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Wells & Pumps

Well types

In many areas of the country, finding potable water is as easy as getting out a shovel and digging a hole in the ground. Okay, maybe "easy" isn't the right word, but wherever the water table is only several feet below the surface of the ground, part of the battle may already be over. In such a shallow-well situation, lifting the water up to the house is going to be a little easier, if only because the distance you have to move it is modest.

If your area doesn't have a high water table, or if it lacks a stable supply of potable water near the surface, you must dig deeper to achieve the same result. And because a deep well means that the water has to be lifted farther, the strategies for moving it change.

Shallow-well pumps

These days, the most common pump for a shallow well is a jet pump. Jet pumps are mounted above the well, either in the home or in a well house, and draw the water up from the well through suction (see Single-Drop Jet-Pump System diagram on next page). Because suction is involved, atmospheric pressure is what's really doing the work. Think of the system as a long straw. As you suck on the straw, you create a vacuum in the straw above the water. Once the vacuum is there, the weight of the air, or atmospheric pressure, pushes the water up the straw. Consequently, the height that you can lift the water with a shallow-well jet pump relates to the weight of the air. While air pressure varies with elevation, it's common to limit the depth of a jet-pump-operated shallow well to about 25 ft.

Jet pumps create suction in a rather novel way. The pump is powered by an electric motor that drives an impeller, or centrifugal pump. The impeller moves water, called drive water, from the well through a narrow orifice, or jet, mounted in the housing in front of the impeller. This constriction at the jet causes the speed of the moving water to increase, much like the nozzle on a garden hose. As the water leaves the jet, a partial vacuum is created that sucks additional water from the well. Directly behind the jet is a Venturi tube that increases in diameter. Its function is to slow down the water and increase the pressure. The pumped water–new water that's drawn from the well by the suction at the jet–then combines with the drive water to discharge into the plumbing system at high pressure.

Because shallow-well jet pumps use water to draw water, they generally need to be primed–filled with water–before they'll work. To keep water in the pump and plumbing system from flowing back down into the well, a 1-way check valve is installed in the feed line to the pump.

Shallow-well pumps

These days, the most common pump for a shallow well is a jet pump. Jet pumps are mounted above the well, either in the home or in a well house, and draw the water up from the well through suction (see Single-Drop Jet-Pump System diagram on next page). Because suction is involved, atmospheric pressure is what's really doing the work. Think of the system as a long straw. As you suck on the straw, you create a vacuum in the straw above the water. Once the vacuum is there, the weight of the air, or atmospheric pressure, pushes the water up the straw. Consequently, the height that you can lift the water with a shallow-well jet pump relates to the weight of the air. While air pressure varies with elevation, it's common to limit the depth of a jet-pump-operated shallow well to about 25 ft.

Jet pumps create suction in a rather novel way. The pump is powered by an electric motor that drives an impeller, or centrifugal pump. The impeller moves water, called drive water, from the well through a narrow orifice, or jet, mounted in the housing in front of the impeller. This constriction at the jet causes the speed of the moving water to increase, much like the nozzle on a garden hose. As the water leaves the jet, a partial vacuum is created that sucks additional water from the well. Directly behind the jet is a Venturi tube that increases in diameter. Its function is to slow down the water and increase the pressure. The pumped water–new water that's drawn from the well by the suction at the jet–then combines with the drive water to discharge into the plumbing system at high pressure.

Because shallow-well jet pumps use water to draw water, they generally need to be primed–filled with water–before they'll work. To keep water in the pump and plumbing system from flowing back down into the well, a 1-way check valve is installed in the feed line to the pump.

Breaking the depth barrier

Unfortunately, you may have to go a little deeper than 25 ft. for your water. Surprisingly, you can still do it with a jet pump. It simply involves separating the jet from the motor and impeller housing and placing the jet assembly down in the water (see Double-Drop Jet-Pump System diagram). In a typical deep-well jet-pump configuration, one pipe mounted to the impeller housing drives water down into the jet body that's located about 10 to 20 ft. below the minimum well water level. A second pipe connects the output side of the jet body back to the pump.

At the jet, the increase in water velocity creates the partial vacuum that draws standing well water into the second pipe and then back into the pump and plumbing system. Deep-well jet pumps use both the suction at the jet to bring water into the system and pressure applied by the impeller to lift the water.

