What is different about Schedule 40 pipe and fittings?
Schedule 40 (sometimes abbreviated to Sch40) is a North American pipe standard similar to the European classification system. In the European system, however, the pipe is grouped into "classes" of the same pressure rating. The ASTM Schedule system works in a different way in that it relates to the wall thickness and bore of the pipe and has inherited its measurements from steel pipe systems. The result is that unlike the Classification of European pipe, in which everything in class C has an operating pressure of 9 bar, the pressure rating of Schedule 40 pipe changes for each size, although the minimum working pressure is still 9 bar - for example 1" pipe has a pressure rating of 31bar, 1 1/4" pipe a rating of 25.5bar, with working pressures only reaching 9 bar at sizes of 12" and over.
In North America (as well as some other parts of the world) the colour of standard PVC pressure pipe is white. Hence, when this range of pipe and fittings are imported to the UK, they come in as white pipe and fittings rather than grey. Incidentally, Schedule 80 pipe and fittings, which are a higher pressure rating than Schedule 40, are usually manufactured in grey. We also import these, however, this is often on a to order basis.