Most shipboard systems and machinery are protected by pressure or temperature control devices. Their maintenance and operation are the responsibility of the EN1 or ENC on duty. Of the various types of pressure and temperature con-trol devices, the temperature control regulator, the relief valve, and the reducing valve are the types that you will encounter more often. Since temperature regulators were discussed in an earlier chapter, we will not cover them in this chapter. We will discuss only the relief valve and the reduc-ing valve. Remember, the information given in this chapter is general. More detailed information can be obtained from the manufacturers technical manual.

All reducing valves should be inspected, cleaned, and repaired semiannually, or whenever they do not operate properly.