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WATER PUMP REPAIR GUIDE
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WATER PUMP SHORT CYCLING
WATER SOFTENERS & CONDITIONERS
WATER TANK REPAIR PROCEDURES
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL CHLORINATION & DISINFECTION
WELL FLOW RATE
WELL WATER PRESSURE DIAGNOSIS
WELL YIELD IMPROVEMENT
WINTERIZE A BUILDING
Guide to 2-line jet pumps on water wells: this article describes the components of a two-line jet pump water system, what the components look like, and what they do. We discuss how two-line jet pumps are selected, installed, jet pump troubleshooting, & repair procedures.
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Refer to the illustration at above right, courtesy of Carson Dunlop and also to our rough sketch provided below to see the components providing well water to a building served by a two-line jet pump located apart from the well.
In our drawing the two line jet pump which draws water from the well and the water pressure tank are shown located separately from the well itself, and the well and its casing are shown located inside of a well pit.
Well pits such as the one we've drawn are used especially in climates exposed to freezing weather, as a way to get access to the well casing and well piping and to route well piping out of the well through the top of the well casing and on to the building while protecting it from freezing.
In addition to showing a well pit in this sketch, we discuss and illustrate well pits a bit more at Well Pits
A more modern device, the pitless adapter which permits a water tight piping connection out through the side of the well casing is shown in our sketch at Components of a Drilled Well with a Submersible Water Pump.
A two-line jet pump can typically raise water from depths of 30-feet to 80-feet, and at water delivery rates of 4 gpm (gallons per minute) (for a 1/2 hp 2-line jet pump serving an 80 foot deep well) to 16 gpm (for a 1 hp 2-line jet pump serving a 30 foot deep well). At WATER PUMP CAPACITIES TYPES RATES GPM we compare the pumping capacities of one line jet pumps, two line jet pumps, submersible well pumps, and other water pumping methods.
A nice example table of Deep Well 2-Line Jet Pump Capacities for 1/2 hp and 1 hp deep well pumps is provided in the Water Ace Jet Pump Installation Manual and excerpted below to illustrate the factors that determine well pump capacity. Both of the charts below are for 2-line jet pumps produced by Water Ace. 2-Line jet pumps intended for deep well use and made by other manufacturers can be expected to have similar capacities.
The Water Ace charts (shown in part above) make clear that the capacity of a deep well pump to deliver water at a given flow rate varies by these factors:
Permission requested, Water Ace Corp. Aug 2010 - Pentair Pump Group.
Watch out: Safety warnings are throughout any pump manufacturer's instructions. Because some pump models are capable of developing internal pressures of more than 100 psi, if your building piping, pressure relief valves, safety controls, wiring, and plumbing are not properly installed, very dangerous conditions including electrical shock, tank explosion, and leaks or floods can occur.
A two line jet pump refers to the observation that two pipes are connected between the jet pump and the well. In our photo at left you can see the two black plastic lines leaving the front of the water pump.
A two line jet pump draws water out of the well by magic: it forces water away from the pump and into the bottom of the well through one of the pipes (usually the smaller diameter pipe).
At the bottom of the well water from the jet pump is forced through a venturi device (a sort of funnel shaped opening) and then back upwards into the larger diameter pipe. Water flowing through the venturi device at the bottom of the well piping draws still additional water out of the well and into the larger diameter pipe that flows back to the building.
The requirement to have some water to send down to the well in order to bring a larger quantity of water back is why a two line jet pump can't provide any water or water pressure in a building if it loses its prime. See WELL PUMP PRIMING PROCEDURE if you need to re-prime your jet pump.
In our sketch above see the two arrows showing water entering the bottom of the piping.
The following list and definition of two-line deep well jet pump and water well parts and terms is organized from the top of the drawing towards its bottom and uses names that correspond to those shown in our ugly sketch above.
What is the Well Piping Foot Valve used in a well and what goes wrong with foot valves?
If you keep losing prime at the water pump where a two-line jet pump is installed, it's probable that a check valve at the pump or more likely at the FOOT VALVE in the bottom of the well needs to be replaced.
See WELL PIPING FOOT VALVES for details about this component.
Carson Dunlop's sketch at left shows how a foot valve works and where it is installed. Replacing a foot valve in the well requires that the well be opened and the well piping be pulled out to permit removal of the old valve and installation of a new one.
After replacing the foot valve you should shock the well since you've probably contaminated it by laying your well piping and parts on the ground (and foot valves at the plumbing supplier are not kept in sterile containers).
Some of the well pump troubleshooting suggestions in this list can be found at the Betta-Flo Jet Pump Installation Manualfrom the National Pump Co.
This article series describes various types of drinking water sources like wells, cisterns, dug wells, drilled wells, artesian wells and well and water pump equipment. We provide advice about what to do when things go wrong.
Readers of this document should also see our other diagnostic guides for water pumps, wells, motors, in table form:
Green link shows where you are in this article series.
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