ISO 9952:1993

Specifies the construction and performance requirements (classification, mechanism, installation, marking, valve body length, connections), and test methods (resistance to internal hydrostatic pressure, tightness, valve opening after tightness test, pressure loss, endurance, tightness after mechanical endurance test) for check valves of nominal sizes 15 mm (0,5 in) up to and including 300 mm (12 in) intended for operation with water at temperatures not exceeding 50 °C, which may contain fertilizers and chemicals of types and concentrations used in agriculture.