This course presents information on the detection and repair of water lines, the purpose of temporary repairs, types of clamps, and installation procedures for clamps. Learning how to properly make repairs on interior water distribution and waste systems and knowing about the associated safety hazards are of major importance in your job. Repair these systems correctly the first time, and it will pay off in the long run.
When you complete the work in this manual, you will be able to:
A water supply system is designed to operate under a specified pressure. When the recommended pressure is above or below what the system was designed for, problems may arise.
Customer notification is really a two-way process. First, the customers are notified by the utilities personnel of a water outage or lack of water pressure to their home or business during a repair to a water main or related components. The second way is for the customers to notify utility personnel of the lack of water pressure to their buildings. When the customer service desk is notified, then the customer service personnel will notify utilities personnel of the lack of pressure, or a possible water main break. Another indication of a possible water main break is when the water plant operator notices that the pressure gauges suddenly drop, for example, from 55 psi to 35 psi.
Identifying the affected area is not always a complicated process. The most common method of identification is when a customer calls to report the decrease in water pressure.
There are many reasons for pressure loss in a plumbing system. One reason could be that a valve was closed to the building, or maybe someone has opened a fire hydrant. Your job is to determine why there is not enough pressure in the system.
Once you have arrived at the job site, you should ask yourself the following questions: Did someone open up a main water system before your site? Did a worker close a valve shutting off the water supply to the building? Remember, if a water main break occurred previously, there may be rocks or pebbles in the system. This can cause a lot of problems, and as a last resort, you may have to dig down to the water main or service line and clear out any obstructions.
Locating leaks in an interior plumbing system is one of the many jobs that you will have. The first thing you want to do is isolate the leak. Some leaks are obvious when you arrive at the job site. You may have water is flowing from the ceiling or a wall. So, the first thing you want to do is isolate the leak. This is the easy part because you will know where to start your repairs. The difficult part is to locate a leak that is flowing between two concrete walls or from under a concrete floor, and the water is not visible at the break but is only visible somewhere else. This is because water takes the path of least resistance.
When locating leaks in a system, the first thing to do is to locate the area from where the most water is coming. After finding the main flow of water, you have to determine if the water is coming from a broken pipe at that location, or from somewhere else. Another way to detect a leak is to listen for the sound of water spraying in the wall or for a constant dripping sound inside the wall. If there is a possibility of a leak but you are not sure and the area is dark or unlit, you can place a piece of paper under the suspected leak and listen for a dripping sound or inspect the paper for the presence of water.
There are two types of repairs: temporary and permanent.
There are several reasons for making temporary repairs:
Repairing leaks and broken pipes is a task that utilities specialists will face daily. Because of the wide variety of materials used on piping systems, you must take care when attempting to repair them. We have already discussed factors that may require you to make temporary repairs until a more permanent repair can be made. We will now discuss the removal and replacement of piping and fittings and the methods of making temporary and permanent repairs on various types of piping.
Steel. Steel pipe can be temporarily repaired by using an emergency pipe clamp (Figure 3- 1). Fasten the clamp around the pipe until a permanent repair is made. To make the repair, position the clamp so that the gasket covers the hole. Close the clamp around the pipe. Insert bolts and tighten the nuts finger tight. Use a wrench to completely tighten the bolts. This clamp can be used either aboveground or underground. Remember that emergency repair clamps are for temporary use only.
Figure 3-1 — Emergency pipe clamp.
Copper. Make temporary repairs on copper tubing with a pipe clamp sometimes referred to as a “band-aid.” Place the clamp around the copper pipe and over the leaking area. Tighten the bolts until the leak stops.
