JET PUMP INSTALLATIONS

Jet pump installations pertain to both single-pipe and two-pipe jet pumps.

You may deal with both new installations and replacements. Previous sections examined different elements of jet pumps. By now you know the basics about the types of equipment used in the installation of jet pumps, as well as having some familiarity with the procedures involved. This section considers a new installation from start to finish, then takes a look at replacement work.

Section 2 described the types of pumps you can choose from for a well system. The sizing requirements were also discussed. Refer to Section 2 for this type of information, although this section supplies a little of fit as a refresher course. For information on selecting and sizing pressure tanks, see Section 4.

Tbl. 1 and 2 list some of the common water requirements for plumbing systems.

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Tbl. 1 Approximate Water Supply Requirements

Home Fixtures Filling Ordinary Lavatory - 2 gal.

Filling avg, Bath Tub - 30 gal.

Flushing Water Closet - 6 gal.

Each Shower Bath - Up to 60 gal, Dishwashing Machine - 15 gal./load Automatic Laundry Machine - Up to 50 gal./load Backwashing Domestic Water Softener - Up to 100 gal.

Yard Fixtures:

½-inch Hose with Nozzle - 3 gpm

¼-inch Hose with Nozzle - 5 gpm

Lawn Sprinkler - 2 gpm

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Tbl. 2 Seven-Minute Peak Demand Period Usage

Performance Rating in Gallons per Minute Pump Discharge Pressure Total Suction Lift 20 PSI 30 PSI Max. Shut-Off in Lbs.

5 feet 8 GPM 6 GPM 51 lbs.

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Fgr. 1 shows the rate of water low needed when both a shower and a kitchen faucet are delivering water at the same time.

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Shower in use same time as kitchen sink faucet on.

2 continuous uses require 6 GPM minimum The capacity required of the pump is determined by the number of continuous use outlets in use at the same time. You can't use water at one or a number of outlets any faster than the pump supplies fit.

Fgr. 1 Two Continuous Uses That Require 6-GPM Water Flow

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See the example provided for an example of the math necessary to compute the discharge demand on a pump.

Fgr. 2 provides an example of how to determine the suction lift of a jet pump.

Fgr. 2 Example of Determining Suction Lift of a Jet Pump

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23' 20' Piping kitchen sink to shower head equivalent length 20' Static water level, pump not running Pumping water level, pump not running Piping pump tank to kitchen sink, equivalent length 30' 10' 30' Fgr. 3 Representative Example of How a Shallow-Well Jet Pump Might Look

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Seven Minute Peak Demand Period Usage Outlets Flow Rate GPM Total Usage Gallons Bathrooms In Home 1 1½ 2-2½ 3-4 Shower or Bath Tub 5 35 53 70 Lavatory 4 2 2468 Toilet 4 5 10 15 20 Kitchen Sink 5 3 3333 Automatic Washer 5 35 - 18 Dishwasher 2 14 --33 Normal seven minute*peak demand (gallons) 45 70 98 122 Minimum sized pump required to meet peak demand without supplemental supply 7 GPM (420) 10 GPM (600) 14 GPM (840) 17 GPM (1020) Note: Values given are average and don’t include higher or lower extremes.

Peak demand can occur several times during morning and evening hours.

Additional Requirements: Farm, irrigation and sprinkling requirements are not shown. These values must be added to the peak demand figures if usage will occur during normal demand periods.

Tbl. 3 Seven-Minute Peak Demand Period Usage

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Install Check Valve Here Or Foot Valve at End of Suction Pipe Nozzle Venturi Fgr. 4 Detail of a Shallow-Well Jet Pump

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NEW INSTALLATION OF A SHALLOW-WELL JET PUMP

Once you have all your sizing facts and figures together, fit is time to install a new shallow-well jet pump. We will assume that the well in question has a depth of about 30 feet. In this case you will be using PE piping for the drop pipe and the water service. The well is in place and the trench is open and allows for the installation of the water service below the local frost line.

Start your job by locating and setting the well pressure tank. Section 4 detailed the procedure for this task. The installation of the pump is taking place in the basement of a home. Fgr. 3 is a representative example of how this installation might look when fit is complete.

After the pressure tank is set in place, you can put the pump in place as well. You might be using a pressure tank with a pump bracket that will hold the pump. Otherwise, you are likely to use a stand-model tank.

Once the pump is in place you can add the components on the pump, including the pressure switch that operates fit. Review Section 6 if you need help remembering the types of components that are used.

Install a full-open valve on the piping that runs from the pump to the pressure tank. The more elements of the system that you can isolate, the easier fit will be for service technicians to work on or replace the pump or pressure tank.

Fgr. 4 shows a close-up detail of a shallow-well jet pump.

It’s advisable to install a full-open valve on the well pump before the water service is connected to the pump. You can use brass male and female adapters to make the transition for the valve to the PE piping. I recommend using metallic fittings for all joints in PE pipe. Remember that fit is recommended that you install two stainless steel clamps to secure PE piping to each barb of a fitting.

Your water service piping may leave the home by being installed below the foundation footing. If the water service was not run into the home prior to the concrete floor being poured, this won’t be possible.

The alternative is to go through the foundation. This may mean making a hole in either a concrete wall or a cinder block wall. The construction crew that formed and poured the walls should have installed a sleeve in the forms that would allow the concrete to low around fit, leaving a gap to give you unrestricted access to the water service trench.

