Durapipe is part of the Aliaxis Group and one of a number of brands including Marley, GPS, Philmac and FIP. In fact recently, due to various takeovers, mergers etc., many Durapipe fittings seem to now be supplied with FIP stamped on them.
Most industrial plastic pipe system are interchangeable between manufacturers, although sometimes this is with the exception of ball valves and unions, due to the type of threads used. As long as the same size of pipe and fittings are ordered, then durapipe fittings will fit other manufacturers pipe, and other manufacturers pipe will fit Durapipe fittings.
So why would you want to change from Durapipe? It is true that it is a good quality product, and until fifteen or twenty years ago, along with George Fischer, was one of the few reliably manufactured systems. Since that time however, with improvements on manufacturing processes and raw material quality, other manufacturers have improved their quality and reliability to the same level. This is born out by the WRAS (Water Reasearch Advisory Board) approval - which is a series of tests carried out by independent laboratories to ensure that the pipe systems are suitable for drinking water use by the water authorities - which is now given to many other manufacturers. Durapipe and George Fischer have, however, maintained their prices at a higher level than other manufacturers - sometimes at more than twice the price.
So, I summary, as we said at the start of this, if you want Durapipe we are more than happy to supply this to you at a competitive rate, however if you want to save some money without compromising your system, we are equally as happy to supply you an alternative manufacturer.