District Heating NDT Inspection

SPECIALIST THIN WALL PIPE INSPECTION

District Heating (DH) Pipework NDT

At WHE NDT, we specialise in the inspection of thin-wall pipework commonly found in underground and over-ground District Heating networks.

Our team has developed advanced Phased Array Ultrasonic Testing (PAUT) and conventional Ultrasonic Testing (UT) methods that deliver highly conclusive and efficient weld inspections, even on challenging thin-wall systems.

We work closely with our customers to provide a Just-In-Time (JIT) inspection service, enabling projects to progress efficiently through:

excavation → pipe fitting → welding → NDT → sleeving → back-filling → reinstatement

minimising downtime and disruption.

Our District Heating projects operate across the UK and Ireland, with the majority undertaken locally within London.

Ultrasonic Testing (UT) & Magnetic Particle Inspection (MPI)

By employing our specially developed manual UT techniques, we achieve complete coverage of the weld root and body — inspection areas that are often difficult or impossible to assess using standard UT approaches on thin-wall pipework.

When combined with surface inspection using Magnetic Particle Inspection (MPI), this method provides a comprehensive, proven, and cost-effective inspection solution that is widely adopted by our clients.

Phased Array Ultrasonic Testing (PAUT) & Magnetic Particle Inspection (MPI)

PAUT combined with MPI is widely recognised as the most thorough and conclusive inspection method for District Heating pipework.

This approach provides full inspection of the weld root, body, and cap without the safety constraints, programme delays, and high costs associated with radiography (X-ray).

PAUT scan data is collected during inspection, assessed by qualified technicians, securely stored, and presented to the client as part of the inspection report.
Unlike manual UT, which uses a single probe firing one element at a fixed angle, PAUT probes fire up to 32 elements at multiple, configurable angles, sweeping the entire weld and heat-affected zone (HAZ) in a controlled and systematic manner.
When defects are identified, the clear visual presentation of PAUT data allows us to easily demonstrate defect location and size to both the client and on-site welders, enabling rapid and accurate repairs with minimal rework.

Raising Standards in District Heating

A clear industry trend is emerging towards the standardisation of 100% PAUT inspection for District Heating networks.

At WHE NDT, we are proud to be strong advocates of this approach, actively supporting our clients in adopting higher inspection standards and driving the next step forward in District Heating installation quality and reliability.

WHE NDT are proud Associate Members of the UK District Energy Association (UKDEA), the leading industry body representing organisations involved in district heating and cooling across the UK. Our membership reflects our commitment to supporting high standards, safety, and quality assurance within the energy and infrastructure sectors, while contributing specialist non-destructive testing expertise to heat network and pipeline projects nationwide.

Project Experience

London Projects

A1 Meridian Water
A2 Meridian Water
Anthems Way, Stratford
Abbey Road Development
Abbey Wood Development
Ashley Road Developments
B1 Meridian Water
Barking Heat Network
Blackhorse Lane Developments
Blackwall Reach Developments
Boston Road P1 & P2
Chobham Manor P1, P2, P3 & P4
Cherry Park, Stratford
Clapham Park Regeneration Scheme
Clapham Common
Colindale Gardens
Colindale Grahame Park
Copper House Green
Craik Court, Peel Development
ENGIE – Excel District Energy Centre
Enfield – New Avenue Heat Network
Elephant & Castle Heat Network
Elephant Park
Farringdon – Mount Pleasant Post Office
Greenford Green Developments
Golf Links Estate
Greenwich Design District
Greenwich GMV
Greenwich GMV400 Development
Hepworth Place Development
Imperial College London P1 & P2
Kidbrooke P1 & P2
King’s Cross P1, P2 & P3 (including Facebook & Google)
Thamesmead Developments
The O2 Greenwich / Millennium Dome (Main Line)
The Perfume Factory
Millbrook, London
Meridian Grande
Naylor Grove Heat Network
Nine Elms – US Embassy Connection
New Avenue Development
Nine Elms – One Thames City
North London Heat & Power
Park Royal – Regency Heights
Pool Street, Stratford
Ponders End
Queen Mary University of London
Silvertown Heat Network
Southmere, Thamesmead Regeneration P1 & P2
Springfield Hospital P1 & P2
St Silas Estate, Camden
St Anne’s Hospital Development
Stratford Waterfront (BBC, Sadler’s Wells, UAL London College of Fashion, UCL & V&A Museum)
Stratford International Quarter
Stone Hill Business Park
Summer Street, Southwark
Sugar House Island Development
Trinity Walk
Upton Park Development
U.S. Embassy
Walthamstow Forest Town Hall Development
Wandsworth – Old Homebase Site
Wandsworth – Old B&Q Site
Watts Park Heat Network
Westhorpe Gardens Development
West Ham Stadium Connections
Windmill Park