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WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER CONSERVATION MEASURES
WATER CONTAMINANT LEVELS
WATER HAMMER NOISE DIAGNOSE & CURE
WATER ODORS, CAUSE CURE
WATER PUMP REPAIR GUIDE
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
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
Well Tailpipes or Tailpieces serve as Low Water Protection Devices: This article describes the use of a tailpipe or tail piece, or other low water cutoff controls to protect a well pump from damage in a low-recovery rate well, thus extending the life expectancy of water pumps and pump controls.
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How do we protect the well pump from damage if the well is subject to seasonal or permanent low flow rates or has a poor recovery rate? Here we explain the function & role of a tailpiece installed at the bottom of well piping in order to protect the pump and other water supply equipment controls from damage.
Low Well Water well pipe tailpieces or well tailpipes to protect the well pump
When the well pump's capacity is known to exceed the flow rate of the well, a tail pipe, tail piece, or low water cutoff control is installed to protect the pump from damage such as that caused by well pump cavitation or motor overheating.
Details: some wells that are known to have intermittent low water problems may be equipped with a special tailpiece on the water pick-up end of the well pipe precisely to prevent the well pump from becoming damaged when water level in the well drops too low. The red component in our sketch (left) is the ejector used by a two-line jet pump to bring water from the bottom of the well. This red component shows where a well flow protection tailpiece may be added - as an extension below.
A longer taipiece (blue in our sketch) extending into well water (30 inches recommended by the Alberta Canadia DOA) may help avoid air intrusion, but in addition, a special fitting at the in-water end of the tailpiece can cause water to recirculate through a well pump if well water level becomes too low. If the well pump is a submersible model (recommended for well depths over 80 feet), a similar low well water protection device may be installed in the well. In our sketch at left the foot valve is shown in yellow.
The well piping tailpiece (also shown in this sketch) permits the in-well water pump to continue to run by recirculating well water within the pump but by halting delivery of water or slowing delivery of water to the building.
Many sources, including the Penn State School of Forest Resources recommend installing a low water cutoff device to protect a well pump that has to operate in an inadequate or low-yield well. That resource describes an electrical low-water cutoff switch:
A low water sensing device to protect a well pump may be installed in an intermediate water storage tank, for example.
A different approach to water pump protection where the well yield is poor is a tailpiece that is installed in the well itself. When the water level inside a well drops too low, the tailpiece re circulates water through the well pump (keeping the pump cool and protecting it from damage) until the well has recovered and the water level has risen.
Watch out: the low water cutoff devices that we discuss here are intended for building water supply piping to prevent well pump damage. These low water cutoff devices or switches are distinct from and have nothing to do with the heating or steam boiler low water cutoff safety devices discussed at LOW WATER CUTOFF VALVES
Water Pressure Regulation to Protect the Well Pump
A still different approach that may provide some water pump protection by reducing the well pump cycling rate is the installation of a Smart Tank that regulates water flow in the building. According to the manufacturer, Flexcon Industries,
Well pump cavitation describes the entry of air or gases into the mechanical parts that are trying to move water through a water pump. The presence of air or other gases in the actual pump chambers or around the water pump impellers leads to overheating of these parts and mechanical damage to the pump moving parts.
Cavitation can also cause the pump to have to work longer to satisfy the water demand and thus its electric motor to overheat, also reducing motor life.
Cavitation inside of a water pump can be caused by several problems including:
See WATER PUMPS & TANKS for a discussion of common failures and repairs on water pumps and water tanks.
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