|
The following list of definitions used by the pool and spa industry is excerpted from ANSI/NSPI standards and reprinted courtesy of the Association of Pool & Spa Professionals.
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W -
X - Y - Z
ACCESSIBLE – Designed to include physically challenged users.
ACID – A liquid or dry chemical used to lower the pH and/or alkalinity of pool or spa water.
ACIDIC –Having a pH below 7.0 Opposite of basic.
ACID WASH – A procedure using an acid solution to clean an interior surface of a pool with subsequent neutralization of the acid.
ACRYLIC – A thermoplastic material that can be extruded, injection-molded or vacuum-formed into usable shapes and surfaces.
ACTIVATED CARBON – A charcoal-like material used to remove colors, odors and/or excess oxidizer from water.
AF – Abbreviation for the alkalinity factor in calculating the saturation index of water.
AGGRESSIVE WATER – Water that is corrosive because it is low in pH and/or calcium hardness and/or total alkalinity.
AIR BLOWER – A device that produces a continuous flow of air.
AIR CONTROL – A means for spa and hot tubs to regulate air flow in the air induction system, thereby increasing or decreasing hydrotherapy action.
AIR SWITCH SYSTEM – An isolated device that sends a pulse of air down a tube to remotely operate electrical equipment.
ALGAE – Microscopic plantlike organisms that contain chlorophyll.
ALGAECIDE (also spelled ALGICIDE) – Any chemical or material that kills algae.
ALGICIDAL – Capable of killing algae.
ALGISTAT – Any substance or agent that inhibits the growth of algae.
ALGISTATIC – Able to inhibit the growth of algae.
ALKALI – A term applied to bases, usually carbonates and hydroxides, which raise the pH and alkalinity when added to water.
ALKALINE – Having a pH above 7.0.
ALKALINITY – A measure of the pH buffering capacity of water, generally expressed in terms of the equivalent concentration of calcium carbonate in milligrams per liter (or ppm).
ALUM (aluminum sulfates) – A compound used to cause suspended solids in water to form filterable masses (flocculate).
AMMONIA - A chemical compound of hydrogen and nitrogen that combines with free chlorine in pools to form chloramines, or combined chlorine. Also combines with free bromine to form bromines.
AMPHOTERIC – Having the ability to serve as either an acid or base.
ANALOG METER – A testing device in which a needle is used to indicate readings on the dial face.
ANTIVORTEX DRAIN COVER (ANTIVORTEX PLATE OR COVER) – A plate or cover that is affixed to the main outlet of a swimming pool or spa to prevent a vortex from forming as water passes through to the main outlet.
AVAILABLE CHLORINE – A rating of a chemicals total chlorine content, based on a comparison to elemental (gaseous) chlorine having 100 percent available chlorine.
BACK PRESSURE – Resistance to flow normally expressed in pounds per square inch (Kilograms per square centimeter).
BACTERIA – Single-celled microorganisms of various forms, some oh which cause infections or disease.
BACTERICIDE – Any chemical that kills bacteria.
BACKWASH – The process of cleansing the filter medium and/or elements by the reverse flow of water through the filter.
BACKWASH CYCLE - The time required to backwash the filter medium and/or elements and to remove debris in the filter vessel.
BACKWASH RATE – The rate of flow water through the filter medium per unit of area (U.S. gallons per minute per square foot).
BALANCE – In pools and spas, refers to a condition of the water that is neither scaling nor corrosive.
BALL VALVE – A device that can partially or totally obstruct the flow of water, using a ball-shaped diverter.
BARRIER – A means to limit, delay or restrict access to a pool, spa or hot tub (Refer to ANSI/NSPI-8 Model Barrier Code for Residential Swimming Pools, Spas and Hot Tubs).
BASE – A chemical used to raise the pH and/or total alkalinity of pool or spa water.
BASE DEMAND – A measure of the amount of alkaline material required to raise the pH to a predetermined level. This can be accomplished by use of a base demand test, whereby a standard base is added by drops to the pH test solution until the desired pH is reached.
BASIC – Having a pH above 7.0. Opposite of acidic.
BEACH ENTRY or ZERO ENTRY – A sloping entry starting above the waterline at deck level and ending below the waterline in a pool or spa. (Does not refer to sand only.)
BLEACH (sodium hypochlorite) – Also call liquid chlorine. A chlorine source typically having between 5-16 percent available chlorine
BLEEDER VALUE – A device that allows air to be vented from a system.
BOOSTER PUMP SYSTEM – A pump that is completely independent of the filtration and heating system, used to provide support for hydrotherapy jets, cleaning systems and gas chlorinators or special water features.
BREAK IN GRADE – Occurs when the slope of a pool floor changes to a greater slope.
BREAKPOINT CHLORINATION – The practice of adding a sufficient amount of chlorine to water to destroy the combined inorganic chlorine present. Normally, the amount added is 10 times the combined chlorine concentration.
BROADCAST – A method of applying chemicals to a pool or spa by spreading them uniformly over the water surface.
BROMIDE – A salt that contains a bromide ion. Bromide becomes hypobromous acid when reacted with oxidizers such chlorine, ozone, or monopersulfates.
BROMINE – One of several chemicals that yield hypobromous acid when added to water.
BROMINE FEEDER – A device used to add or deliver bromine disinfectant at a controlled rate.
BTU (British thermal unit) – A unit of measurement used to define the capabilities of heaters. One BTU is capable of raising the temperature of one pound of water by one degree Fahrenheit.