To prevent overpumping the well, a deep-well jet-pump installation may include a 35-ft.-long tailpipe. It's connected to the intake end of the jet housing and extends down into the well. If the water level dips below the level of the jet housing, the pump operates in the same manner that a shallow-well pump does. While flow rate drops off, water will be available until the level drops below about 25 ft. from the jet housing-the limit for a shallow pump. The 35-ft.-long tailpipe effectively ensures that the well will never be pumped out. Of course, the height of the jet over the water level affects performance. The farther away it is, the less efficient the pumping becomes.

Like shallow-well systems, a jet pump in a deep-well system needs to be primed to operate. A foot valve at the bottom of the well piping prevents water from draining from the pipes and pump. Jet pumps that have two or more impellers are called multistage pumps.

Moving to the source

While a jet pump can reliably handle a well several hundred feet deep, a more effective solution is to move the pump down into the well so, instead of lifting the water, it's pushing it up. A typical submersible pump is characterized by a long cylindrical shape that fits inside the well casing. The bottom half is made up of a sealed pump motor that is connected to the aboveground power source and controlled by wires. The actual pump half of the unit is comprised of a stacked series of impellers-each separated by a diffuser-that drives the water up the pipe to the plumbing system.

In modern installations, the well casing outside the home is connected to the plumbing system by a pipe that runs beneath the ground to the basement (see Submersible Pump System diagram). This horizontal pipe joins the well pipe at a connector called a pitless adapter. The function of the adapter is to permit access to the pump and well piping through the top of the well casing, while routing water from the pump into the plumbing system.

While submersible pumps are more efficient than jet pumps in delivering more water for the same size motor, pump or motor problems will necessitate pulling the unit from the well casing-a job that's best left to a pro. However, submersibles are known for their reliability and often perform their role 20 to 25 years without servicing. Submersible pumps may also be used in shallow wells. However, silt, sand, algae and other contaminants can shorten the pump's life.

Common elements

No matter what kind of system you have, the components on the output side of all pumps are similar.

Pumps are not intended to run continuously, and they don't start each time you open a tap or flush the toilet. In order to provide consistent water pressure at the fixtures, the pump first moves water to a storage tank. Inside a modern tank is an air bladder that becomes compressed as the water is pumped in. The pressure in the tank is what moves the water through the household plumbing system.

When the pressure reaches a preset level, which can be anywhere from 40 to 60 psi, a switch stops the pump. As water is used in the home, pressure begins to decrease until, after a drop of about 20 psi, the switch turns on the pump and the cycle is repeated. You'll find the pressure gauge mounted on the tank with wires leading to the switch that controls the pump.

Goals: For you the customer to save money and Pumpworld to stay in business. Sizing your submersible made easy. Knowledge for the consumer.

 

Why should I buy at Pumpworld??

Pumpworld like other companies is on the Internet to do business and you like other people on the Internet are here to save money and gain knowledge. Pumpworld's main goal is to educate our  customers before we sell a product.  We have listed commonly asked questions in order to make Pumpworld more efficient so when you place your order the lines are not tied up with questions answered here . Please read through it, the basic facts here can not only be applied to submersible pumps but to other water moving mechanical devices. We hope you find it helpful making your purchase a pleasant and satisfying one.

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How do submersible pumps work?

Submersible pumps work on a centrifugal basis. Since a submersible pump sets in the water to operate it's very efficient and it uses the water to cool the motor making it even more efficient. This is why you  see few  wind mills or jet pumps doing the job of submersible pumps. The Diameter of a well is very restrictive to the operation of a centrifugal pump so the impellers have to be stacked in order to produce pressure.  This is why submersible pumps are very long. A standard 4" submersible pump measures anywhere from 24" to 48" long and  3.9" diameter and spins at 3600 rpm. The 3"submersible pumps(2.9") diameter spin at about 8000 rpm. 

Centrifugal pump at work

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How are water flow and pressure related?

