Acrylonitrile-Butadiene-Styrene – Rigid black plastic pipe used for drain / waste / vent lines.
Air admittance valve
Also known as a cheater vent – is a device that allows air to enter the drainage system, but stops sewer gasses from leaving. Although these are acceptable in some circumstances; such as an island vent, they are frowned upon, hence the name cheater vent.
A covered opening that allows access to service a plumbing system
A device attached to the end of a faucet that mixes air into flowing water
A device mounted at the back of a kitchen sink, connecting to the drain line between a dishwasher and disposer to allow the dishwasher to discharge freely into the disposer while preventing contaminated water from siphoning back into the dishwasher
Blockage liquid flow of liquid (i.e. on suction side of pump) caused by an air bubble in the line
An angle stop is shutoff valve between water pipes and a faucet. The inlet connects to the water-supply pipe in a wall, the outlet angles up 90° to the faucet
A sacrificial rod installed in a water heater. It is composed of one or more metals that protect the tank from corrosion and extend tank life.
A shower mixing valve that automatically maintains balance between incoming hot and cold water supplies by immediately regulating fluctuations in pressure. As a result, temperature remains constant, though the outlet pressure may drop. Also known as a pressure-balanced valve.
Preventive device for back-flow of liquid such as on sprinkler systems to prevent water from trickling back into the feed supply
Aqua stat is a thermostat that is submerged in water. It is used to control operation of a specific device.
Auxiliary water supply
An auxiliary water supply that is in addition to the primary supply. Example: your home is connected to municipal water supply and you also have well water available.
System water is going in the opposite direction from normal flow.
A device installed in the piping system to prevent backflow of water. Examples: check valve, double check valve, and reduced pressure principle backflow preventer, air gap.
Pressure that resists the flow of fluid in a piping system
Back-Siphenage is negative pressure in the piping system which results in backflow. Commonly prevented with a vacuum breaker or air gap
The process of cleaning a filter by reversing the flow of water through the system. Accumulated sediments are sent to waste.
Overflow of a plumbing fixture due to drain stoppage
Used in drainage systems to prevent backflow
An object placed in an appliance to change the direction of, or retard the flow of air, air-gas mixtures, or flue gases
A valve that uses a ball to seal against the seat
Controls the flow of water from the water supply line into a gravity-operated toilet tank. It is controlled by a float mechanism in the tank water.
Device that attaches to a garden hose. Used to loosen drain blockage
Basket-shaped strainer with holes and a slot that fits the sink drain to allow water to run out but to catch food or other solids before they can enter the sewage system.
Term to describe the common bathroom. One toilet, one sink, one bathtub/shower.
A personal hygiene plumbing fixture similar in appearance to a toilet bowl used for washing genitals and posterior areas of the body. It is mounted on the floor next to a toilet and consists of a washing basin, a hot and cold faucet, and sprayer.
Also called a “blowfish” it is a drain-cleaning device consisting of a rubber bladder with a hose fitting one end and a nozzle on the other. The device attaches to a water hose and is inserted into a clogged drainpipe. As water is introduced, it expands to grip the pipe, and releases pulsating bursts of water through the nozzle, forcing water through the pipe to clear the obstruction.
Partial venting or draining, under pressure, of the water side of a boiler to reduce or remove unwanted contaminants. Also the pressure drop after releasing a pressure-relief valve.
A sealed tank where water is turned to steam for heating or power
A strong solution of sodium chloride (salt) used in the regeneration of ion exchange water softeners
British thermal unit – Used for both heating and cooling, BTU is a measure of the heat given off when fuel is combusted. Or for cooling, it’s a measure of heat extracted from your home. (One BTU is approximately equal to the heat given off by a wooden kitchen match.)
A British Thermal Unit (BTU) is the unit of heat required to raise 1 pound of water by 1 degree Fahrenheit. BTUH is British Thermal Units per Hour.
The lowest drain pipe in your system also known as the Main drain
A set of valves installed before a water softener so water can be bypassed when water softener needs repair
- Pumps: The flow rate in gallons per minute or liters per minute
- Water softeners / conditioners: Quantity of undesirable matter that can be removed by a water conditioner under standard test conditions. For ion exchange water softeners, this is expressed in grains of hardness removal between regeneration’s and is related to a pound of salt used.
- Water filters: For filters, capacity may be expressed in the length of time or total gallons delivered between servicing.
