NOTE

Never leave your toolbox or individual tools adrift where they could become a missile, fallen object, or tripping hazard and cause injury to personnel nearby. To keep track of your tools, the NCF tool kits contain inventory sheets. When you receive a kit that does not contain an inventory sheet, request a sheet from CTR. Figure 3-1 shows a partial inventory listing of a plumber's kit.

USE EACH TOOL ONLY ON THE JOB FOR WHICH IT WAS DESIGNED. When you use the wrong tool to make an adjustment, the end result will probably be unsatisfactory. For example, if you use a socket wrench that is a trifle too big, you will round off the corners of the wrench or nut. If this rounded wrench or nut is not replaced immediately, the safety of your equipment may be jeopardized in an emergency.

KEEP YOUR TOOLS WITHIN EASY REACH AND WHERE THEY CANNOT FALL ON THE FLOOR OR INTO MACHINERY. Avoid placing tools anywhere above machinery or electrical apparatus. Serious damage can result when a tool falls into the machinery after the equipment is energized.

NEVER USE DAMAGED TOOLS. A battered screwdriver may slip and spoil the screw slot, damage other parts, or cause painful injury. A gauge strained out of shape can result in inaccurate measurements.

Remember, the efficiency of a craftsman is determined to a great extent by the condition of his or her tools and the manner in which they are maintained. Anyone watching a skilled craftsman at work notices the care and precision with which tools of the trade are being used.

The care of hand tools should follow a pattern similar to personal articles; that is, always keep hand tools clean and free of dirt, grease, and other foreign matter. After use, return the tools promptly to their proper place in the toolbox. Improve your efficiency by organizing tools in such a way that those used most frequently can be reached easily without digging through the entire contents of the toolbox. Avoid accumulating unnecessary junk.

Q1. You should always use tools safely and in what manner?

Q2. Tool kits available in an NMCB are listed in what NCF inventory?

UNDERGROUND SANITARY PIPING

LEARNING OBJECTIVE: Recognize the different types of piping and methods for measuring, cutting, and joining sanitary piping.

The main purpose of a sanitary sewage collection system is to transfer sewage from the source to the sewage treatment plant. Raw sewage that is not transferred safely to a sewage treatment plant can harm human beings because it contains harmful bacteria.

The sanitary sewage collection system includes all house sewers, laterals, branches, interceptors, force mains, and so on. In this section of the chapter, we are primarily concerned with materials and operations required in the installation of sewer systems.

The installation of an underground sewer system for transferring domestic sewage from the source to the sewage treatment plant includes (1) trenching and grading, (2) measuring and cutting pipe, (3) laying pipe, (4) joining pipe, (5) testing, and (6) backfilling and tamping.

TRENCHING AND GRADING

Underground pipe requires excavation, either manually or with heavy equipment, depending primarily on the size of the job and the type of soil to be removed. On a large job where the soil is suitable for machine work, your project supervisor arranges to have Equipment Operators operate those pieces of equipment necessary to excavate or dig the trench. When it is impractical to use machines, you must do the job with a pick and shovel. Whichever method is used, the trench must be dug wide enough (2 feet minimum) to allow ample working room to join pipe sections. The bottom of the trench must also be sloped in the direction of flow, so sewage traveling through the pipeline laid in the trench is not restricted. On most jobs, an Engineering Aid is on hand to check elevations to ensure that the slope of the trench is close to the slope where the pipe is to be laid. On most jobs, Engineering Aids establish a system of batter boards and grade bars (explained later) for you to check the slope of the pipeline accurately, as it is being laid in the trench. Check the job specifications for the proper grade of the sewer line being installed. When specifications are not available, a rule of thumb is to