PPSL were engaged to design, supply and install the buried heating mains serving air handling units.
PPSL were appointed to design, supply and install new buried pre-insulated heating mains, including associated civil works, to serve an area of student accommodation at the University of Warwick.
PPSL installed approximately 12.5 km of heating pipework, varying in size from DN 25mm up to 200mm.
Working closely with the University Estates Department and the Consulting Engineers, Integrated Energy Utilities (IEU) who are based in Kingswear, Devon, PPSL planned the route of the mains to minimise the disruption to the working campus. IEU are retained by the University to upgrade the Energy Centre by installing combined heat and power units and utilising the waste heat to supply hot water to the campus heating systems and domestic hot water via plate heat exchangers to the accommodation buildings.
The installed system was manufactured by LOGSTOR of Denmark, designed to operate at 95ºC with a temperature drop across the system of 30ºC. The design utilised LOGSTOR’s “bonded” system with tried and tested techniques to absorb thermal expansion movement.
The bonded system is so named because the carrier pipe, polyurethane insulation and the HDPE jacket are bonded together and move as one unit when expanding. Expansion movement is restricted by the friction between the pipe jacket and the surrounding backfill.
The PU insulation contains copper wires to enable the pipework to be monitored for ingress of water into the insulation via a monitoring system.
In order to minimise the amount of open excavations, each weld was ultrasonically inspected for integrity enabling the welds to be insulated, sealed and backfilled as the installation progressed. On completion of an area, the pipe was flushed and hydraulically tested.