After you cut a pipe, you will find a burr on the inside of the pipe. A pipe reamer is used to remove the burr in a process called reaming.
If the burr is left in the pipe, deposits will begin to collect inside the pipe and clog it, slowing the flow of liquid within the pipe.
One method of joining pieces of pipes together is to screw one pipe end into another screwed fitting, such as male and female fittings and couplings. For pipe segments to be joined in this way, the ends of the segments must be prepared by threading.
Threading entails passing something through or around a pipe segment to form grooves that allow another segment to be screwed onto or into it.
Galvanized pipes and black-iron (cast iron) pipes need to be threaded on the outside. To make clean cuts of these threads, use die tools. Dies must be sharp so that the threads they cut will be correctly tapered.
Apply cutting oil to the die tool to reduce the friction and heat caused by cutting. If there is too much friction or heat, the die tool will push the metal that is being threaded instead of making a clean cut. Heat and friction can also break the teeth off the die.
Pipe Threading Tools
Electric Pipe-Threading Machine
The electric pipe-threading machine rotates, threads, cuts, and reams pipe.
The pipe is inserted into the chuck of the machine, and the chuck is tightened. A foot pedal controls the machine. Use your foot to operate the pedal.
Do not place a piece of wood or other object on the pedal to depress it. For trouble-free operation, be sure to follow the preventive maintenance schedule provided by the machine’s manufacturer.
Soldering is the use of heat to form joints. It is generally used to join rigid copper pipe and fittings.
The filler material, called solder, is distributed evenly between the close-fitting surfaces of the pipes when the pipes are heated, and to the faces of the pipes when the pipes are heated to the necessary temperature.
A small, portable gas torch is used for soldering. Propane and acetylene are the two most commonly used gases. The torch heats the metal and the flux (also known as soldering paste) to join the pipe.
The torch flame produced by a soldering tool has different temperatures -- all of them hot, but some hotter than others.
The hottest part of any flame is at the tip of the inner cone, where the pale flame meets the deeper-colored outer flame.
Propane torches are used for soldering copper pipes.
Use a carbon-arc torch to solder copper, tinned and galvanized metal parts.
Click on the points below to know the steps involved in soldering metal items:
1 Overlap the parts to be soldered for best results.
2 To begin soldering, touch the carbon electrode to the metal, but do not draw an arc.
3 Hold the electrode in contact with the metal until the point becomes red hot.
4 When the metal becomes hot enough to melt the solder, drag the carbon electrode slowly over the metal. Feed in more solder as needed.
5 Do not lift the carbon electrode while soldering.
6 When you are finished, quickly remove the carbon electrode from the work. Avoid creating an arc.
Using Extension Cords
To function properly, a power tool must receive enough electrical energy. As electricity travels the length of an extension cord, it tends to lose voltage. This loss is called voltage drop.
When voltage drops, the tool has to draw more amperage, causing the motor to run hotter. If such unusual amperage draw continues for a prolonged period, the motor can overheat and be ruined.
Receptacles on the ends of extension cords are not part of the permanent wiring of the building. The next slide presents some basic guidelines to using extension cords safely.
Adhere to these basic job-site electrical safety guidelines:
• Use three-wire extension cords, and protect them from damage.
• Never fasten them with staples, hang them from nails, or suspend them from wires.
• Never use damaged cords.
• Make sure that the panels, switches, outlets, and plugs are grounded.
• Never use bare electrical wire.