If a spring-loaded reducing valve fails to operate properly, the trouble may be due to one or more of the following causes:

1. The adjusting spring may have taken a per-manent set. Readjust it or install a new spring.

2. The diaphragm may be damaged or ex-cessively deformed. Install a new diaphragm or, if the deformation is slight, make a proper adjustment of the adjusting spring.

3. Leakage may be caused by failure of the main valve or the auxiliary valve to seat properly.

Check the valves for wear and for the presence of dirt or scale. Correct the trouble by cleaning and grinding-in the main valve and the auxiliary valve. After grinding-in the auxiliary valve, the auxiliary valve stem may be too long. If it is too long, face off the end of the auxiliary valve stem until the proper clearance is obtained between the diaphragm and the end of the valve stem.