Online Store


Wading Area: That area less than 3 feet in depth devoted to activity of non-swimmers.

Wall Slope: The inclination from vertical in a pool wall, expressed in degrees or in feet (or inches) of horizontal distance in a given depth in feet (or inches).

Walls: The interior pool wall surfaces consisting of surfaces from the plumb to a 45° slope.

Wastewater: Water that has been used in homes, industries, and businesses that is not for reuse unless it is treated.

Wastewater-treatment return flow: Water returned to the environment by wastewater-treatment facilities.

Water cycle: The circuit of water movement from the oceans to the atmosphere and to the Earth and return to the atmosphere through various stages or processes such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transportation.

Water Hammer  - Water hammer is the momentary increase in pressure that occurs in a water system when there is a sudden change of direction or velocity of the water and these pressure fluctuations can be severe enough to rupture a water main. This tech brief offers some practical design solutions to this potential problem.

Water hammer (pressure surge)-1-: If in systems with long discharge lines,(e.g. in industrial and municipal water supply systems ,in refineries and power stations) the pumped fluid is accelerated or decelerated, pressure fluctuations occur owing to the changes in velocity. If these velocity changes occur rapidly , they propagate a pressure surge in the piping system, originating from the point of disturbance ; propagation takes place in both directions (direct waves),and these waves are reflected (indirect waves) at points of discontinuity ,e.g. changes of the cross sectional area ,pipe branches, control or isolating valves, pumps or reservoir. The boundary conditions decide whether these reflections cause negative or positive surges. The summation of all direct and indirect waves at a given point at a given time produces the conditions present at this point. These pressure surges, in addition to the normal working pressure ,can lead to excessive pressure and stresses in components of the installation . In severe cases such pressure surges may lead to failure of pipe work, of fittings or of the pump casings. The minimum pressure surge may, particularly at the highest point of the installation ,reach the vapor pressure of the pumped liquid and cause vaporization leading to separation of the liquid column. The ensuing pressure increase and collision of the separated liquid column can lead to considerable water hammer .The pressure surges occurring under these conditions can also lead to the failure or collapse of components in the installation.

Water hammer-2-: Occurs in a closed piping system as a result of the pressure being rapidly increased when the liquid velocity is suddenly increased. This damaging effect is usually the result of sudden starting, stopping, change in pump speed, or the sudden opening or closing of a valve. Water hammer can usually be controlled by regulating the valve closure time, surge chambers, relief valves or other means.

Water Hammer-3-: The shock wave or series of waves caused by the resistance of inertia to an abrupt change of water flow through a water piping system. Water hammer may produce an instantaneous pressure many times greater than the normal pressure. For this reason, many building codes now require the installation of a "water hammer arrestor" or accumulation device to absorb shock waves and prevent damage to appliances such as washing machines as well as water treatment components such as reverse osmosis membranes.

Water Hammer-4-: Water Hammer is energy transmitted back to the pump due to the sudden stoppage of water flowing from the pump. Water hammer is more likely to occur when using a very long discharge hose. If the flow of water at the end of the discharge hose is shut off in less than the "critical time", energy is transmitted back to the pump causing a large pressure spike in the pump housing. Water hammer often results in damage to the pump casing.

Water Horse Power (W.H.P.): The calculated horse power coming out of the pump using the formula WHP = head x gpm/3960

Water Horsepower-1-: The energy added by the spinning impeller.

Water Line: Overflow System: The water line shall be at the top of the overflow rim.

Water Line-1-: Skimmer System: The water line shall be at the midpoint of the operating range of the skimmers.

Water quality: A term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose.

Water Slinger: A rubber or plastic washer installed on motor shaft to prevent water from entering the motor from seal leakage.

Water Softener: A pressurized water treatment device in which hard water is passed through a bed of cation exchange media for the purpose of exchanging calcium and magnesium ions for sodium or potassium ions, thus producing a "softened" water which is more desirable for laundering, bathing and dish washing. This cation exchange process was originally called zeolite water softening or the Permutit Process. Most modern water softeners use a sulfonated bead form of styrene/divinylbenzene (DVB) cation resin.

Water table: the top of the water surface in the saturated part of an aquifer.

Water Table-1-: The upper level of the saturated zone. This level varies greatly in different parts of the country and also varies seasonally depending on the amount of rain and snowmelt.

Water use: Water that is used for a specific purpose, such as for domestic use, irrigation, or industrial processing. Water use pertains to human's interaction with and influence on the hydrologic cycle, and includes elements, such as water withdrawal from surface- and ground-water sources, water delivery to homes and businesses, consumptive use of water, water released from wastewater-treatment plants, water returned to the environment, and instream uses, such as using water to produce hydroelectric power.

Water wells: Generally classified according to the method used to create or construct the well. The four most common types are dug wells, bored wells, driven wells and drilled wells.

Water: A very common organic solvent that weighs 8.334 pounds per gallon when fresh.

