tighten the chuck jaws and rear centering jaws. Put the tool support bar in a position to support the cutter handle. Next, apply the cutter to the pipe as though you were cutting it manually. Let the cutter handle rest on the tool support bar. Ensure the cutter wheel is exactly on the mark where the pipe is to be cut. Now, tighten the cutter blade so it contacts the pipe. The next step is to turn the power switch to the FORWARD position. Continue turning the cutter blade into the pipe until the cut is completed.

After the pipe has been cut, it can be reamed with the same machine. To ream the pipe, place the reamer in the pipe end. Let the handle of the reamer rest against the tool support bar. Turn on the motor. Press the reamer into the pipe as needed to remove the burr.

The machine can also be used for threading pipe. First, insert the pipe into the front or the rear of the machine. Let the pipe extend out of the speed chuck far enough so the threader clears the chuck during threading. Next, center the pipe in the speed chuck and close the jaws with a snap spin of the handwheel. If the pipe extends out the back of the machine, close the rear centering jaws. Then place the threader on the pipe in the usual way. Pull out the tool support bar to the desired position and allow the threader handle to rest on the tool support bar on the switch side. Hook the safety latch over the handle. Now turn on the switch and proceed to thread the pipe. During the threading operation, remember to use plenty of cutting oil. In addition to the machine shown in figure 3-60, figures 3-61 and 3-62 show other types of power pipe machines and their accessories.

JOINING. - THREADED PIPE JOINTS are used on galvanized steel, galvanized wrought-iron, and black iron pipe. This method of pipe joining involves connecting threaded male and female ends.

To obtain a tight-threaded joint, be sure the threads are clean and in good condition. If the pipe has been exposed to the weather or banged around, check the threads carefully. When necessary, run a die over the threads to straighten the damage.

After securing the pipe in a vise, you must clean both ends with a wire brush. Then apply a good thread lubricant on the male pipe threads. You should always use a Navy-approved nontoxic compound for water pipes or antisiezing tape and mixed powdered graphite and oil for steam pipes. Do not apply pipe dope inside the pipe fitting, or you will foul the system.

Start the joint by hand and turn it up as far as you feel it will go. Now, slowly screw the remaining section of the pipe into the joint and tighten it with a pipe wrench. Do not use a hickey, or oversized wrench, or too much pull. Not all of the male threads should be screwed into the joint. If all the threads are used, the

Figure 3-61. - Power drive with accessories.