- Water heaters: The size in gallons of water of the storage tank (e.g. 40 gal, 75 gal, etc.)
(CO2) A gas present in the atmosphere, formed by the decay of organic matter; the gas in carbonated beverages; dissolved in water it forms carbonic acid.
A colorless, odorless, highly poisonous gas produced when carbon-based fuels, such as natural gas, burns without sufficient air nearby.
Heavy metal made of casting on molds to make fixtures such as sinks, tubs and lavatories, covered with a porcelain enamel coating. Casting is made of a series of alloys primarily of iron, carbon, and silicon.
The vacuum created when the discharge capacity of the pump exceeds the replacement in the suction line. This causes bubbling and vibrations that can damage the pump if they occur over an extended period
Stands for Cubic Feet per Minute – A measurement of airflow that indicates how many cubic feet of air pass by a stationary point in one minute. The higher the number, the more air is being forced through the system.
A device that allow flow in only one direction
CI / Cast Iron Pipe
Also known as Soil Pipe, No Hub pipe is used in certain locales and for commercial buildings for soil stacks. It cannot be soldered, threaded, or welded, and can only by connected by steel banded rubber sleeved adapters
A fitting installed in the drainage pipe to allow cleaning and inspection
A system where the incoming cold water supply has a device that will not allow water to expand when heated. (I.e. check valve, backflow preventer, pressure reducing valve, etc.)
An anchoring ring that attaches to the closet bend and secured to the floor. The heads of closet bolts, used to secure the toilet in place, insert into slots in the closet flange
The location where combustion takes place
Gases released when a gaseous, liquid, or solid fuel reacts at an elevated level that needs to be vented with gas or oil-fired water heaters
A unit that controls the pressure applied to the refrigerant
Water vapor that separates from products of combustion due to a reduction in heating surface temperatures to below the dew point of surrounding air. Water formed when water vapor formed in gas combustion loses heat before it passed out of the venting system.
A water condition of low pH (acid condition) that can corrode metal pipes, pool fixtures and pumps (Unbalanced water)
Chlorinated Polyvinyl Chloride- Rigid plastic pipe used in water supply systems, where code permits. With stands high temperatures – Available in straight or in rolls
Cold water or clothes washer
A type of “valve” used on a water heater or boiler system that opens or closes to control flue gases
Decibels (dB) are a unit measuring the intensity of noise
Describes a faucet that is mounted on the deck of the bathtub enclosure, rather than on the rim of the bathtub or on the wall. Also referred to as a Roman spout faucet. Also known as a sunken tub, the deck-mount tub is usually mounted on a platform and has no apron or decorative side.
The process of reducing water to a non-mineral state by passing it over a bed of resins
Water free of inorganic materials
A pipe that is capped off
Diameter of Plumbing pipe or fixture
Tube inside the water heater that sends cold water to the bottom of the tank
A system that pulls outside air for combustion and vents combustion gases directly outside without using a chimney.
All of the pipes, fittings and fixtures that waste water drain into.
A device fitted in the flue way of a gas appliance to prevent updraft, downdraft, or the secondary flue blockage from obstructing the escape of combustion gases.
Coupling pipes together without any glue or solder to ensure a proper fit.
Drainage, waste and vent
The pressure when the water is flowing.
Energy Efficiency Ratings (EER) measures the efficiency with which a product uses energy to function. It is calculated by dividing a product’s BTU output by its wattage.
A product’s ability to utilize input energy, expressed as a percentage
Septic system liquid waste
A mechanical device for pumping sewage from below the sewer line
A process which uses an electrical current and an arrangement of permeable membranes to separate soluble minerals from water. It is often used to desalinate salt or brackish water
A process involving chemical change caused by the passage of an electric current through a liquid
Heating unit in an electric water heater
Emergency floor drain
A floor drain that is not expected to be regularly used
ENERGY STAR® is a government-backed program helping businesses and individuals protect the environment through superior energy efficiency. Products with the ENERGY STAR rating will be efficient and save cost on energy bills.
A tank designed to absorb excess pressure due to thermal expansion. (E.g. closed system)
Liquid that has been passed through a filter
The rate at which the water is traveling through the filter, measured as GPM (gallons per minute) per sq. ft.
Water that has completed a purification or treatment process
Materials that fill the opening around penetrating items such as cables, cable trays, conduits, ducts, and pipes and their means of support through the wall or floor to prevent spread of fire
First Hour Delivery
Rating based on the combination of the usable stored volume of hot water in a tank plus the recovery capacity for the first hour of operations.
