You should observe the following general precautions relative to the application and maintenance of insulation:

1. Fill and seal all air pockets and cracks. Failure to do this will cause large losses in the effectiveness of the insulation.

2. Seal the ends of the insulation and taper off to a smooth, airtight joint. At joint ends or other points where insulation is liable to be damaged, use sheet metal lagging over the insulation. You should cuff' flanges and joints with 6-inch lagging.

3. Keep moisture out of all insulation work. Moisture is an enemy of heat insulation just as much as it is in electrical insulation. Any dampness increases the conductivity of all heat-insulating materials.

4. Insulate all hangers and other supports at their point of contact from the pipe or other unit they are supporting; otherwise,

a considerable quantity of heat will be lost via conduction through the support.

5. Keep sheet metal covering bright and unpainted unless the protective surface has been damaged or has worn off. The radiation from bright-bodied and light-colored objects is considerably less than from rough and dark-colored objects.

6. Once installed, heat insulation requires careful inspection, upkeep, and repair. Replace lagging and insulation removed to make repairs as carefully as when originally installed. When replacing insulation, make certain that the replacement material is of the same type as had been used originally.

7. Insulate all flanges with easily removable forms. These forms are made up as pads of insulating material, wired or bound in place, and the whole covered with sheet metal casings, which are in halves.

8. Asbestos control: Inhalation of excessive quantities of asbestos fibre or filler can produce severe lung damage in the form of disabling or fatal fibrosis of the lungs. Asbestos has also been found to be a casual factor in the development of cancer of the membrane lining the chest and abdomen. Lung damage and disease usually develop slowly and often do not become apparent until years after the initial exposure. If your plans include a long and healthy Navy retirement, you have no business doing asbestos lagging rip-out without proper training, protective clothing, and supervision. Most systems of today's modern Navy have been purged of asbestos and an asbestos substitute material installed in its place. Some of the older class vessels may still have some asbestos insulation installed. Use caution when handling lagging and insulation from these vessels. If in doubt, contact your supervisor and request the medical department conduct a survey of the material in question.

SUMMARY

This chapter has given you general information on pumps, valves, and piping. It would be a good idea to get some hands-on experience aboard your ship. Trace various systems out and see how they are set up. Ask your LPO to explain the systems and how each part in the system works. The key phrase here is ASK QUESTIONS!