Precedent Study

1. Precedent Study Tyler Gentry

2. Items of Study • Water tower • Sump Pump • Vacuum

3. Water Tower • A big reason for that level of reliability is the water tower. You see water towers everywhere, especially if you live in a flat area full of small towns. Each water system has one or more towers. In this article, we will look at how water towers work. The next time you drive by a water tower, you will know exactly what it is doing. • Tower, Tank and PumpA water tower is an incredibly simple device. Although water towers come in all shapes and sizes, they all do the same thing: A water tower is simply a large, elevated tank of water. For example, take the water tower shown at the right. This tower is located in Kill Devils Hill, near Kitty Hawk, NC. It is about 165 feet (50 meters) tall. • Water towers are tall to provide pressure. Each foot of height provides 0.43 PSI (pounds per square Inch) of pressure. A typical municipal water supply runs at between 50 and 100 PSI (major appliances require at least 20 to 30 PSI). The water tower must be tall enough to supply that level of pressure to all of the houses and businesses in the area of the tower. So water towers are typically located on high ground, and they are tall enough to provide the necessary pressure. In hilly regions, a tower can sometimes be replaced by a simple tank located on the highest hill in the area. • A water tower's tank is normally quite large. A normal in-ground swimming pool in someone's backyard might hold something like 20,000 or 30,000 gallons (that's a lot of water!), and a typical water tower might hold 50 times that amount! Typically, a water tower's tank is sized to hold about a day's worth of water for the community served by the tower. If the pumps fail (for example, during a power failure), the water tower holds enough water to keep things flowing for about a day.

4. Water Tower Continued • One of the big advantages of a water tower is that it lets a municipality size its pumps for average rather than peak demand. That can save a community a lot of money. • Say that the water consumption for a pumping station averages 500 gallons of water per minute (or 720,000 gallons over the course of a day). There will be times during the day when water consumption is much greater than 500 gallons per minute. For example, in the morning, lots of people wake up at about the same time (say 7:00 a.m.) to go to work. They go to the bathroom, take a shower, brush their teeth, etc. Water demand might peak at 2,000 gallons per minute at 7 a.m. -- there is a big cost difference between a 500-gallon-per-minute pump and a 2,000-gallon-per-minute pump. Because of the water tower, the municipality can purchase a 500-gallon-per-minute pump and let the water tower handle the peak demand. At night, when demand normally falls to practically zero, the pump can make up the difference and refill the water tower. • In most towns, the water people drink comes from either a well, a river or a reservoir (normally a local lake). The water is treated in a water treatment plant to remove sediment (by filtration and/or settling) and bacteria (typically with ozone, ultraviolet light and chlorine). The output from the water treatment plant is clear, germ-free water. A high-lift pump pressurizes the water and sends it to the water system's primary feeder pipes. The water tower is attached to the primary feeders quite simply, as shown in this diagram:

5. Water Tower Continued • Another interesting fact about water towers -- they can affect your insurance rates! During a fire, the water demand increases significantly and may greatly exceed the capacity of the pumps at the water plant. A water tower guarantees that there will be enough pressure to keep water flowing through the fire hydrants. Fire insurance rates are normally lower in a community in which the water system has water towers. • The next time you are out driving around, especially if you are driving through a series of small towns, take the time to notice the water towers. Now that you know how they work, you will be amazed by how many you see and by all the different forms they take!

6. Water Tower Facts • For pilots of small, private aircraft, water towers are a huge help because: They are large. • They are elevated, making them easy to see from an airplane. • All small towns have them. • Small towns are nice enough to paint the town's name on nearly every tower! • If you have ever been in a small airplane flying cross-country, you know that from the air, all small towns look the same; it is very easy to get confused. When you don't have a GPS receiver, water towers make navigation a LOT easier!