A sleeve that is twice the diameter of the water service is required when penetrating a masonry wall. Sleeves are usually made of Schedule-40 PVC or ABS pipe. Once you have all the connections made, you will need to ill the annular space between the water service pipe and the sleeve. Many installers do this with expanding foam that is sprayed into the sleeve. Then a waterproof sealant is used on both the interior and the exterior faces of the wall. Don’t seal the sleeve until all the connections have been made and tested. If you have to remove the piping for one reason or another, you won’t want fit held in place with expanding foam.

Make sure that the bottom of the trench is compacted and free of debris and sharp objects such as rocks. The water service runs from the valve at the pump to the interior of the well casing. This hole also needs to be sealed with some form of waterproof material.

The next step is to install the drop pipe and the foot valve. Once you know how long you want your well drop to be, you can cut a section of pipe and make fit up with a foot valve on one end of fit and a brass elbow on the other end. This elbow will be used to connect the drop pipe to the water service.

The discharge pipe from a pressure tank should be equipped with a full-open valve. You should also check the air charge in the pressure tank to make sure fit is within a usable range. The home's water distribution piping will begin at the valve on the discharge side of the pressure tank.

That is how you install a jet pump. Once all your well system components are in place and the electrical wiring is done, you can conduct a pressure test to make sure the system works properly. When you are sure that all is as fit should be, seal the pipe sleeves, and you are done.

REPLACING A SHALLOW-WELL JET PUMP

If you know how to install a water pump, replacing one is not much of a challenge. Section 12 provides you with a host of troubleshooting techniques and information that will allow you to determine when a pump should be replaced. Here we will focus on the work required to make a successful replacement.

Once you have determined that a pump must be replaced, the logical starting point is choosing a new pump that is rated for the same performance as the existing pump. This, of course, assumes that a proper pump was installed in the first place.

Your work should begin by turning off the electrical power to the old pump. The next step is closing valves to isolate the pump from the water service and pressure tank. If an installer did not provide these valves, you should drain the pressure tank before you attempt to remove the pump.

Go ahead and remove the old pump. A new pump should fit in the same location. Piping connections may not be the same, but they are easy enough to modify. Once you have the pump in place and piped into the system, you need to decide whether you will reuse the old pump components or install new components. Some customers will want to save money by reusing parts such as a pressure gauge, relief valve, and pres sure switch. This is not a good idea. You are responsible for the installation. If the old parts fail quickly after you have finished the job, you will probably have to replace them under warranty, without being paid for your time. I would insist on using all new components. Most reasonable people will accept this decision.

After all of the connections are made, you can open valves or close the drain valve on the pressure tank, turn on the electrical power, and test your installation. Once you are satisfied that the well system is working properly, you should open a plumbing faucet in a bathtub to remove any air that was trapped in the piping while fit was cut apart. If you decide to purge the air through a kitchen faucet, remove the aerator before you turn the water on. The screen in the aerator could become clogged with debris if you leave fit in place during the purging process. Replace the aerator once the system is running properly, and go back and check the well system connections again. If they are still solid, you should be done.

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Pressure Control Valve (AV22) Suction Pipe Venturi Twin Pipe Deep Well Jet Assembly Foot Valve Nozzle Pressure Pipe

Fgr. 5 Detail of a Deep-Well Jet Pump

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Jet Pumps Typical Installations SHALLOW WELL SYSTEM 2-PIPE PITLESS ADAPTER OVER THE WELL OFFSET ADAPTER TWIN PIPE DEEP WELL SYSTEM PACKER DEEP WELL SYSTEM Typical Jet Pump Installations Fgr. 6 Typical Installations of Various Types of Jet Pumps

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INSTALLATION OF A DEEP-WELL JET PUMP

The installation of a deep-well jet pump is very similar to that of a shallow well pump. Therefore, we will only cover the differences in this section.

Take notice of Fgr. 5 for a detailed view of a deep-well jet pump.

Fgr. 6 illustrates typical installations of various types of jet pumps.

Shallow-well jet pumps use only a single pipe in the well installation.

That pipe is a suction pipe. However, deep-well jet pumps use two pipes to enter the well. One of the pipes is a pressure pipe and the other one is a suction pipe. Due to the low lift required for a shallow-well jet pump, fit can operate with only suction power. Deep wells require a jet pump that pushes water down one pipe and pulls fit up the other pipe to compensate for the added depth.

When the pipes from a deep-well jet pump reach a wellhead, they are typically installed either in through the top of the well cap or with the use of two pitless adapters that are installed in the side of the well casing. The use of pitless adapters is the more common of the two installations. As the pipes extend into the well, they are fitted with a twin-pipe jet assembly.

The actual installation of the jet assembly and foot valve is done before the piping is lowered into a well. A foot valve is then attached to the jet assembly. In the case of a well with a low recovery rate, a section of tail pipe is installed between the jet assembly and the foot valve. This lowers the foot valve to compensate for the poor recovery rate of the well to pre vent the well from being pumped below the level of the foot valve. (We discussed this in Section 3.) Aside from the use of two pipes rather than one, the installation procedure is essentially the same for both shallow-well jet pumps and deep well jet pumps. This is also true for the replacement of a two-pipe pump.