spare valve set的用法和样例：
- Each hot water space heating boiler shall be equipped with a pressure relief valve set to relieve below the maximum boiler working pressure.
- The valve set pressure is too close to the normal working pressure. Readjust the valve set pressure and pay attention to equipments' strength.
- On the set of processing simply valve set was attached to the lathe with 0 # Emery cloth at the expense of the gringing rarts of sanding.
- The helix-angel of intake ports is educed and valve set is a new design, the exhaust ports adopt the approximate circle shape cross-section as the exhaust pipe.
- Body has handhole (or manhole) for easy wash and examination, And bottle valve set up inlet/outlet valve,safety valve, pressure gauge and pressure gauge valve, drain valve etc.