7. Sump Pumps • A sump pump is a small pump installed in the lowest part of a basement or crawlspace. Its job is to help keep the area under the building dry and to prevent it from flood­ing. Usually, sump pumps are installed in specially constructed sump pits. Water flows into the sump pit through drains or by natural water migration through the soil. The sump pump's job is to pump the water out of the pit and away from the building so the basement or crawlspace stays dry. • According to the American Society of Home Inspectors, more than 60 percent of American homes suffer from below-ground wetness [source: Basement Systems]. But even more homeowners are likely to have to deal with a flooded basement at some point. It doesn't take much water to cause thousands of dollars of damage. A moist basement can also lead to mold and mildew growth, bringing with it all its related health and breathing hazards.

8. Sump Pumps Continued • ­A sump pump usually stands in a sump pit -- a hole with a gravel base about 2 feet (60 centimeters) deep and 18 inches (45 centimeters) wide -- dug in the lowest part of your basement or crawlspace. As the pit fills with water, the pump turns on. It moves the liquid out of the pit through pipes that run away from your home to a spot where the water can drain away from your foundation. The pipe usually has a one-way valve called a check valve at the pump end to keep the water from flowing back into the pit. • Most sump pumps turn on automatically through a float activator arm or a pressure sensor. The pressure sensor works just like its name suggests: Water exerts more pressure on the sensor than air does, which causes the pump to activate. The float activator works a lot like the one in your toilet tank. A buoyant ball floats on top of the water, manually moving the arm as the water level rises. You can also buy a manually operated pump, which works only when you decide to turn it on, but these aren't as common because of their lack of convenience. Automatic pumps also have an option for you to activate the pump if the float arm or sensor should fail to work. • The typical home sump pump uses a centrifugal pump to move water. When the motor is on, it causes a screw- or fanlike device called an impeller to turn. Using centrifugal force, the spinning impeller forces water toward the sides of the pipe, creating a low-pressure area at its center. Water from the pit rushes to fill the void, and the impeller's spinning action pushes it out through the pipe. • Sump pumps for home use are powered by electricity and use standard household current, so they don't require specialized wiring beyond a grounded outlet. Since the pump is always in or near water, it's a good idea to have a ground fault circuit interrupter (GFCI) on the outlet to prevent accidental electrocution. • There are two primary sump pump designs, both of which are about 2 1/2 to 3 feet (76.2 to 91 centimeters) high. A submersible pump rests in the water. It's encased in a waterproof housing, with the pump itself at the bottom and the outlet pipe near the top. A flat screen or grate covers the bottom of the pump to keep out debris. When the pump turns on, water is sucked up through the grate and routed into the pipes and out of your home. • The other common type of sump pump is the pedestal pump. Pedestal pumps look something like a long stick with a fat head. The pedestal keeps the pump out of the pit, away from the water even when the pit is full. An inlet pipe reaches down into the bottom of the pit to draw the water out. Since the motor and pump are out of the water, pedestal pumps are usually louder -- but less expensive -- than submersible pumps. • Read on to learn whether you need one of these pumps in your home and what to do to keep it working once it's installed.

9. Sump Pumps Continued • Most sump pumps are equipped with water level or flood alarms, usually battery powered, that alert you if the pump isn't working properly and water is backing up. More sophisticated systems can notify your alarm company or call your cell phone if the water starts to rise. Fortunately, this shouldn't happen often. Sump pumps on the whole are quite reliable. But as with any other important piece of equipment, regular maintenance is always a good idea. Spend a few minutes every couple of months, when heavy rains are forecast and in early spring to ensure reliable sump pump operation. Basic sump pump maintenance is usually as simple as doing these few jobs.

10. Vacuums • It may look like a complicated machine, but the conventional vacuum cleaner is actually made up of only six essential components: • An intake port, which may include a variety of cleaning accessories • An exhaust port • An electric motor • A fan • A porous bag • A housing that contains all the other components

11. Vacuums Continued

12. Resources • http://www.howstuffworks.com/water.htm • http://home.howstuffworks.com/home-improvement/plumbing/sump-pump.htm/printable • http://home.howstuffworks.com/vacuum-cleaner.htm