Union Plain x Plain Description Plain unions are designed to join two PVC pipes together with the use of solvent weld cement. The threaded union enables the assembly to be readily dismantled for the purposes of inspection or maintenance. No special tools are required. Sizing - Solvent Weld Pipe & Fittings Imperial (inch) PVC pipe and fittings sizing is not straightforward. They are sized by their nominal bore or approximate inside diameter. The following table details pipe outside diameters (o.d.) for each imperial size. The inside diameter (i.d.) of the socket end of the corresponding fitting will be the same as the outside diameter of the pipe. Pipe Size 1/2" 3/4" 1" 1 1/4" 1 1/2" 2" 2 1/2" 3" 4" Outside Dia mm 21.4 26.7 33.6 42.2 48.3 60.3 75.2 88.9 114.3 Sizing - BSP Threads The following table details approximate thread diameters for male BSP threads. Nom Pipe Size 1/2" 3/4" 1" 1 1/4" 1 1/2" 2" 2 1/2" 3" 4" Thread Dia mm 21.0 26.4 33.2 41.9 47.8 59.6 75.2 87.9 113.0 Pressure Rating PVC solvent weld fittings (sizes 1/2" to 8") have a pressure rating of 15 bar (215 psi) at 20oC. PVC threaded fittings (1/2" to 4") have a pressure rating of 12 bar (170 psi) at 20oC As temperature increases the pressure rating is reduced. PVC systems should not be used where temperatures exceed 60oC.
