Specifies the characteristics of cast iron swing-type check valves (wafer or flange type ) that have a nominal size in the range 40 mm to 60 mm and that are intended for general hydraulic (water, air, gas or petroleum) applications at working pressures
SANS 1551-1:2008 history
2008SANS 1551-1:2008 Check valves (flanged and wafer types) Part 1: PN series
2000SANS 1551-1:2000 Check valves (flanged and wafer types) Part 1: PN series