Anything that discharges sewage or clear water waste – Example: Sink, water closet, bath tub, floor drain or washing machine.
The section of pipe between the trap serving a fixture and another part of the drainage system
Fixture outlet pipe
The pipe that connects the fixture to the trap
A theoretical measurement of the amount water a fixture will need supplied and is likely to discharge to the drainage system.
The part on the bottom of the toilet tank that opens to allow water to flow from the tank into the bowl
(Lifting Flames) An undesirable burner operating condition, usually indicating incomplete combustion in which flames leave the burner port to “reach” for combustion air.
Flood level rim
The level of a fixture where water will begin to overflow
Receptacle usually made of enameled cast iron located at floor level and connected to a trap to receive the discharge from indirect waste and floor drainage. Cleaner and more sanitary than regular floor drains. Usually used in hospitals & restaurants.
Rated in gallons per minute (GPM) or in gallons per hour (GPH)
A passageway for combustion by-products
A device to minimize heat loss through a venting system
Toilet valve that automatically shuts off after it meters a certain amount of water flow.
Flushometer Tank System
Toilet flushing system that uses supply water pressure to compress water to provide a pressurized flush as opposed to a gravity flush tank.
The valve located at the bottom of a gravity-operated toilet flush tank, which opens when the trip lever is actuated, and closes when the tank has drained to the desired level. Usually also contains an overflow tube.
The loss of pressure caused by the turbulence created in water while traveling through the pipe.
The depth to which frost penetrates the earth
Gallons per Flush used in toilets. Current law requires maximum of 1.6 gpf. Older styles were usually 3.5 gpf.
Grains per Gallon. A measurement of the amount of dissolved material in water. One grain per gallon equals 17.1 ppm
Gallons per Hour. A measure of flow rates
Gallons per Minute. The rate of flow by which faucets and showerheads are measured and regulated
Gas Control Device
Is used to regulate gas pressure on a water heater
A gate valve with a curved chamber
Gravity Operated Toilet
A toilet that relies on the natural downward pressure of water in a toilet tank to flush the toilet effectively
Grains per Gallon (gpg)
A common basis for reporting water analyses in the United States and Canada; one grain per U.S. gallon equals 17.12 milligrams per liter (mg/1) or parts per million (ppm). One grain per British (Imperial) gallon equals 14.3 milligrams per liter or parts per million.
Waste water from sinks, showers, and bathtubs, but not toilets
A device that captures grease entering a system before it reaches the sewer lines. Usually used in commercial applications such as restaurants or cafeterias
Naturally occurring water rising from the water table of the surrounding land
Connecting a piece of electrical equipment to a “ground wire” which is connected to the electrical system ground at the circuit breaker box. This helps to ensure that the circuit breaker will trip and cut off power in the event of a short circuit or damage to insulation.
Natural water containing impurities in various proportions. Traditional hardness is a measure of calcium or dissolved solids in a solution, measured in parts per million. Hard water generally ranges from 100 to 250 ppm.
The amount of dissolved minerals in water measured in grains per gallon (GPG). The most common minerals are calcium and magnesium.
The heat exchanger is a separate tank that contains non-potable fluid that transfers heat to potable water heater.
A product that works just like an air conditioner in cooling mode; however, in heating mode, the refrigerant flow is reversed and heat is extracted from the outside air too heat your water.
An outdoor faucet also used to supply washing machines.
Hot water tank
The Heating Seasonal Performance Factor is a measure of the heating efficiency of a heat pump. The higher the HSPF number, the more efficiently the heat pump heats your water.
Term used for Heating, Ventilation, and Air Conditioning.
Hydro Jetting (Service)
The process of clearing blocked pipes using high pressure water as a boring and flushing mechanism
Iron Pipe Size (OD). Same as NPS. Standard pipe threads. Also Internal Pipe Swivel connection (female)
International Standards Organization based in Geneva Switzerland. Among the many standards it issues are pump and seal standards for the metric community.
A series of five standards for developing a total quality management system. Developed by the International Standards Organization
Indirect service water heater
A water heater that is heated with steam, hot water, or warm air from another source. Example: a coil from a hot water boiler heats the water.
Has a physical separation. Example: Boilers drain which terminates above a floor drain.