In a centrifugal pump water flow and pressure are interchangeable. A submersible pump produces pressure and flow on a centrifugal basis. Pressure is usually stated in PSI (pounds per square inch). Pressure can also be stated as LIFT(as in vertical lift). 1 PSI = 2.31 feet.   For example: When a  submersible pump is turned  on it forces water through a pipe. If the pipe is in a vertical position the pipe will have pressure throughout. the higher the pipe the more pressure the pump needs to fill the pipe. If the pipe is at a horizontal  position the pressure converts to flow and the only pressure being used is the friction the water produces in the pipe. Special note: Pumps always pump from the water level not from the pump setting .

 

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Now that I know how submersible  pumps work how do I get power to the pump when it's in the well? And what is the difference between 2 wire and 3 wire pump units?

Like all electrical appliances pumps require a certain amount of current at a certain amount of voltage(usually 230v, single phase). To ensure the proper amount reaches the pump unit you have to use the proper submersible electric cable(click here to see chart). 3 wire units use what's called 3 wire with ground "flat jacket" , two wire units use 2 wire with ground flat jacket or they can also use 3 wire with ground by eliminating one wire. Submersible pump motors use AC current usually 230v , 1 phase. This means that you have two wires from your fuse box and if you measure the voltage on both wires with a volt meter you get 230 volts. The two wires are routed into the control box and they are known as "L1 and L2"(line 1 and line 2). An AC motor has two sets of windings in the stator(start windings and run windings). The control box controls the windings.  The capacitors in the control box helps start the pump with a kick(this is needed to overcome any pressure that exists in the column pipe). After about a second of time the solid state switch(1-1\2hp to 15hp use a relay) in the control box switches the motor windings from start to run . A two wire motor has no external control box like the three wire units , all of the components of the control box are inside the motor. The price is the same for both types and there is no advantage in performance  other than aesthetics. 2 wire motors range from 1\3 hp to 1-1\2 hp. 3 wire motors range from 1\3 hp to 15 hp single phase respectively.

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Can you give me a quick example of how to calculate my own pump? And what role does the pressure tank play?

Every well is different. Your pump needs to be calculated for your unique well. 5 relative points to consider when sizing your submersible pump. 1 :Pressure desired at the home or at surface. Pressure and vertical lift are the same. PSI or lift is the amount of work the pump needs to move a certain quantity of water through a pipe either vertical or horizontal it takes work . Usually 50psi is enough for most homes. It's enough pressure to shower and run every water appliance in your home. 2 :Pumping level . When there is no activity in well the  level of the water rises to a certain point, this is called " static leve l". When the well is being pumped and the water level drops to a certain point and holds steady this is referred to as " pumping level " . Pumping  level is very important. If the pumping level is unknown you have to guess and if you guess wrong the pump might not be strong enough or it might be to strong for your needs. Try to get this information from your driller. If he can't help ask a neighbor to see what their pumping level is. This might help you. 3 :Elevation difference. You must consider all elevation differences from top of well to home. Vertical lift is the work the pump must perform and it must be considered from all angles. 4 :friction losses. When water moves through rocks or sand or a pipe friction is created. The friction must be calculated. We have a chart on this site for your needs. Usually the size of the pipe used is the same as the discharge of the pump. In the illustration 1-1\4" pipe is used. 1-1\4" is a standard size for residential wells. 5: Water flow: Water flow is the amount of water you need at any given time in your home. When you open a tap it uses 2.5 gpm(gallons per minute). The pump in this illustration produces 18 gpm. You can open 7 taps without exceeding the pump capacity. Some taps use more than others such as an outdoor faucet(uses aprx 10 gpm). A shower head uses 2.5 gpm.  Pressure Tanks: Pressure tanks(80 gallon standard size) store the energy the pump has expanded in the form of pressure. Air is compressed in the top chamber and it is separated from the water by a diaphragm. When you turn on the tap the pressure is releases in the form of water flow. After about 30 or so gallons of flow a device called a pressure switch turns the pump on to rebuild the pressure. As soon as the system builds 50 psi the pump turns off. Again the pressure is stored in the tank until it is needed once more. Note : Modern tanks are referred to as "captive air". This means they need no maintenance , they are pre-charged at the factory with air pressure. Note: Ideal pump setting is usually 20' above the bottom of well(this is not a strict rule just a guide). Your pump setting must be at least 20' past your pumping level or your pump will run dry ruining the pump.