BUFFER – Any chemical that, when dissolved in water, will resist pH change. Also any chemical solution used to calibrate pH instruments.
BURNER – The component of a heater where the combustion of fossil fuel takes place.
BYPASS VALVE – A valve used to limit or adjust the amount of water flowing through a device in a bypass loop to divert flow to an alternate plumbing path.
CALCIFICATION – formation of calcium carbonate on walls of pools or pipes, or in a filter or heater, due to precipitation of calcium carbonate.
CALCIUM CARBONATE – An insoluble calcium compound that is the major component of calcium scale. Also, a substance found in nature as limestone or marble.
CALCIUM CHLORIDE – a soluble white salt containing ions and chloride ions, used to raise the calcium hardness of pool and spa water.
CALCIUM HARDNESS – A measure of the amount of calcium dissolved in water, expressed in ppm of equivalent carbonate.
CALCIUM HYPOCHLORITE – A solid white form of inorganic chlorine found in both granular and tablet forms (65-75 percent available chlorine). Because it is an alkaline compound, it will raise the pH of pool and spa water.
CARTRIDGE – A replaceable, porous element designed to retain suspended particles from water.
CARTRIDGE FILTER – A filter that uses a porous element to act as a filter medium.
CAUSTIC – Sodium Hydroxide, lye. In Pools, an extremely high pH alkalizer. Generally refers to high pH.
CAVITATION – The formation of partial vacuums when pump capacity exceeds the water replacement supply.
CENTRIFUGAL FORCE – The outward force exhibited by a circular motion.
CENTRIFUGAL PUMP – A pump that circulates water using a shaft-mounted impeller powered by an electric motor or gasoline engine. The centrifugal force of the spinning impeller creates the flow through the pump.
CF – Abbreviation for the calcium hardness factor in calculating the saturation index of water.
CFM – Abbreviation for cubic feet per minute (of air).
CHECK VALVE – A valve allowing flow in one direction and obstructing flow in the other.
CHECKS (surface) – Spider-web patterns in a surface that do not go all the way through; not an open crack.
CHEMICAL FEED RATE INDICATOR – a mechanism that indicates units (weight or volume) of chemical being dispensed. May require a direct reading or the use of a reference chart.
CHEMICAL FEEDER – A device (floating or mechanical) used to add a chemical to pool/spa water.
CHEMICAL FEED OUTPUT RATE – The weight or volume of active ingredients delivered by a chemical feeder, expressed in units of time.
CHLORAMINE – A compound formed when chlorine combines with nitrogen-containing compounds, e.g., perspiration, ammonia. These compounds can cause eye and skin irritation, and have strong objectionable odors and very low sanitizing capability.
CHLORINATOR – A device used to add or deliver a chlorine disinfectant at a controllable rate. Chlorinators are designed for specific chlorine compounds and should only be used with the compounds for which they are designed.
CHLORINE – A chemical element that exists as a gas in its elemental form, or as a part of a chemical compound. Used as an oxidant and biocidal agent to disinfect pool and spa water.
CHLORINE DEMAND – The amount of chlorine necessary to oxidize all organic matter present in pool water at any given moment, or over a period of time.
CHLORINE NEUTRALIZER – A chemical compound used to reduce chlorine in water, most commonly sodium thiosulfate.
CHLORINE RESIDUAL – The amount of available chlorine remaining in water after the chlorine demand has been satisfied.
CIRCUIT – The complete path of an electric current.
CIRCUIT BREAKER – A device designed to open and close an electrical circuit manually, and to open a circuit automatically at a predetermined overcurrent level, thus providing protection to wiring and electrical components.
CIRCULATION EQUIPMENT – The Components of a circulation system.
CIRCULATION SYSTEM – A system of mechanical equipment and/or components designed to ensure even distribution of heat, chemicals and filtration of water throughout a pool. Includes filters, heaters, pumps, chlorinators, piping, inlets, drains, skimmers and other devices.
CLARIFIER – A chemical that coagulates and neutralizes suspended particles in water. See coagulant or flocculant.
CLARITY – The degree of transparency of pool water. Characterized by the ease with which an object can be seen through a given depth of water.
COAGULANT – A chemical, usually alum, used in pools to gather and precipitate suspended matter.
COAGULATE – To collect, via a chemical compound, suspended matter in pool spa or hot tub water.
COLLECTOR (SOLAR) – An assembly of components used to collect solar energy for heating.
COMBINED CHLORINE – The portion of the total chlorine in chemical combination with ammonia, nitrogen and/or organic compounds; mostly composed of chloramines.
CONCRETE SHELL – Various forms of concrete that, together with steel, form the structure of a pool or spa.
CONTAMINANT – An undesirable organic or inorganic, soluble or insoluble substance in water, including microbiological organisms. Examples: dirt, body oil, algae.
COPING – The cap on the wall that provides a finishing edge around a pool/spa. Can be formed, cast in place, precast or prefabricated from metal or plastic materials, brick or stone. May be used as part of the system that secures a vinyl liner to the top of the pool wall.
CORROSION - The etching, pitting or eating away of a material.
COVE – The radius that joins the floor and wall of a pool/spa.
CRACK (SURFACE) – A repairable break in the surface, not major, not self-curing.
CRACK (STRUCTUAL) – A break or split that weakens the structural integrity of the pool.