A vent pipe that vents only one fixture
A reversible process in which ions are released from an insoluble permanent material in exchange for other ions in a surrounding solution; the direction of the exchange depends upon the affinities of the ion exchange for the ions present, and the concentrations of the ions in the solution.
The process in which atoms gain or lose electrons – sometimes used as synonymous with dissociation, the separation of molecules into charged ions in solution
Instantaneous Water Heater
A type of water heater that heats water as it flows through a heat exchanger coil
Stops that allow the owner to shut off water supply at the faucet for maintenance without shutting off the water supply to the entire house.
Integral Vacuum Breaker
A device typically used in a sink or shower sprayer to keep water from back-flowing into the fresh water supply.
For separating grease and oil from drainage system (See grease trap.)
Usually refers to the heating/ cooling jacket surrounding the stuffing box on some pumps; the outer casing (shell) of a water heater
An orifice or other feature of a toilet that is designed to direct water into the trap way quickly to start the siphon action
Utility area where incoming current is connected in an electrical appliance
Kilowatt – A measure of the rate of supply of energy or power, equal to 1000 watts or 3412 BTU per hour
One thousand watts
PVC test plug
Lateral Sewage Line
A sewage line that connects one sewage pipe with another
Very deep sink used in a laundry room for soaking or washing clothing
A fixed bowl or basin with running water and drainage for washing – Bathroom sink
Porous soil area, through which septic tank leach lines run, emptying the treated waste
Pipes that carry effluent from the septic system out to the leach field
Loss of fluid usually due to mechanical breakdown or gasket wear
An air-gas mixture that contains more air than needed for complete combustion of the gas
A pipe that carries rainwater to the ground or sewer
A legal right to hold another’s property, or to have it sold, or applied for payment of a claim, especially to satisfy a debt
A written document from the contractor to the owner that releases the Lien (mechanic’s or material) following its satisfaction
A written document from a contractor or material supplier having lien rights against an owner’s property that relinquishes all or part of those rights.
See Floating Flame
A series of calculations done to determine load requirement needed to properly size a piece of equipment.
Low Boy is a type of water heater configuration in which the water heater is lower in height and occupies more floor space. Mostly used for limited space in cabinets and closets.
Low Consumption Toilet
A class of toilet designed to flush using 1.6 gallons of water or less. Also known as “Water-saving” toilets
Liquid Propane – A fuel for gas water heaters
One of the elements in the earth’s crust, the compounds of which when dissolved in water make the water hard. The presence of magnesium in water is a factor contributing to the formation of scale and insoluble soap curds
The primary artery of supply of the water supply or drain system in which all the branches connect. In the case of drains, known as the Main Vent
An element sometimes found dissolved in ground water, usually with dissolved iron but in lower concentration; causes black stains and other problems similar to iron. It can be removed by a water softener or it can be precipitated by chlorine at a pH of 9.5 or above.
Greensand that has been processed to incorporate in its pores and on its surface the higher oxides of manganese. The product has a mild oxidizing power, and is often used in the oxidation and precipitation of iron, manganese and/or hydrogen sulfide, and in their removal from water.
Access opening to a hole, usually with a cover, through which a person may enter a sewer, boiler, drain, etc. (usually round to prevent the cover from falling into the opening)
A fitting that connects a number of branches to the main; serves as a distribution point
A unit of measure, one thousandth of a meter. Used to describe the pore size of filters
Mixes hot and cold water to achieve a specified delivery temperature
Water supplied by a city for public use; tap water. Usually held in a reservoir.
A colorless, odorless fuel derived from the earth, consisting primarily of Methane (CH4). Odors are added to aid in leak detection
Neo Angle Base
A shower base designed to allow the shower to fit into a corner using minimal floor space while maintaining an elegant look
Less than atmospheric pressure
Net Usable BTU
That portion of a fuel’s heat energy actually transferred into the water by a heater
A short length of pipe installed between couplings or other fittings
A tool used to unscrew sections of pipe
A connector for no-hub iron pipe consisting of a rubber sleeve and a stainless steel band secured by hose clamps. A variation, a neoprene sleeve with two adjustable steel bands, is used for connecting dissimilar materials, as when connecting new plastic pipe to an existing cast-iron drainpipe
Not containing iron
Water that is not safe to drink
Original Equipment Manufacturer.
A toilet in which the tank and bowl are manufactured as a single vitreous china fixture. One-piece toilets usually have a lower profile than two-piece toilets.