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What type of drop pipe and wire should I use?

You have three choices when it comes to pipe,  if your well is 0 to 300 feet deep. You can use poly or schedule 80 PVC or Galvanized pipe. Poly pipe (for up to 3 hp) has the clear advantage over the other two  because it's easy to install and you usually don't need to hire a boom truck to drop the pump in  the well . Poly pipe also comes in continuous rolls of 100 foot or 300 foot , no couplings to screw on. Poly pipe does not deteriorate in the well.  Schedule 80 PVC  pipe is as light as poly pipe but since it is rigid you need a tri-pod or a boom truck or other pulling device to install. Furthermore the pipe has to be coupled together with either PVC schedule 120 threaded couplings or galvanized couplings or brass couplings. Galvanized pipe is the strongest of the three types but it is susceptible to corrosion(for deep settings you have no choice but to use galvanized because of  it's superior strength). If your well is 300 to 500 feet deep your choices narrow to schedule 80 PVC (up to 3 hp), 5 hp and over use galvanized pipe. Both types can withstand the extra pressures at that depth. If your well is over 500 foot use galvanized pipe. These are general recommendations  but they may vary depending on installer.

Submersible pump cable is made special for wells. It is flat double jacketed and the jackets are extra thick. Since some wells are put together with steel casing the welds on the casing can cut the wire when installing. The extra thick jacket protects the wire. Some times the wire can rub against the casing the jacket helps against premature wear. Since the jackets build up heat you cannot use a standard wire sizing chart , you must use the chart provided here or through Franklin Electric the submersible motor manufacture.

 

Note: You must use safety rope when using plastic drop  pipe in well.  Goulds recommends check valves every 250 foot.

 

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Tools and extras,

1:  1\2" close end wrench. Butane torch, fillips and flathead screw driver, wrench for up to 1-1\4" pipe. Crimper tool for butt splices. Utility knife(be careful not to cut into any electrical cable when peeling back the jacket of the electrical cable).

Pump installation

2:  Remove pump and motor from boxes .Remove cable guard from pump and Attach pump to motor. Pump flange matches perfectly to motor. Spin shaft in order for splined coupling to slide on to shaft. Look for (4) ss nuts , screw on and tighten. Re-attach the cable guard.

3:  Screw on ss barbed male adapter to pump discharge(use TEFLON tape).

4:  SEE ILLUSTRATION Look for a set of heat shrink tubes with butt splices. Peel flat electric(green wire side in order to not cut into the red, yellow or black wires) cable jacket back about 8" then separate the wires and remove about 3\8" PVC covering from wire end in order to attach butt splice. Use a crimper or pressure pliers and tighten . Slide on heat shrink. One on each wire. Wires are colored coated. Follow color code. Slide the yellow wire from motor onto yellow wire from electric cable and crimp(make sure you slide on heat shrinks first). After cables are attached slide heat shrink over butt connector and with a butane torch heat the shrink all the way around from the center out. Torch should be about 8" away in order not to burn wire or shrink tube. After you reach the ends a wax should ooze out. After tubes cool wrap each wire 3 times about 8" long back and forth.

5:  If you are using the poly pipe attach it onto the barbed connector(if 's tight slightly heat the end of the pipe in order to slide on the tubing and it should go on tight). Cut pipe straps and extend roll of pipe on ground. Attach safety rope onto pump hook or holding hole located on discharge of pump.

6:  Install torque arresters(As many as you like but we recommend a min. of 2, one right above pump and the other about 20 foot above the first one. Squeeze the torque arresters from top to bottom in order to achieve the diameter of well casing. ) , they are used for centering pump. Make sure you do not clamp the electric cable or rope with the torque arrester clamps, run electric cable and rope outside of clamps.

7:  Tape the wire and the safety rope with PVC black tape every 5 to 10 feet along total run of the pipe.

8:  Attach your barbed male adapter to pipe connector end(if 's tight slightly heat the end of the pipe in order to slide on the tubing and it should go on tight) and screw on to galvanized nipple. Slide nipple through well seal and screw on galvanized tee (use TEFLON tape on all threads). Pull electric cable through hole in well seal, pull rope through hole in well seal and attach to your tee or any solid object.