Cast Iron. Full circle clamps and split repair clamps are two means of temporarily repairing cast iron pipe. These clamps usually come in lengths of 6 to 30 inches. They have a rubber gasket that goes around the inside of the band. The ends of the gasket are tapered where it overlaps in order to form an overlapping seal of consistent thickness. The band is usually made of stainless steel. The ends of the band have lugs attached. The split repair clamp consists of two bands and two sets of lugs. These lugs have holes in them for the bolts. Some clamps have slots instead of holes on one of the lugs. The slots make installing the bolts easier. Before installing the clamp, clean the pipe of all dirt or rust. Figure 3-2 shows a full circle clamp. Figure 3-3 shows another fitting used as a temporary repair on cast iron pipe, a bell joint clamp. Use the bell joint clamp to repair leaks at caulked joints or fittings.
Figure 3-2 — Full circle clamp.
Figure 3-3 — Bell joint clamp.
Plastic Use pipe clamps and full circle clamps to make temporary repairs on plastic pipe. Remember to use the proper size clamp. You may need to measure the OD of the pipe to ensure you get the correct size.
Permanent repairs are better than temporary repairs. Make a permanent repair in a manner that will function just as well as the original installation.
Use unions when making a permanent repair. Cut out the damaged section (at least 4 inches from the fittings) and remove it. See Figure 3-4, View A. Cutting the pipe at least four inches from a fitting gives you working room to thread this length and use it when you reassemble the pipe. The new section is made up of two lengths of pipe, one of which may be part of the old pipe and a union, which, when assembled, equals the length of the old pipe (Figure 3-4, View B). Install a single length of pipe only when the old length of pipe is disconnected at a union. Follow a similar procedure when cutting a branch into an existing line, except that a T-fitting is required between two new lengths, (Figure 3-4, View C). This assembly must also be equal to the original length of pipe that was removed.
Figure 3-4 — Replacing a section of pipe.
You must drain all the water from copper tubing before trying to repair it. Cut out the damaged portion of tubing with a tubing cutter or hacksaw. Pattern a new section of tubing using measurements from the damaged section. Then use copper couplings to position the new section into the system. Each end of the tubing should have a coupling on it. Use proper soldering procedures to ensure that the repair will be leak-proof. After you finish, test the repairs for leaks. However, if the system uses compression type joints, just tighten the affected ones with a wrench. When making repairs to a copper hot water line, ensure the heat source to the water heater is off before draining.
Cut out the damaged section of pipe. Try to make the ends of the pipe as straight as possible. Clean the ends of the pipe thoroughly. This will help strengthen the seal between the pipe and the compression couplings. Measure and cut a new section of piping. Use compression couplings to insert the repair pipe into the system. Figure 3-5 shows the components of a compression coupling.
Figure 3-5 — Compression coupling.
The procedures for installing a compression coupling are as follows:
Permanent repairs to plastic pipe are quick and easy:
Leaks in piping and at fittings are common. Since many joints are made in the middle of a system, you cannot just unscrew a defective fitting or piece of piping and replace it with new materials. Each type of piping has certain fittings and procedures for making a repair.
A water main break can cause a pressure loss and is considered a leak. This is apparent when customers call in large numbers to report a pressure loss. When you arrive at the area where the pressure loss was identified, you will most likely find water gushing from the ground. But when only one customer calls, the problem may be isolated to a single residence.
A broken water main or just a broken water supply line can cause leaks. Another cause can be poorly fitted joints or bad seals in valves. It will be your job to determine why there is a leak in the system.
On the job site, finding a leak may be fairly easy, but determining the cause can be difficult. Seeing the leaking water is only half the battle. You need to determine the answers to certain questions. Why did the pipe break? Did the pipe freeze? Why is the faucet dripping? Is the washer worn out? Once you have determined the cause, making the repair will enable you to be sure that the problem is solved.
|Test Your Knowledge
1. There are two types of leak repair.
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Locating and repairing leaks on interior waste systems are two common jobs that you will have. You first need to locate the leak, then gather your materials, and lastly, make the repair.
There are three common ways to locate leaking pipes: the visual inspection, the smoke test, and the peppermint test. These tests can be used on all types of pipes.
