A fire in the engine room can be caused by a leak at a fuel or lube-oil pipe-flange connection. Even the smallest leak can spray fine droplets of lube oil or fuel on nearby hot surfaces, such as the exhaust manifold of a diesel engine. To reduce this possibility, spray shields (flange safety shields) are installed on piping flanges of flammable liquid systems, especially in areas where the fire hazard is apparent. (See fig. 13-38.) The spray shields are usually made of aluminized glass cloth and are simply wrapped and wired around the flange. Additional information concerning the use and installation of flange safety shields is provided in Naval Ships Technical Manual, chapter 9480.

EQUIPMENT AND INSTRUMENT TAG-OUT

Whenever you make repairs to equipment, you will be required to isolate and tag-out the equip-ment of that section of the system. The tag-out program provides procedures to be used when a component, a piece of equipment, a system, or a portion of a system must be isolated for preven-tive or corrective maintenance. The tag-out

Figure 13-38.-Flange safety shields.

program also provides procedures to be used when an instrument becomes unreliable or is not operating properly. The major differ-ence between equipment tag-out and instru-ment tag-out is that labels are used for instrument tag-out and tags are used for equipment tag-out. Tag-out procedures are described in OPNAV-INST 3120.32B and represent the MINIMUM re-quirements for tag-out. These procedures are MANDATORY and are standardized aboard ship and repair activities through local written instructions.

SUMMARY

This chapter has provided you with an over-view of the pumps and valves you will be required to operate and maintain. Now that you have read the information in this chapter, you should understand the relationship of a pump or a valve to the system it serves. You should readily under-stand the necessity for keeping these components operating at top efficiency through proper maintenance. If you are uncertain concerning any areas of this chapter, go back and review the sec-tions with which you are having trouble before you go on to chapter 14.