AUXILIARY MACHINERY

Information related to much of the auxiliary machinery aboard ship is provided in Engineman 3 & 2, NAVEDTRA 10541 (current revision). This chapter provides additional information on the care and maintenance of compressed air systems and equipment, auxiliary boilers, hydraulic systems, distilling plants and pressure valves.

COMPRESSED AIR SYSTEMS

Qualifications for lower rates require that you know not only the purpose and principles involved, but also the operation and performance of routine maintenance on many auxiliary systems and units which use compressed air. As an EN, you have already used compressed air for such jobs as starting diesel engines, blowing out and cleaning various units, and operating numerous pneumatic tools. When working with any of the three types of compressed air systems (low, medium, and high pressure), you have probably found that the principal source of many troubles is to be found in the compressor. Even though the design and capacity of compressors vary, the maintenance procedures are essentially the same for all of them. However, the care and maintenance of high pressure compressors require additional safety precautions and adherence to procedures recommended by the manufacturer.

Because of your past experience, parts of the following discussion will serve only as a review, while other portions of the discussion will benefit you in your study for advancement, and will be helpful when you are called upon to train others. To avoid unnecessary damage to equipment, always use proper tools and take all necessary precautions. The correct use of proper tools should be kept constantly in mind when a machine of any kind is being serviced. Remember, the improper use of tools and methods may cause serious casualties to both machinery and personnel. Although rugged and dependable, modern auxiliary machinery is not designed to withstand abusive treatment. Gasketed joints, pipe joints, and bolts are designed to safely withstand the strain required for a tight connection when the specified torque is applied with the correct tool. Whenever a joint or bolt cannot be tightened without the use of an oversized wrench or wrench handle extension, there is usually something wrong with the assembly.

Pounding on a wrench to acquire additional force usually results in damage to the equipment.

Use of a wrench extension is likely to distort the gasketed surface or twist off the bolt without achieving a tight joint. The application of any force in excess of the force prescribed usually results in breakage.

CARE AND MAINTENANCE OF AIR COMPRESSORS

To keep the ships air compressors operating efficiently at all times and to prevent as many troubles as possible, it is necessary to know how to care for air intakes and filters; how to main-tain and replace air valves; how to take care of air cylinders, pistons, and wrist pins; how to adjust bearings and couplings; and how to properly maintain the lubrication, the cooling, the control, and the air systems.