The term used to describe a pipe that connects two parallel pipes. Some offsets in a drainage system may require an offset relief vent.
The day-to-day cost of running your home comfort equipment, based on energy use.
An opening through which gas is discharged and whereby the flow of gas is limited and/or controlled.
The vertical tube inside a toilet tank that directs water into the bowl in case the ballcock malfunctions. It is usually part of the flush valve. It prevents potential water damage caused by a tank overflow. A “constant-running” condition alerts the user to a problem. On most toilets, the overflow tube also has a refill tube flowing into it, which directs water from the ballcock through the overflow tube to the bowl, after a siphon break.
A calculation of saving to determine length of time a unit will take to pay for its self.
Cross linked polyethylene piping
Potential Hydrogen – The hydrogen ion concentration of water to denote acidity or alkalinity, measured on a scale of 0 to 14. Below 7 denotes acidity; above 7 denotes alkalinity
Water that is safe to drink
An adjustable resistor used to vary the sensing distance of the touch-less faucet
Mechanical draft exhaust to outside, usually utilizing room air to support combustion
A water storage tank pre-charged with air at factory featuring a vinyl bag to separate water from air which prevents water-logging. This tank design provides greater draw-down than standard tanks. Pre-charged tanks do not require air volume control
Pressure Balanced Valve
A shower mixing valve that automatically maintains balance between incoming hot and cold water supplies by immediately regulating fluctuations in pressure. As a result, temperature remains constant, though the outlet pressure may drop. Also called an anti-scald valve
Opening in bowl through which tank-supplied water flows, designed to propel waste up into the trap way
Pressure reducing valve is used to reduce incoming water pressure to a building. High water pressure is one of the most common underline issues with most plumbing repairs. Lower water pressure leads to less plumbing repairs.
Pounds per square inch
Pounds per square inch gauge
A fitting or piping arrangement designed to prevent sewer gasses from entering the home; by keeping a section of the pipe filled with liquid.
A common sewer directly controlled by public authority.
Polyvinyl Chloride – A rigid white or cream-colored plastic pipe used in non-pressure systems, such as drainage, waste, and vent systems
Recovery Factor – Rating based on the efficiency of the product which is input required to raise 1 gallon of water 1 degree Fahrenheit.
Water supplied to the plant before any treatment
The amount of water in gallons that can be heated in one hour (gph)
The amount of water in gallons per hour raised 100 degrees F at a given thermal efficiency and BTU per hour input.
A type of compressor used in hybrid water heaters that compresses refrigerant by using a type of “piston” action
Water which has a reddish or brownish appearance due to the presence of precipitated iron and/or iron bacteria
The tube that directs water from a ballcock into the overflow tube to refill the bowl after a siphon break
An additional vent to increase air flow in a branch or stack
Return Circulation System
Tempered water from or near the point of usage which eliminates waste of hot water used for long runs and adds storage to the system
A water treatment method whereby water is forced through a semi permeable membrane which filters out impurities
A water supply pipe that goes through at least 1 story
Safe Drinking Water Act
An amendment to the Public Health Service Act, which was passed in 1976 to protect public health by establishing uniform drinking water standards for the nation. In 1986 SDWA Amendments were passed that mandated the EPA establish standards for 83 drinking water contaminants by 1992 and identify an additional 25 contaminants for regulation every 3 years thereafter.
Safety Shutoff Valve
A device on a gas appliance that shuts off the gas supply to prevent a hazardous situation. A flame safety shutoff operates when the actuating flame becomes extinguished.
House drain that carries wastewater away from the house to a sewer system or septic tank
Sanitary building drain
A building drain that carries sewage from the upper most water closet (toilet)
A specially designed compressor that works in a circular motion vs. an up and down piston action.
The Seasonal Energy Efficiency Ratio is a measure of the cooling efficiency of your air conditioner or heat pump. The higher the SEER number, the more efficient the system is at converting electricity into cooling power.
Sealing of combustion chamber to prevent spillage of combustion products
Sealed Combustion Heater
A heater which pulls combustion air from outside the structure and vents combustion by-products to the outside
The substance that settles on the bottom of a water tank. Also known as lime
Pipe connecting the water company piping to the water meter
Service water heater
A water heater that heats the water independently of other heat sources. Example: electric water heater.
Waste water that is not clear water or storm water. Water discharged from a kitchen sink is considered sewage.
