MDPE stands for Medium Density Polyethylene and MDPE Pipe Fittings are mainly used as cold water supply pipe, often in blue or black. It is often seen as the incoming supply pipe to modern domestic pipe installations or remote installations where copper is not suitable. Sizes available are 20mm, 25mm, 32mm, 50mm and 63mm and pipework is generally supplied in coils of 25 metres, 50 metres, 75 metres or 100 metres.
Fittings are available in three styles, either brass compression type where the pipe is inserted in the fitting and tightened with grips similar to a standard copper compression fitting. The fitting is supplied with an olive and it is important to use an MDPE pipe insert inside the end of the pipe to maintain the pipe shape and allow the fitting to seal properly. Compression fittings are also available in plastic where the fitting is screwed tight by hand to form a good water and mechanical connection. Other types of MDPE pipe fittings are push fit where the pipe is simply pushed into the fitting and the design creates a strong water and mechanical connection, using the water pressure to strengthen the seal. Again the use of pipe inserts is essential to maintain the pipe shape and ensure a proper connection
Many different types of fittings are available – MDPE Couplings, MDPE Reducers, MDPE Elbows or bends and MDPE Tees. MDPE to Copper converters are used for connecting MDPE pipe directly to copper pipe, either 15mm or 22mm, MDPE Stopcocks or stoptaps also allow water isolation, MDPE Stop ends are used as a temporary or permanent pipe termination. Some supplies also sell MDPE to Lead or Galvanised Iron fittings for connecting to older pipework and MDPE Tank Connectors to connect MDPE Pipe directly to a water tank. MDPE wall elbows will allow connection of MDPE directly to a bib tap and MDPE double check valves inserted in the MPDE pipework will prevent backflow and allow compliance with local water by-laws. In the event of the MPDE pipe becoming damaged a MDPE repair connector can be used as a temporary fix. Most push fit MDPE fittings utilise a rubber O ring and Grip Ring to form the connection and by replacing these two components the fitting can be re-used by removing the pipe from the fittings using Plastic or Metal Extractors.
Stop cock chambers are also available which are buried with the stopcock at the bottom of the hollow chamber and a hinged lid backfilled at a finished level to access the stopcock, with access at a flush finish to floor level.
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