eligible to enter the competition.
    • Entries must primarily reflect the entrant’s own original analysis, reasoning and creative input. The Promoter may disqualify entries where it reasonably believes the submission has been substantially generated by artificial intelligence (including but not limited to chatbots such as ChatGPT or similar software applications).
    • There is a limit of one entry per person. Entries on behalf of another person will not be accepted and joint submissions are not allowed.
    • The Promoter reserves all rights to disqualify you if your conduct is contrary to the spirit or intention of the prize competition.
    • Competition entries cannot be returned.
    • By entering, you confirm that your entry is your own original work, does not infringe the rights (including intellectual property and confidentiality rights) of any third party, and that you have obtained any necessary permissions from your employer or any third party to submit the entry and to grant the rights described in clause 9.
    • Do not include confidential or commercially sensitive information in your entry.
  2. The prize
    • The prize is £200 worth of vouchers, redeemable at Amazon, subject to the issuer’s terms including any expiry date.
    • The prize is subject to availability. There is no cash alternative. The Promoter reserves the right to substitute the prize with a prize of equal or greater value.
    • The prize is not negotiable or transferable.
  3. Winners
    • The decision of the Judging Panel is final and no correspondence or discussion will be entered into.
    • The Promoter will contact the winner by email within 14 days after the Closing Date using the email address provided in the entry.
    • The Promoter will publish the winner’s name and company on LinkedIn within 21 days after the Closing Date (the “Announcement Date”)
    • If you object to any or all of your name and winning entry being published or made available, please contact the Promoter at Radius Subterra Limited, Radius House, Berristow Lane, South Normanton, Alfreton, Derbyshire, DE55 2JJ or email Radius.subterra@radiussubterra.com. In such circumstances, the Promoter must still provide the information and winning entry to the Advertising Standards Authority on request.
  4. Claiming the prize
    • Please allow 14 days for delivery of the prize by e-mail.
    • If the winner cannot be contacted, is not available, or has not claimed the prize within 14 days of the Announcement Date, the Promoter reserves the right to offer the prize to the next highest‑ranked eligible entry as determined by the Judging Panel from the entries received before the Closing Date.
  5. Limitation of liability

Insofar as is permitted by law, the Promoter, its agents or distributors will not in any circumstances be responsible or liable to compensate the winner or accept any liability for any loss, damage, personal injury or death occurring as a result of taking up the prize except where it is caused by the negligence of the Promoter, its agents or distributors or that of their employees. Your statutory rights are not affected.

  1. Ownership of competition entries and intellectual property rights
    • Entries will not be returned. Do not include confidential or commercially sensitive information in your entry.
    • For all entries, you grant the Promoter a worldwide, non‑exclusive, royalty‑free licence to use, review and evaluate your entry for the purposes of administering and judging the competition.
    • If you are selected as the winner, as a condition of receiving the prize you agree to assign to the Promoter, with full title guarantee, all intellectual property rights in your winning entry and to waive your moral rights in the winning entry. You agree to execute any documents reasonably required to perfect such assignment.
    • You warrant that your entry is your own original work, does not infringe any third‑party rights, and that you have all necessary rights and permissions to submit the entry and grant the rights set out in these terms.
  2. Data protection and publicity
    • The Promoter will process your personal data as controller for the purposes of administering the competition (including judging, winner notification and publication). Further details, including lawful bases, recipients, retention periods, your rights, and how to exercise them, are set out in our Privacy Policy available at Privacy Policy. See also condition 3 and condition 6.4, with regard to the announcement of winners.
  3. General
    • If there is any reason to believe that there has been a breach of these terms and conditions, the Promoter may, at its sole discretion, reserve the right to exclude you from participating in the competition.
    • The Promoter may void, suspend, cancel, or amend the competition where necessary due to events outside its reasonable control and will do so acting reasonably.
    • These terms and conditions are governed by English law. If any entrants to this promotion wish to take court proceedings, then they must do this within the courts in the United Kingdom.