Usually refers to angle stops installed under sinks and toilets, but also valves installed on branch lines and alongside the meter
Slip joint or soldered joint
A pipe that carries sewage in the sanitary drainage system.
A soil-or-waste pipe that goes through one or more stories.
Stainless steal braided supply line for water piping to fixtures.
A vent pipe that extends from the top of a soil-or-waste stack and connects to vent header or terminates outside.
A tank used to hold a specific volume of water
Drain used to receive and convey rain water, surface water, and ground water away from buildings
The vertical distance between two floors.
Subsoil drainage pipe
An underground pipe designed to convey ground water away from a structure. Also known as weeping tile.
Term for soldering. Also formation of condensation on the outside of pipes or toilet tanks.
T & P
Temperature and pressure relief valve. Used on water heater and boilers as a safety valve to prevent unit from exploding if unit malfunctions. Don not ever remove or cap t & P valves or there drain lines.
Tank-less Water Heater
Instantaneous water heater
Temperature Differential Controller
Controller used to measure temperature difference between storage tank and solar panels. Controller will turn pumps on and off as needed to keep storage tank hot
An in-line hot / cold mixing valve
Small electric generator. Electron flow between the hot junction of 1200 degrees F and cold junction of 600 degrees F creates millivoltage.
Apparatus that consists of a number of thermocouples combined so as to multiply the effect and is used for generating electrical current.
Unit that monitors and controls your water heater temperature
Thermostatic Expansion Valve
A thermostatic expansion valve (TXV) is precision device used to meter the flow of liquid refrigerant entering the evaporator at a rate that matches the amount of refrigerant being boiled off in the evaporator.
Ability to transfer and absorb heat from fuel sources into the water
The effect of water expanding when heated
A fitting or piping arrangement designed to prevent gasses from entering the home; by keeping a section of the pipe filled with liquid.
The section of pipe between the vent and the trap weir.
The top of the bottom part of the trap.
Trap seal depth
The vertical distance between the trap dip and the trap weir.
The point on a trap where water will begin to flow down the trap arm.
UL is an objective, non-profit organization that tests and rates electrical products for public safety.
Universal Plumbing Code
A system of procedures designed to provide consumers with safe and sanitary plumbing systems and used throughout the United States by local jurisdictions
Deep fixed basin, supplied with hot and cold water, which is used for rinsing of mops, disposal of cleaning water
A bathroom storage cabinet under the wash basin
A pipe that allows air into a drain system to balance the air pressure, preventing water in the traps from being siphoned off.
A vent that connects stack vents and vent stacks to outside air.
A vent pipe that is connected to a soil-or-waste stack below the lowest soil-or-waste pipe connection and terminates outside or connects to a vent header.
The pipes and fitting that provide air circulation for the drainage system.
A ventilator captures heating or cooling energy from stale indoor air and transfers it to fresh incoming air.
A short tube with a tapered constriction in the middle that causes an increase in the velocity of flow of a fluid and a corresponding decrease in fluid pressure and that is used for creating suction in a vacuum pump
Water closet (toilet)
Water distribution system
All of the pipes and devices that provide water to the fixtures
A loud banging noise caused by the hydraulic shock of suddenly shutting off a water supply, where water moves against the side of containing pipe or vessel
Water Hammer Arrestor
A device installed near a fixture to absorb the hydraulic shock caused by a sudden shutoff of water.
Water service pipe
The water supply pipe to a building
Level below the earth’s surface at which the ground becomes saturated with water.
A soil-or-waste pipe that is also a vent. Wet vents are sized to allow for air and water to occupy the pipe.
A style of bathroom lavatory faucet having separate spout and handles, usually 8″ from center of handle to handle
Maximum pressure of the operating system permissible
A flame condition caused by too severe a reduction in primary air. The yellow color is caused by glowing carbon particles in the flame. It can be corrected by the injection of more primary air.
Usually a brass casting that holds both the hot and cold valves and the mixing chamber for the water. May also refer to an assembly of copper or other metal which serves the same function
A pipe connecting upward from a soil or waste stack to a vent stack for the purpose of preventing pressure changes in the stacks.
Water with a total hardness less than 1.0 grain per U.S. gallon, as calcium carbonate
Zone of Aeration
The layer in the ground above the water table where the available voids are filled with air. Water falling on the ground percolates through this zone on its way to the aquifer.
Zone of Saturation
The layer in the ground in which all of the available voids are filled with water