This International Standard specifies the required properties and test methods for mechanical fittings intended to join polyethylene pressure pipes of nominal outside diameters not greater than 160 mm, used in water supply systems conveying potable water and water for general purposes at temperatures up to and including 40 °C. The nominal pressure of the specified mechanical fittings corresponds at least to the PN of the water supply system for which they are designed and is usually of PN 6, PN 10 or PN 16.