The Visual Inspection
If the drain line runs along the wall, water or water stains will indicate where the leak is. The smell of sewer gases will indicate a leaking drain line. At times, you may need to crawl under the building to inspect the piping.
The Smoke Test
First, plug off the entire system using drain plugs or caps. Next, introduce smoke into the system with a smoke machine or use a smoke pellet. When smoke appears at the vent(s) on the roof, plug them. Then, add ˝ psi to the system. Wait 15 minutes before you start the inspection. Ensure that a pressure gauge has been installed on the system for monitoring purposes. The smoke leaking from the broken pipe will reveal where the break is located.
The Peppermint Test
After the system has been completely plugged off (as described above) add peppermint to the system. Pour 2 ounces of peppermint oil down each vent. If the building is over 5 floors, then add another ounce per vent for the next 5 floors. Remember:
Once the peppermint oil has been added to the system, pour 5 gallons of hot water into each vent. Close off the vents. If there is a leak in a drain system, the peppermint odor will reveal where it is. Always use two people to conduct this test because the peppermint oil smell is so strong that the individual adding the peppermint will become less sensitive to the smell. After locating the leak, make the necessary repairs.
When making repairs to a drainage system, always replace the old or broken pipe with the same type of material. Of course, when replacing the entire piping system, you will use the material that has been specified for the job.
Repairs on an interior drainage system will be different depending on the type of piping and the type of joints used. There are two types of pipe primarily used on interior drainage systems: cast iron soil pipe (CISP) and plastic pipe.
Cast Iron Soil Pipe
Cast iron soil pipe is usually repaired by using compression joints or no hub joints.
Assembling Compression Joints. This type of joint uses a bell and spigot. It is sealed with a neoprene rubber gasket. When the spigot end of the pipe and the neoprene gasket are lubricated and pushed or drawn into the gasket hub, the joint is sealed by displacement and compression of the rubber gasket.
Assembling No Hub Joints. This type of joint uses a one piece neoprene gasket and a stainless steel shield and retaining clamps. The advantages of this type of joint are that joints can be made in confined spaces, joints can be made quickly, and few tools are required. The disadvantage is that extra hangers are required. These types of junctions should not be buried or put into inaccessible areas.
Making repairs on PVC drainage systems is not difficult
Once joined, allow the joints ample time to dry as prescribed by the manufacturer’s directions. No hub couplings may also be used to repair PVC drainage systems since CISP and PVC have the same outside diameter.
Cast Iron Pipe
Cast iron soil pipe is heavy. You will need assistance on repairs. When cutting out the damaged section of cast iron with a snap cutter.
It is necessary for you to wear safety goggles and gloves, and have your sleeves rolled down because of the danger of flying pieces of cast iron.
Plastic pipe is light, inexpensive, durable, and easily assembled. The dangers involved with solvent gluing are the fumes from the cleaner and the solvent cement. Also, the chemicals in the cleaner and solvent cement are highly flammable.
The area in which you are working these solvents require adequate ventilation. Also, keep open flames away from the cleaner and solvent cement.
|Test Your Knowledge
2. What is a disadvantage of the no hub joint?
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This course presented information on the detection and repair of water lines, the purpose of temporary repairs, types of clamps, and installation procedures for clamps. Learning how to properly make repairs on interior water distribution and waste systems and knowing about the associated safety hazards are of major importance in your job. Repair these systems correctly the first time, and it will pay off in the long run.
- To Table of Contents -
1. Why is it difficult to pinpoint a leak where water is flowing between two concrete walls?
2. What is another name for a temporary repair device used on copper pipe?
3. How many means of temporarily repairing cast iron pipe are there?
4. What two clamps are used to temporarily repair a CISP?
5. When repairing a steel pipe, how many inches from the damaged section do you make the cuts?
6. Other than a broken pipe, what is another reason for a water leak?
7. How many different ways of locating leaking pipes are there?
8. At least how many people are necessary to complete the peppermint test?
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