Hot water central heating system - has small dia. copper pipes with flow and return within common casing

摘要

Two small bore copper pipes (5) are placed side by side and each is covered with a layer of insulating material such as polyurethane foam (6). The two layers of insulation are pressed firmly against each other and wrapped round with an outer layer (7) of polyethylene sheet. This makes a compact flexible twin tube for flow and return. The flow and return from the boiler are taken to headers and separate twin tube assemblies are run from the headers to each radiator. At the ends where connections are to be made the covering and insulation can be easily cut so that the two pipes can be pulled apart.