- - AGRICULTURAL CORE CURRICULUM - - (CLF2000) Advanced Core Cluster: AGRICULTURAL MECHANICS (CLF2550) Unit Title: PLUMBING ____________________________________________________________________________ (CLF2552) Topic: PLUMBING Time Year(s) FITTINGS 1 Hour 3/4 ____________________________________________________________________________ Topic Objectives: Upon completion of this lesson the student will be able to: Learning Outcome #: (L -3) - Understand the purposes for the various plumbing fittings and materials. Special Materials and Equipment: Examples or a chart of different types of fittings. References: Burke, Stanley R., & Wakeman, T. J. (1990). MODERN AGRICULTURAL MECHANICS (2nd ed.). Danville, IL: Interstate Publishers. Cooper, Elmer L. (1987). AGRICULTURAL MECHANICS: FUNDAMENTALS AND APPLICATIONS Albany, NY: Delmar Publishers. Editors of Reader's Digest. (1973). COMPLETE DO-IT- YOURSELF MANUAL (7th ed.). Pleasantville, NY: Reader's Digest Association. Ripka, L. V. (1978). PLUMBING INSTALLATION AND DESIGN. Alsip, IL: American Technical Publishers. RESOURCES: Black and Decker Home Improvement Library. (1990). HOME PLUMBING PROJECTS & REPAIRS. Available from: Cy DeCosse Inc., 5900 Green Oak Drive, Minnetonka, Minnesota 55343 1-800-328-3895 Evaluation: Unit Exam TOPIC PRESENTATION: PLUMBING Fittings A. Plumbing fittings have different shapes which allow rigid straight pipe to change both direction and diameter. Since the names of plumbing fittings derive from either their shape or their function, the names remain the same regardless of the material from which they are made. Fittings are generally divided into two categories: water supply or DWV. A description of the most common plumbing fittings follows: 1. Elbows are used to change the angle or direction of the pipe run. The most common elbows come in 90 degree and 45 degree turns. The sweep of the fitting describes how fast a transition or change in direction is made. Therefore--especially in DWV fittings--the long sweep fittings are chosen to avoid clogs. 90 degree elbows are generally called ells. 2. On street elbows, one end of the fitting has male threads and the other end has female threads. Street elbows are common in galvanized steel and copper pipe. They are convenient because they do away with the need for a nipple and work well in tight quarters. 3. Tee or T-fittings allow for branch lines. They are shaped like the letter T. DWV tees are known as waste or sanitary Ts. In these fittings the intersection is slightly curved in order to avoid clogs. Gradual bends are best for smooth flow of waste. 4. Couplings are used to join two straight pieces of pipe of the same diameter. 5. Reducers are used to join pipe of different diameters. Galvanized steel reducers are called bell reducers because they look like a bell. All reducers make a gradual transition between different diameters of pipe and therefore they take up considerable space. 6. Bushings are used to make the diameter of a pipe fitting smaller. They differ from reducers in that they make abrupt changes in diameter and take very little space. Two examples of galvanized steel bushings are face bushings, which take the least amount of space, and hex bushings which can be tightened with an adjustable wrench. 7. Unions are used to join pieces of pipe where pipes cannot be turned or when a piece of equipment may have to be removed for maintenance or replacement. 8. Adaptor fittings are used to change the end of a non-threaded pipe to male or female threads as needed. Adaptors are commonly used in copper and plastic plumbing jobs. 9. Caps are used to close the end of a dead end pipe. 10. Plugs close an opening on a pipefitting normally used for inspection and cleanout. 11. Nipples are short lengths (under 12") of pipe threaded at both ends. 12. Wyes (pronounced like the letter Y) are used primarily to gain inside access to DWV systems. B. Valves and Hose Bibs - Valves are used to control the flow of water or other fluids in a plumbing system. Common types of valves include the following: 1. A gate valve is a valve situated between the point of connection and the rest of the plumbing system. a. It usually remains wide open, but can be shut down in case repairs or additions have to be made to the system. b. A gate valve is not designed to be opened and closed on a regular basis. It has a movable wedge that is turned via a handle and spindle to regulate the size of the opening. c. Repairs are simple. Remove the handle and packing nut and replace the packing washer. Reassemble and install. Remember to check for leaks. Do not overtighten the packing nut. 2. A check valve allows the fluid in the pipe to flow in one direction only. a. Check valves are used in water wells to prevent the backflow of water. b. There are two basic types: swing or flapper and lift check valves. Both work automatically. 3. A globe valve is a valve used when frequent adjustment of the flow rate is necessary. a. It is a compression-type valve with a disk or washer that is compressed into a seat to form a tight seal. b. Repair is made by replacing the stem washer or disk. 4. A hose bib is a threaded exterior faucet that allows for the attachment of a garden hose or appliance hose. It can also be called a sillcock or hosecock. __________________________________________________________ ACTIVITY: 1. Make a collection of pipe fittings for a display board. Use steel, copper, and plastic examples. 2. Disassemble and compare a gate valve and a globe valve. 3. Repair a leaking hose bib. __________________________________________________________ 6/27/91 JD/JD/tf #%&C