On exaple of Cartridge Heaters...

Cartridge Heaters and the Fabrication of Plastic Water Pipes

Drinking water supply methods have come a long way in Britain since the introduction of aqueducts by the Romans some 2000 years ago and, today, it is perhaps somewhat taken for granted that whenever you want a cup of tea or a glass of cordial, fresh drinking water is readily available at the twist of a tap.

Modern water supply pipework is manufactured from polymers such as polyethylene. Plastic gives a number of advantages in water supply demands, including that it is resistant to corrosion from the underground environment, it assists in the purity of the water, is durable and flexible.

Plastic water pipes not only supply water to new builds, both commercial and residential, but also have an important role to play in ensuring continuity of reliable water supply to established buildings, most often fitted with old cast-iron pipework installed in the Victorian era. Although these pipes have served their purpose well, with increased ground movement i.e. road traffic and heightened demand, they are prone to leakage or bursting.

The manufacturing method of pro-file extrusion is widely used in the forming of plastics materials and due to the process being continuous, long lengths of a product can be efficiently fabricated making it ideal for the manufacture of water pipes for water supply networks. Cartridge heaters assist in the process by helping melt plastic pellets into a molten state where it is then pushed by a barrel encased screw (heated by external heating elements) and forced through a die to create the desired continuous profile. Various finishing processes are subsequently applied, such as vacuum calibration and the cutting the pipes to specified lengths.