At PPSL District Heating, we’re frequently called upon to carry out leak detection surveys on systems installed by other contractors – often on networks that are just a few years old. It’s a troubling trend and it points to a bigger issue in the industry: the consequences of cutting corners on quality during installation.
We recently surveyed a failing system that was only six years old. The price tag for rectifying the damage? An eye-watering £1.2–£1.5 million. Yet, with as little as £100–£150k more invested upfront in a competent contractor, better quality management and proper design practices, that outcome could have been entirely avoided.
Poorly installed HDPE outer casing joints are a key culprit. Failures here can allow moisture to penetrate the insulation layer, leading to corrosion of the steel carrier pipe and compromising the entire network. While weld failures do occur, more often we see issues with HDPE jointing – especially when shrink-fit sleeves are used incorrectly or without adequate oversight.
Modern district heating systems often incorporate leak detection wires embedded in the insulation. These systems depend on a dry, sealed environment to function accurately. If water gets in through a compromised joint, it can:
– Trigger false leak alarms – or worse, mask actual leaks
– Accelerate corrosion of the steel carrier pipe
– Degrade the insulation and reduce thermal performance
Even the best materials can fail without correct installation. Following manufacturer guidelines is critical to:
– Ensure a full waterproof seal
– Protect delicate leak detection wires from damage
– Comply with warranty and industry standards
When it comes to HDPE outer casing joints, contractors typically choose between two methods: fusion welding or shrink-fit sleeves. Here’s why fusion-welded joints are often the superior choice:
– Seamless, watertight bond: A continuous piece of HDPE offers the highest resistance to moisture ingress
– Durable and resilient: Better equipped to handle ground movement, pressure, and thermal expansion
– Low maintenance: Fusion joints last decades with minimal risk of failure
– Leak detection-friendly: Superior sealing means more reliable sensor readings and fewer false positives
While shrink-fit joints can be appropriate for low-cost or temporary installations, they require expert attention and rigorous quality control.
If you’re investing in a district heating network, don’t let short-term savings compromise long-term performance. Selecting a contractor with a proven track record, ISO 9001-certified quality management processes and fully accredited teams with on-site supervision is essential.
District heating systems are designed to deliver reliable energy for decades. By prioritising correct HDPE jointing methods and high standards at installation, you’re building a network that lasts.
Want to learn more or speak to our team about leak detection or quality assurance in district heating? Contact us today.
