25 x 25 mm Polyguard Barrier Pipe and fittings have been designed to deliver safe drinking water through redeveloped sites that may have been contaminated by previous industrial use. Conforms to Type A:WIS 4-32-19:2008 polyethylene pressure pipe systems with an aluminium barrier layer for potable water supply in contaminated land. Complies with BS 6920:2000 water quality testing. Approved under Regulation 31 of the water supply (water quality) regulation 2000. Polyguard to MDPE straight coupling compression.