DECK DIVE – A dive performed from the deck area of a pool into 5 feet or more of water depth.
DECKS – The area immediately adjacent to or attached to a pool or spa that are specifically constructed or installed for sitting, standing or walking. Generally made of concrete, wood or masonry.
DEEP AREA – Water areas exceeding 5 feet in depth.
DESIGN RATE OF FLOW – The rate of flow used for design calculations in a system.
DIATOMACEOUS EARTH FILTER - A filter that uses a coating of diatomaceous earth (DE) over a porous fabric as its filter medium.
DIATOMITE – the filtering medium of a diatomaceous earth filter composed of microscopic fossil skeletons of the diatom, a tiny freshwater plankton used to trap solids while allowing clear water to pass through the filter. Also known as diatomaceous earth.
DIFFUSER – A pump component that reduces velocity and increases static pressure of fluid passing through a system.
DIGITAL MULTIMETER – A meter read by means of an LED or LCD display.
DISCHARGE HEAD – Resistance to water flow encountered on the discharge side of a pump, measured in feet of head. Each foot of water on the suction side of the pump is equal to one foot of head on the discharge side.
DISINFECTANT – Any chemical used to kill undesirable or pathogenic (disease-causing) bacteria.
DISINFECTION – The killing of pathogenic organisms with chemicals or other proven means, such as ozone, copper or silver.
DPD (DIETHYLPHENYLENE DIAMINE) – A chemical reagent that specifically measures bromine or free available and total chlorine; produces a series of colors from pale pink to dark red.
DRY ACID (SODIUM BISULFATE) – A granular material used to lower total alkalinity and pH in water.
DYNAMIC HEAD – The resistance caused by the friction of the water flowing through an entire circulation system, including the plumbing and equipment and the head pressure measured from the suction and discharge side.
ELBOW – A plumbing fitting shaped at a 90- or 45-degree angle. Also known as an “ell.”
EFFECTIVE PARTICLE SIZE – The theoretical size of sieve (in mm) that will pass 10 percent by weight of the sand.
EFFLUENT – The outflow of water from a filter, pump or pool.
ELECTROLYTIC CHLORINATOR – A device that converts dissolved chloride salt (sodium chloride) into chlorine and its reaction products.
ENCLOSURE – A fenced-in, secured area.
ENERGY (ELECTRIC) – The amount of electricity consumed when power is used over a period of time, measured in kilowatt-hours.
EQUIPMENT AREA – An area used to house recirculation and disinfecting equipment and related appliances.
EROSION – 1. The act of destroying or dissolving by slow disintegration or wearing away.
- In an erosion feeder, the way water dissolves the chemical being fed.
EROSION FEEDER – A flow-through chemical feed device.
ETCHING – Corrosion on the surface; the pitting or eating away of a material such as the surface of plaster (marcite).
EVAPORATION – The conversion of liquid molecules into vapor.
EXPANSIVE SOIL – Clay soil that absorbs moisture and swells, creating the potential for structure damage.
FENCE – A boundary between a pool/spa area and the outside, intended to deter unauthorized entry from the outside. Not intended as a structural barrier to be sat, walked or climbed on.
FERRIC IRON – Compounds of iron that are insoluble in water and will precipitate.
FERROUS IRON – Compounds of iron that are soluble in water and will impart a clear green color.
FILTER – A vessel that removes undissolved particles from water by recirculating the water through a porous substance (A filter medium or elements).
CARTRIDGE FILTER – Uses a porous element that acts as a filter medium.
DIATOMACEOUS EARTH FILTER – Uses a thin coating a diatomaceous earth (DE) over a porous fabric as its filter medium.
PERMANENT MEDIUM FILTER – Uses a filter medium (sand).
FILTER AGITATION – Mechanical or manual movement to dislodge the filter aid and dirt from the filter element.
FILTER AID – A powderlike substance such as diatomaceous earth or volcanic ash used to coat a septum-type filter.
FILTER CARTRIDGE – A filtering element, usually of fibrous material.
FILTER CYCLE – The operating time between cleaning or backwash cycles.
FILTER ELEMENT – A device within a filter tank designed to entrap solids and conduct water to a manifold, collection header, pipe or similar conduit and return it to the pool, spa or hot tub. A filter element usually consists of a septum and septum support, or a cartridge.
FILTER MEDIUM – A finely graded material (such as sand, diatomaceous earth, polyester fabric, anthracite, etc.) that removes solid particles from water.
FILTER SAND - A hard, silica-like substance free of carbonates or other foreign material and used as the medium in sand filters.
FILTRATION – The process of capturing suspended particles and clarifying water.
FILTRATION FLOW – The design rate of flow, in volume over time (gallons per minute, gallons per hour), through the filter system when installed per the manufacturer’s instructions with a new, clean filter medium.
FILTRATION RATE – The rate of water flowing through a filter during a given period of time, expressed in U.S. gallons per minute per square foot of effective filter area. Also known as filtration flow rate.
FIREBOX – A chamber in the pool/spa heater where combustion takes place.
FLOAT VALVE – A valve controlled by the level of a fluid.
FLOCCULANT (FLOC) – A chemical substance or compound that promotes the combination, agglomeration or coagulation of suspended particles in water.
FLOODED SYSTEM – An underwater pump that does not require priming.
FLOOR – The interior bottom surface of a pool or spa.
FLOOR SLOPE – The slope of the pool floor, usually expressed in feet or inches of vertical rise per feet or inches of horizontal distance.
