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.
WATER HAMMER
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 LINE
The water line shall be defined in one of the following ways:
WATER LINE - OVERFLOW SYSTEM
The water line shall be at the top of the overflow rim.
WATER LINE - SKIMMER SYSTEM
The water line shall be at the midpoint of the operating range of the skimmers.
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.
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.
WET NICHE
A watertight and water cooled unit submerged and placed in a niche in the pool wall.