Sets out the design, construction, performance and testing requirements of valves for pressure control, expansion control, pressure relief, vacuum relief, temperature relief and non-return functions. Applies to systems with static supply pressures up to 1600 kPa (163 mH2O) and working pressures up to 500 kPa (51 mH2O) with temperatures not normally exceeding 85 degrees C, installed to NZS 4603 and 4607. Referenced in BIA Approved Document G12.