Water-Logged Pressure Tank: A condition in an air over water tank where the trapped air volume required for most efficient pump operation has leaked out of the tank, which will cause pump motor burnout. Symptoms are the pump runs in very short bursts and turns on and off frequently; the pump runs every time a faucet is opened; water pressure surges while the shower or a faucet is running; pump runs all the time but the water pressure is low. Waterlogging is a symptom of a ruptured or leaking air bladder.

Watershed: The land area that catches rain or snow and drains it into a local water body (such as a river, stream, lake, marsh, or aquifer) and affects its flow, and the local water level. Also called a recharge area.

Watershed-1-: The land area that drains water to a particular stream, river, or lake. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large watersheds, like the Mississippi River basin contain thousands of smaller watersheds.

Watt: A measure of power. 746 watts equals one horsepower.

Watt-1-: The amount of power required to maintain a current of one ampere at a pressure of one volt. Most motors are rated in Kwatt equal to 1,000 watts. One horsepower is equal to 746 watts.

Watt-1-: A unit of measurement that indicates the amount of electrical power in a circuit.

Watt-hour (Wh): An electrical energy unit of measure equal to one watt of power supplied to, or taken from, an electrical circuit steadily for one hour.

Wattmeter: instrument designed to measure load, in Watts (or Kilowatts).

Watts: A measurement of electrical power where watts = volts x amps. One watt is the rate of energy expended when a steady current of one amp flows under a pressure of one volt. 1HP = 746 Watts. Also known as Joules per second

Weak wells: A weak well application occurs when the pump lowers the water level in the well faster than the well can replenish itself. A deep well jet pump with a tail pipe is particularly effective when flow requirements are relatively small. By adding 35 feet of tail pipe below the jet assembly with a foot valve attached at the bottom, it will not be possible to pull the well down and allow air to enter the system.

Wear Plate: A replaceable steel insert that fits inside the voluyte or suction cover of a pump. Helps to form a vacuum with the impeller and reduce the cost of replacement parts.

Wear ring: Used with closed impeller pumps to restrict leakage from the high-pressure side of the pump to the low- pressure side. Should be replaced when the recommended clearance is doubled.

Weir: The device in a skimmer that controls the amount of water coming into the skimmer, and keeps debris inside.

Welded metal bellows: A seal design used to eliminate the use of elastomers. Excellent for cryogenic and hot applications. Not as effective for hot petroleum applications because of "coking" problems

Well (deep): A well with a static (standing) water level greater than 25'.

Well (shallow): A well with a static (standing) water level of 25' or less.

Well (water): An artificial excavation put down by any method for the purposes of withdrawing water from the underground aquifers. A bored, drilled, or driven shaft, or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil, or to store or bury fluids below ground.

Well Cap: A tight-fitting, vermin-proof seal designed to prevent contaminants from flowing down inside of the well casing.

Well casing: A steel or plastic pipe inserted into a drilled well to prevent dirt and debris from contaminating the water.

Well Casing-1-: The tubular lining of a well. Also a steel or plastic pipe installed during construction to prevent collapse of the well hole.

Well size: The inside diameter of the well.

Wellhead Protection Area: The area surrounding a drinking water well or well field which is protected to prevent contamination of the well(s).

Wellhead: The top of a structure built over a well. Term also used for the source of a well or stream.

Wet Battery (cell): An electrochemical cell or battery in which the electrolyte is in the liquid form.

Wet end: The part of the pump that gets wet from the pumping fluid. Includes the volute, stuffing box, impeller wear rings, and shaft or sleeve.

Wet Niche: A watertight and water cooled unit submerged and placed in a niche in the pool wall.

Wet-Rotor (Hysteresis) Pumps: The wet-rotor pumps, often mistaken as magnetic drive pumps, utilize an epoxy-encapsulated motor and plastic housing. A permanent magnet is attached to the impeller. The magnet acts as the rotor would in a conventional motor. The water being pumped surrounds the rotor, thus the term "wet-rotor". They are seal-less and oil-less. These pumps work well in water garden, statuary, and some industrial applications. They are the most compact and energy efficient type of pump manufactured. The other side of this efficiency is very little starting torque. therefore, these pumps do not produce as much pressure and will not pump water as high as as their epoxy-encapsulated counterparts.

Wet-Rotor (Hysteresis): Often referred to as magnetic drive pumps, utilize an epoxy-encapsulated motor and plastic housing. A permanent magnet is attached to the impeller. The magnet acts as the rotor in a conventional motor. They are seal-less and oil-less.

White Wire: only hooked to the neutral bar and would tell an electrician that the wire was safe to touch.

Williams and Hazen Head Loss Tables: are based on the head loss in ten-year old pipe.

Winterizing: In areas where the ground freezes, pipes have to be drained and sometimes "blown out" with pressure air.

Wiring Diagram: shows how the pump is wired for voltage.

Withdrawal: Water removed from a ground- or surface-water source for use.

Work: The amount of energy expended to move something times the distance the object is moved.

Work-1-: the energy required to drive the fluid through the system.

Wye-Delta Starting: A method for starting a motor at rated voltage but drawing locked rotor current and producing reduced locked rotor torque to provide lower starting torque than a straight delta connection. Once the load and motor have been started, the wiring will switch from the wye connection to a delta connection in which mode it must run and deliver full torque.