I have to replace a leaking flexible drain pipe on my bath, i thought i would put a solvent weld socket on the grey plastic pipe as access is poor, this pipe runs through the outside wall, but i found the OD of this pipe was 41mm and the the other white fittings were 42.5mm OD, can i use a solvent weld socket on the smaller pipe or will i have to use pushfit or compression fittings ?