FLOW – The rate of the movement of water, typically in gallons per minute.
FLOW METER – A device that measures the rate of flow of liquid through piping.
FLOW RATE – The volume of liquid flowing past a given point in a specified time period. Usually expressed as U.S. gallons per minute (gpm) or gallons per hour (gph).
FLOW SWITCH – A safety device that prevents a heater from firing if water flow through the system is not adequate.
FLUME – A throughlike or tubular structure, generally recognized as a water slide, that directs the path of travel and rate of descent of the rider.
FLUME SLIDE – Slides of various configurations that are characterized by having deep riding channels, vertical and lateral curves, and high water flows, and accommodate riders using or not using mats, tubes, rafts and other transport vehicles. Included but not limited to family raft rides, inner tube rides, body slides, speed slides, etc.
FREE AVAILABLE CHLORINE – The portion of the total chlorine remaining in chlorinated water that is not combined with ammonia or nitrogen compounds and will react chemically with undesirable or pathogenic organisms. The most active disinfectant in pool/spa water.
FREEBOARD – In a sand filter, the clear vertical distance between the top of the filter medium and the lowest outlet of the upper distribution system.
FRICTION – Resistance created by liquid passing along the inner surface of a conductor pipe and fittings.
FRICTION HEAD – Head specifically caused by friction or drag.
FUSIBLE LINK – A thermal safety cut-off device in the control circuitry that melts at blowback of flame.
GATE VALVE – A device in a pipe that can partially or totally obstruct the flow of water, using an internal “gate” that moves in and out as the valve is operated.
GFCI (GROUND FAULT CIRCUIT INTERRUPTER) – A mechanism that cuts the current to an electrical device the moment a change in voltage occurs.
GRAB BAR/RAIL – A rail used to enter or leave a pool/spa.
GROUNDING – Connecting or providing a conducting path to earth or a conducting body that serves in place of earth.
GUNITE – A pneumatically applied (sprayed) concrete that is a dry mixture of cement, aggregate and/or sand. Water is applied to the mix at the hose nozzle.
GUTTER – Overflow trough in the perimeter wall of a pool, a component of the circulation system.
HAIR AND LINT STRAINER – Readily removable, perforated or otherwise porous container used to catch coarse material. (See NSF definition.)
HALOGEN – Any of the active chemical elements fluorine, chlorine, bromine and iodine, used as disinfectant or oxidizers.
HANDHOLD/HANDRAIL – A device that is intended to be gripped by a user for the purpose of resting and/or steadying him/herself. Typically located inside or outside the pool/spa, or as part of a set of steps or deck-installed equipment.
HARDNESS – The amount of calcium and magnesium dissolved in water, measured by a test kit and expressed as ppm of equivalent calcium carbonate.
HAZARD – A condition or set of circumstances that has the potential of causing or contributing to injury or death.
HEADER – A manifold in a heater that directs the flow of water into and out of the heat exchanger.
HEAT EXCHANGER – A device with coils, tubes or plates that transfers heat from air or a fluid to another fluid without intermixing them.
HEAT LOSS – The natural drop in water temperature as heat is transferred to the surrounding air.
HEAT PUMP – A refrigeration compressor, usually electrically driven, that is operated in reverse. To obtain heat, the evaporator side (cooling coil) is exposed to water, air or ground. The coil transfers the heat from this source to the condenser coil, where it discharges the heat to a pool or spa.
HEATER – An electric, fossil-fueled or solar device used to heat pool or spa water.
ELECTRIC – Uses a heating element immersed in water.
FOSSIL-FUELED - Uses natural, propane gas or fuel oil and an open flame to heat a heat exchanger.
SOLAR - Uses the ultraviolet rays of the sun as a heat source.
Other ways to categorize heaters:
- Direct heaters heat the tubes in which water circulates.
- Indirect heaters circulate steam or hot water inside a heat exchanger, through which pool water flows.
HIGH-LIMIT SWITCH – A temperature control switch that can deactivate a control circuit at a preset temperature. Normally preset at the factory and nonadjustable; must be manually reset.
HORSEPOWER – A unit for expressing the power of motors or engines, equal to a rate of 33,000 foot-pounds per minute.
HOT TUB – A spa constructed of wood with sides and bottom formed separately, and joined together by pressure from surrounding hoops, bands or rods; as distinct from spa units formed of plastic, concrete, metal or other materials.
HYDRAULICS – An engineering process used to pump, filter and return water to the pool that ensures effective circulation of water and chemicals and a lack of dead spots.
HYDROCHLORIC ACID – A very strong acid used in pools or spas for pH control and certain specific cleaning needs, a byproduct of adding chlorine gas to water. Use extreme caution in handling. Called MURIATIC ACID when diluted. See also muriatic acid.
HYDROGEN – The lightest chemical element. A component of water and a frequent product of chemical reactions, Used as a measure of acidity and pH in its ionic for in solution.
HYDROGEN PEROXIDE – A compound of hydrogen and oxygen usually supplied in an aqueous solution, used as a disinfectant.
HYDROSTATIC PRESSURE – The upward pressure of a liquid, commonly ground water, on the bottom of an empty pool or spa.
HYDROSTATIC RELIEF VALVE – A fitting installed in the bottom of a main drain, designed to open automatically or manually to relieve upward ground-water pressure by allowing water to flow into the pool or spa.
