Valves
(236)
Sanitary Ware
(74)
Pipe Fitting
(45)
Abstract: from the heating / ventilation / air conditioning system, two hot water heating coil valve in the second period of service failure. Among them, one is 353 copper alloy 19mm (3 / 4 inch) valve, a 360 copper alloy 13 mm (1 / 2 inch) valve, to a certain growth rate of failure. Failure is subject to change handle and bearings. Visual inspection shows a serious lack of local metal to form deep groove, deep groove present smooth corrugated surface. Metallographic analysis showed that the deep groove area uniform metal loss. No evidence or selective chemical attack of grain boundary corrosion. Recommended high-copper brass, copper-nickel alloy or Monel alloys for use in bearings and turn the valve handle Office, there are open or closed position in the entire office operation of the valve.