9:  Install the pump into well with help of a friend or two. Slide your pump down hole.

10:  Well seal should slide onto to casing and it should hold your pump.

11:  Use galvanized pipe for above ground installations to make your tank connections.

12:  Use a brass tank tee to make your job easier . The tank tee comes with (2) ports 1\4" fpt (for pressure gage and pressure switch to be attached accordingly) and one 3\4" port(for hose bib, faucet) and three 1-1\4" ports for main plumbing hook-up.

13:  Attach electric cable to control box(follow the color codes). Then run your 230 volt power line(L1,L2) to your pressure switch (follow diagram on pressure switch). Then run your power line from pressure switch to control box(attach control box to grounded pole).

****Make sure all connections are grounded. If this is a new well you have to let it run open discharge to remove all trash.****

  • Good luck and remember this is not "rocket science"
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Tools and extras,

1:  1\2" close end wrench. Butane torch, fillips and flathead screw driver, wrench for up to 1-1\4" pipe. Crimper tool for butt splices. Utility knife(be careful not to cut into any electrical cable when peeling back the jacket of the electrical cable).

Pump installation

2:  Remove pump and motor from boxes .Remove cable guard from pump and Attach pump to motor. Pump flange matches perfectly to motor. Spin shaft in order for splined coupling to slide on to shaft. Look for (4) ss nuts , screw on and tighten. Re-attach the cable guard.

3:  Screw on ss barbed male adapter to pump discharge(use TEFLON tape).

4:  SEE ILLUSTRATION Look for a set of heat shrink tubes with butt splices. Peel flat electric(green wire side in order to not cut into the red, yellow or black wires) cable jacket back about 8" then separate the wires and remove about 3\8" PVC covering from wire end in order to attach butt splice. Use a crimper or pressure pliers and tighten . Slide on heat shrink. One on each wire. Wires are colored coated. Follow color code. Slide the yellow wire from motor onto yellow wire from electric cable and crimp(make sure you slide on heat shrinks first). After cables are attached slide heat shrink over butt connector and with a butane torch heat the shrink all the way around from the center out. Torch should be about 8" away in order not to burn wire or shrink tube. After you reach the ends a wax should ooze out. After tubes cool wrap each wire 3 times about 8" long back and forth.

5:  If you are using the poly pipe attach it onto the barbed connector(if 's tight slightly heat the end of the pipe in order to slide on the tubing and it should go on tight). Cut pipe straps and extend roll of pipe on ground. Attach safety rope onto pump hook or holding hole located on discharge of pump.

6:  Install torque arresters(As many as you like but we recommend a min. of 2, one right above pump and the other about 20 foot above the first one. Squeeze the torque arresters from top to bottom in order to achieve the diameter of well casing. ) , they are used for centering pump. Make sure you do not clamp the electric cable or rope with the torque arrester clamps, run electric cable and rope outside of clamps.

7:  Tape the wire and the safety rope with PVC black tape every 5 to 10 feet along total run of the pipe.

8:  Attach your barbed male adapter to pipe connector end(if 's tight slightly heat the end of the pipe in order to slide on the tubing and it should go on tight) and screw on to galvanized nipple. Slide nipple through well seal and screw on galvanized tee (use TEFLON tape on all threads). Pull electric cable through hole in well seal, pull rope through hole in well seal and attach to your tee or any solid object.

9:  Install the pump into well with help of a friend or two. Slide your pump down hole.

10:  Well seal should slide onto to casing and it should hold your pump.

11:  Use galvanized pipe for above ground installations to make your tank connections.

12:  Use a brass tank tee to make your job easier . The tank tee comes with (2) ports 1\4" fpt (for pressure gage and pressure switch to be attached accordingly) and one 3\4" port(for hose bib, faucet) and three 1-1\4" ports for main plumbing hook-up.

13:  Attach electric cable to control box(follow the color codes). Then run your 230 volt power line(L1,L2) to your pressure switch (follow diagram on pressure switch). Then run your power line from pressure switch to control box(attach control box to grounded pole).

****Make sure all connections are grounded. If this is a new well you have to let it run open discharge to remove all trash.****

  • Good luck and remember this is not "rocket science"

 

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