HYDROTHERAPY JET – A fitting that blends air water, creating a high-velocity turbulent stream of air-enriched water.
HYDROTHERAPY SPA – A spa unit having a therapeutic use, but which is not drained, cleaned or refilled for each user. Includes, but is not limited to, hydrotherapy jet circulation, hot water, cold water mineral baths, air induction bubbles or any combination thereof. Industry terminology includes, but is not limited to, “Therapeutic pool,” “hydrotherapy pool,” “whirlpool,” “hot tub,” etc. Industry standards exclude facilities under direct supervision and control of licensed medical personnel.
HYPOBROMOUS ACID – The most powerful disinfecting form of bromine in water.
HYPOCHLORINATOR – A chemical feeder through which liquid solutions of chlorine – bearing chemicals are fed into the pool water at a controlled rate. Types of hypochlorinators include: positive displacement, which are usually motor-driven; aspirator which work off a pressure difference in the hydraulic system; and metering, which are connected to the pump suction and used a timing mechanism.
HYPOCHLORITE – Any of a family of chemical compounds including calcium hypochlorite, lithium hypochlorite, sodium hypochlorite, etc. used in various forms as chlorine carriers in pool and spa water.
HYPOCHLOROUS ACID – The most powerful disinfecting form of chlorine in water.
IMPELLER – The rotating vanes of a centrifugal pump; its action creates the flow of the water.
INERTIA – The tendency of all matter to persist in a state of rest or uniform motion until acted upon by some external force.
INFLUENT – The water entering a filter or other device.
INLET, RETURN – See Return inlet.
INLET FITTING – The fitting aperture through which water under positive pressure is returned to a pool or spa.
INSULATOR – In electricity, any device that serves as a nonconductor, usually made of glass or porcelain.
INTERMITTENT IGNITION DEVICE – An electrical spark device used to ignite a gas heater.
IODINE – A chemical element that exists as a grayish-black granule in its elemental state, or as a part of a chemical compound. In the form of liquid iodine and in iodide compounds, a biocidal agent used to disinfect pool and spa water. Chlorine used with iodides releases elemental iodine.
IONIZATION – The process whereby a compound, in solution, separates into charged ions.
ISOCYANURATES (also call ISOS) - A family of pool sanitizer products that are self-stabilizing by containing cyanuric acid. Also Stabilized Chorines.
JETS – See hydrotherapy jet.
KILOWATT – A unit of power equal to 1,000 watts.
KILOWATT HOUR – A unit of work or energy equal to the energy expended by one kilowatt in an hour.
KINETIC ENERGY – The energy from the motion imparted to a liquid by the action of impeller vanes, causing the liquid to flow out of the pump casing and away from the impeller.
LADDER – IN-POOL OR SPA (Type D) – An “in-pool” ladder located in a pool or spa to provide ingress and egress from the deck.
STAIRCASE (Type E) – An “in-pool” staircase ladder located in the pool to provide a means of ingress and egress from the pool to the deck.
LINER – See Vinyl Liner.
LINT STRAINER – A device attached to the front of a pump to which the influent line (suction line) is connected, used to entrap lint, hair or other debris that could damage the pump.
LIQUID ACID – A chemical used to lower pH and total alkalinity, most commonly muriatic acid.
LIQUID CHLORINE – Sodium hypochlorite.
LIQUID PROPANE GAS – The liquid form of propane gas, a heavy hydrocarbon that occurs naturally in petroleum.
LOW WATT DENSITY – In a heating element, the amount of watts generated per inch. The lower the amount of watts per inch, the lower the density.
MAGNESIUM HARDNESS – A measure of the amount of magnesium dissolved in water.
MAIN DRAIN – An outlet located at the bottom of a pool or spa that conducts water to the recirculating pump.
MANIFOLD – A pipe with several openings for making multiple connections.
MANOMETER – An instrument that measures vacuum or pressure differential across an orifice by means of a column of liquid, usually mercury. In pools, usually calibrated to show rate or flow of water in gallons per minute (gpm).
MARCITE – See Plaster
MECHANICAL SEAL – A device used to prevent the passage of water in or out of a centrifugal pump at the motor shaft.
MICRON – One-Millionth of a meter. Used to describe the size of particles that filters are capable of trapping.
MICROORGANISM – A microscopic plant or animal.
MOTOR – A machine that converts electrical energy into mechanical energy. When electrical current is supplied to a series of wires (windings), a magnetic field is created that drives the rotor and shaft of a pump impeller.
MULTIPLE FILTER-CONTROL VALVE – A multiport valve having a number of control positions for various filter operations, combining the function of two or more single valves in one unit.
MULTIPORT VALVE – A device that allows for the multidirectional control of the passage or flow of water through a system.
MURIATIC ACID – Used to lower pH and/or total alkalinity in pool and spa water. See also hydrochloric acid.
NATURAL GAS – Admixture of gaseous hydrocarbons, chiefly methane, occurring naturally underground, often in association with petroleum products.
NEW POOL and/or CONSTRUCTION – The activity of building or installing a pool and/or spa structure and its component parts where no such structure has previously existed.
NITROGEN – An Element introduced into the pool or spa via perspiration, hair spray, cosmetics, etc. Easily combines with chlorine to form chloramines.
NONTOXIC – Having no adverse physiological effect on human beings or other living organisms.
ORGANIC MATTER – In a pool or spa, material introduced to the water by users and the environment such as perspiration, urine, saliva, suntan oil, cosmetics, lotion, dead skin and similar debris.
ORGANISM – Plant or animal life. Usually refers to algae or bacteria-like growth in pool water.
ORIFICE – An opening, usually carefully calibrated in size, through which water flows.
OUTLET – An aperture or fitting through which the water under suction is drawn from a pool, spa or hot tub.
OVERFLOW SYSTEM – A system for the removal of pool/spa surface water through the use of overflows, surface skimmers, and surface water collections systems of various design and manufacture.
OXIDIZERS – Products used to destroy organic waste in water.
PARTS PER MILLION – See ppm.
PATHOGENS – Disease-producing microorganisms.
pH – A valve for the relative acidity or basicity of a substance, such as water, as indicated by hydrogen ion concentration. Expressed on a scale of 0 to 14, 0 being most acidic, 7 being neutral and 14 being most basic.
pH METER – An instrument that measures pH by electrical conductivity across a membrane of an electrode.
PHENOL RED – A dye used in measuring pH.
PILOT LIGHT – A small constant flame used to ignite gas at the first burner.
PINCHING HAZARD – Any configuration of components what will pinch or entrap a user.
PITTING – A form of etching.
PLASTER – A type of interior finish, made from a mixture of white cement and aggregate that will accept a tint or color, applied to a concrete pool or spa. Also called marcite or marblite.
POOL –
INGROUND – Any pool whose sides rest in partial or full contact with the earth (refer to ANSI/NSPI-5 Standard for Residential Swimming Pools or ANSI/NSPI-1 Standard for Public Swimming Pools as applicable).
PERMANENTLY INSTALLED – A pool that is constructed in the ground or in a building in such a manner that it cannot be readily disassembled for storage (refer to ANSI/NSPI-1 Standard for Public Pools or ANSI/NSPI-5 Standard for Residential Inground Swimming Pools as applicable).
RESIDENTIAL – Any constructed pool, permanent or nonportable, that is intended for noncommercial use as a swimming pool by not more than three owner families and their guests and that is more than 24 inches in water depth, and has a volume more than 250 gallons (refer to (ANSI/NSPI-5 Standard for Residential Swimming Pools).
COMMERCIAL/PUBLIC – Any pool, other than a residential pool, that is intended for swimming or bathing and is operated by an owner, lessee, operator, licensee or concessionaire, regardless of whether a fee is charged for use. References within the standard to various types of public pools (refer to ANSI/NSPI -1 Standard for Public Swimming Pools).
PPM – Abbreviation for part per million, the unit of measurement used in chemical testing that indicates the parts by weight in relation to one million parts by weight of water. Essentially identical to the term milligrams per liter.
PRECIPITATE – A solid material that is forced out of a solution by some chemical reaction and settlers out or remains as a haze in suspension (turbidity).
PRESSURE – In a liquid, a form of energy proportional to the depth of a column of liquid. Expressed as pounds per square inch, feet of liquid or feet of head.
PRESSURE CHECK – A test for the rate of water flow; also a test for leaks in a system.
PRESSURE DIFFERENTIAL – The difference in pressure between two parts of a hydraulic system, such as the influent and effluent of a filter.
PRESSURE GAUGE – A gauge that measures the amount of pressure built up within a closed container, such as a filter.
PRESSURE SWITCH – A device that will not allow a heater to fire unless there is adequate water pressure in the system. See flow switch.
PRIMING – Refers to re-establishing the water flow by the recirculating pump.
PSI – Abbreviation for pounds per square inch.
PUMP – A mechanical device, usually powered by an electric motor, which causes hydraulic flow and pressure for the purpose of filtration, heating and circulation of pool and spa water. Typically, a centrifugal pump design is used for pools and spa.
PUMP CAPACITY – The volume of liquid a pump is capable of moving during a specified period of time against a given total head.
PUMP STRAINER – A device, placed on the suction side of a pump, that contains a removable strainer basket designed to trap debris in the water flow with a minimum of flow restriction. Sometimes called a hair/lint pot or trap.
PVC (Polyvinyl Chloride) – A thermoplastic resin commonly used for pool piping and plumbing components.
RATE OF FLOW – The quantity of water flowing past a designated point within a specified time, such as the number of gallons flowing in one minute (gpm).
RATED PRESSURE – Pressure that is equal to or less than the pressure designated on the data plate of the equipment.
REAGENTS – The chemical agents or indicators used to test various aspects of water quality.
REHABILITATION – The activity of restoring all or part of a pool or spa structure and its components to the original design condition, including the rebuilding and/or replacing of worn and broken parts or components.
REMOTE SWITCH – Any switching device used to activate an apparatus from a distance.
REMOVABLE – Capable of being disassembled with the use of only simple tools such as a screwdriver, pliers or wrench.
RESIDUAL – Chlorine residual, or the amount of measurable chlorine that remains after treating water with chlorine.
RETURN INLET – The aperture or fitting through which the water under positive pressure returns into a pool or spa.
RETURN PIPING – Effluent piping.
REVERSE CIRCULATION – A circulation system in which water is taken from the surface and returned through inlets at the bottom of the structure.
SALINITY – The sodium chloride or salt content of water.
SAND FILTER – A filter that uses sand, or sand and gravel, as the filter medium.
SATURATION INDEX – A rating that indicates whether water will have a tendency to deposit calcium carbonate from a solution, or whether it will be potentially corrosive. Four factors are used in the computation: pH, total alkalinity, calcium hardness and temperature. When correctly balanced, water will be neither scale-forming nor corrosive.
SCALE – The precipitate that forms on surfaces in contact with water whose calcium hardness, pH or total alkalinity level is too high.
SEALANT – A liquid, usually clear, that is painted on a surface to prevent the entry of moisture.
SEDIMENT TRAP – A device for trapping sediment that is required on all gas-heater piping.
SELF-PRIMING – A rating given to centrifugal pumps to indicate that the pump is capable of operating above pool water level, after the initial filing with water.
SEQUESTERING AGENT – Synonymous with chelating or metal complexation agent, reacts with potential stain-producing metal ions (i.e., copper, iron, etc.) to reduce staining of pool/spa surfaces and associated colored water.
SERVICE FACTOR – The degree to which an electric motor can be operated above its rated horsepower without danger of overload failure.
SHALLOW AREAS – Areas of a pool or spa with water depths less than 5 feet.
SHOCK TREATMENT – The practice of adding significant amounts of an oxidizing chemical to water to destroy ammonia and nitrogenous and organic contaminants.
SHOTCRETE – A mixture of cement and sand that is applied to contoured and supported surfaces to build a pool and spa. Shotcrete is premixed and pumped wet to the construction site.
SKIMMER (also SURFACE SKIMMING SYSTEM) – THRU-WALL- A device installed in the wall of an inground pool or spa or aboveground/onground pool that allows for continuous removal of floating debris and surface water to the filter.
SKIMMER COVER - A device or lid to close the deck opening to the skimmer housing.
SKIMMER WQUALIZER PIPE – The connection from the skimmer housing to the pool, spa or hot tub below the weir; sized to satisfy pump demand and prevent air lock or pump loss of prime.
SKIMMER EQUALIZER VALVE – The check valve on the equalizer line that opens to draw water when the water level inside the skimmer body drops below operating level, and remains closed during normal skimming.
SKIMMER HOUSING – The structure that attaches to or contains the skimmer weir, strainer basket, float valve and other devices used in the skimming operations.
SKIMMER WEIR – The part of a skimmer that adjusts automatically to small changes in the water level to ensure a continuous flow of water to the skimmer. See weir.
SLIP-RESISTING – Refers to a surface that has been treated or constructed so as to significantly reduce the chance of a user slipping. The surface shall not be an abrasion hazard.
SLOPE – An inclined surface.
SODA ASH (also SODIUM CARBONATE) – A chemical compound in white powder form used to raise pH of water.
SODIUM BICARBONATE – A chemical compound in white powder form used to raise total alkalinity of water.
SODIUM BISULFATE (a DRY ACID) – A granule used to lower the pH and/or total alkalinity of water.
SODIUM THIOSULFATE – A chemical compound used to destroy chlorine.
SOOT – A black, powdery, carbonaceous substance created by a improper air-fuel mixture in the combustion of fossil fuels. A byproduct of incomplete combustion.
SPA (also HYDROTHERAPY SPA) – A hydrotherapy unit of irregular or geometric shell design.
PERMANENT RESIDENTIAL – A spa in which the water-heating and water circulating equipment is not an integral part of the product. Intended as a permanent plumbing fixture and not intended to be moved. (refer to ANSI/NSPI-3 standard for Permanently Installed Residential Spas.)
PUBLIC – Any spa, other than a permanent residential spa or residential portable spa, intended to be used for bathing and operated by an owner, lessee. Operator, licensee or concessionaire, regardless of whether a fee is charged for use (refer to ANSI/NSPI-2 Standard for Public Spas).
SPREAD – The clear distance between the side rails of a ladder.
STABILIZER (also CYANURIC ACID, ISOCYANERIC ACID, CONDITIONER or TRIAZENETRIONE) – A chemical that helps reduce the excess loss of chlorine in water due to the excess loss of chlorine in water due to the ultraviolet rays of the sun.
STAIRS – A series of steps, each consisting of a riser and a tread.
STEPS, RECESSED STEPS, LADDERS and RECESSED TREADS – Means of pool and spa ingress and egress. These elements are intended to be used separately or in conjunction with one another.
STEP(S) – A riser/tread or series of riser/treads extending down from the deck and terminating at the pool or spa floor. Includes recessed steps with risers located outside of user areas.
LADDER – A series of vertically separated treads or rungs connected by vertical rail members or independently fastened to an adjacent vertical pool wall (see ladder for definitions of particular ladder types).
DECK LADDER – Provides deck access from outside the pool or spa.
RECESSED TREADS – A series of vertically spaced cavities in the pool or spa wall, creating tread area for stepholes.
STRAINER BASKET – An easily removable, perforated or otherwise porous container used to catch coarse material in the pump lint strainer.
SUCTION HEAD – Resistance to water flow encountered on the suction side of a pump, measured in feet of head. Reflects the vertical lift required by the pump’s intake.
SUCTION OUTLET – an aperture or fitting, other than a skimmer, on the side wall of a pool or spa through which water under negative pressure (vacuum) is drawn from the pool or spa to the pump or circulation system.
SUCTION PIPING – Influent piping.
SUPERCHLORINATION – The practice of adding a sufficient amount of chlorination compound to water to destroy chlorine demand compounds and any combined chlorine present. Generally, the level of chlorine added is 10 times the level of combined chlorine in the water, See also breakpoint chlorination.
SURFACE SKIMMING SYSTEMS – Refers to perimeter-type overflows, surface skimmers and surface-water collection systems of various design and manufacture. See skimmer.
TAMPER-PROOF – Refers to equipment that requires the use of tolls to alter or remove portions of the equipment.
TEE – A t-shaped plumbing fitting used to connect three pipes.
TEMPERATURE RISE – The difference between the desired water temperature and the current water temperature.
TEST KIT – A device used to monitor specific chemical residual or demands in pool or spa water.
THERM – A unit of thermal measurement equal to 100,000 BTU’s.
THERMOSTAT – A temperature-control device that cycles the heater on and off to maintain the desired temperature.
TIME CLOCK – A mechanical device that automatically controls the time periods that a pump, filter, heater, blower or other electrical device is in operation.
TIME DELAY – A time-controlled switch used to provide a rest period or to stop repeated false starts.
TITRATION – A method of testing the total alkalinity and calcium, and magnesium hardness, of pool, spa or hot tub water.
TOTAL ALKALINITY – The ability or capacity of water to resist change in pH, also known as the buffering capacity. Measured with a test kit and expressed as ppm.
TOTAL CHLORINE – The sum of both the free available and combined chlorines.
TOTAL DISSOLVED SOLIDS (TDS) – A measure of the total amount of dissolved matter in water, e.g., calcium, magnesium, carbonates, bicarbonates, metallic compounds, etc.
TOXIC – Having an adverse physiological effect on human beings or other living organisms.
TREAD CONTACT SURFACE - The foot contact surface of a ladder, step or ramp.
TRICHLORO-ISO-CYANURATE (also TRICHLORO-S-TRIAZINETRIONE) – A form of organic chlorine, most common in compressed form (tablets or sticks), that has 90 percent or more available chlorine, approximately 55.5 percent stabilizer by weight, and an approximate pH of 2.9. See also sodium dichloro-iso-cyanurate.
TURBIDITY – A cloudy condition of water due to the presence of extremely fine particles in suspension that interfere with the passage of light.
TWO-SPEED PUMP – A centrifugal pump with a motor that operates at two different RPM speeds.
UNDERWATER LIGHT – A fixture designed to illuminate from beneath the water surface.
WET NICHE LIGHT - A watertight and water-cooled light unit placed in a submerged niche in a pool, spa or hot tub wall and accessible only from the pool.
VACUUM – The reduction of atmospheric pressure within a pipe, tank, pump or other vessel. Measured in inches of mercury. One inch of mercury equals 1.13 feet of head. The practical maximum vacuum in 30 inches of mercury, or 33.9 feet of head.
VACUUM FILTER – A filter, usually of diatomite type, through which water is pulled by a pump mounted on the effluent side of the filter.
VALVE – Any device in a pipe that will partially or totally obstruct the flow of water (as in a ball, gate or glove valve) or permit flow in only one direction (as in a check or foot valve).
BLEEDER VALVE – Allows air to be vented from a system.
MULTIPORT VALVE – Allows for multidirectional control of the flow of water through a system.
PUSH-PULL VALVE – Allows for dual directional control of the flow of water through a system.
VELOCITY – the speed at which a liquid flows between two specified points, expressed in feet per second.
VELOCITY HEAD – The equivalent distance a liquid must fall to attain a given velocity. The amount of energy, expressed in feet of head, required to accelerate the liquid to a given velocity.
VENTING – A system that introduces air for combustion into the combustion chamber and disperses spent fossil fuel or flue products.
VENTURI JET – A tube mounted in a waterline, meant to cause restriction of flow. The constriction causes a change in velocity of water through the tube, resulting in a pressure differential that is proportional to the flow rate.
VINYL LINER – A plastic membrane constructed of vinyl or vinyl compounds that acts as a container for water.
EXPANDABLE LINER – Constructed of a material that has the capacity to stretch into a shape other than the original construction dimensions.
HOPPER LINER – Used to obtain greater depth by geometrical pattern on the liner bottom or floor to fit a predetermined size and shape.
VOLTS – The measure of electrical potential or electromotive force in units.
VOLUME – Capacity; the amount of water expressed in gallons or liters that a pool/spa will hold.
WALLS – The interior pool or spa wall surfaces consisting of surfaces from the plumb to a 45-degree slope.
WASTEWATER DISPOSAL SYSTEM – All water disposal systems approved by (state or local) authority, such as a storm sewer, sanitary sewer, open pit, leach field or irrigation system.
WATERLINE –
Overflow System - The waterline is at the top of the overflow rim.
Skimmer System – The waterline is at the midpoint of the operating range of the skimmers when there are no users in the pool/spa.
WATER PRESSURE SWITCH – A switch that, for water flow, detects abnormally low pressures on a piece of equipment and can shut it off.
WATT – The measure of electrical power computed by multiplying voltage times current (volts x amperes). Equal to 1/746th of one horsepower unit.
WATTS VALVE – A mechanical valve that opens with high pressure or high temperature, used a safety device on fossil-fuel heaters.
WEIR – A device included with a through-the-wall or over-the-wall skimmer that controls the amount of surface water (flow) drawn into the skimmer and filtration system. See also skimmer weir.
WINTERIZING - The process of preparing a pool or spa for freezing weather, includes chemical treatment of the standing water, plus physical and chemical protection against freezing of the pool or spa and its equipment.
WRINKLE – A small ridge or crease in a otherwise smooth surface.
|
