Confused? See commonly used pluming terms

Terms Used

Various Plumbing Industry Terms

Do you sometimes feel left out when it comes to talk of sump pumps, plumbing, etc.?

Here is a glossary of commonly used terms from the plumbing industry related to sumps, pumps, and the like.

Alphabetical listing of commonly used plumbing terms

AC Alternating Current. Electrical supply in which the polarity of the wire reverses rapidly.
ANSI American National Standards Act
ASME American Society of Mechanical Engineers
Air Gap A device mounted at the back of a kitchen sink or at any drain connection, between a dishwasher and disposer, a downspout or sump pump discharge and the underground conduit, etc. This allows the discharge water to move freely into the drain pipe while preventing contaminated water from siphoning back into the device.
Air Lock Blockage of flow of liquid (i.e. on suction side of a pump) caused by an air bubble in the line.
Anti-Siphon Preventive device for back-flow of liquid such as on sprinkler systems, sump pumps, etc. to prevent water from trickling or reversing back into the feed supply.
Back Flow The act of water traveling from one system back into any part of the main distribution system (usually by siphoning).
Back Flow Preventer A device to prevent backflow i.e. into a potable water supply. Usually required for sprinkler systems, handheld showers, pullout faucet spouts, kitchen sprayers, toilets, and other devices that connect potable water supplies to potentially contaminated effluent, etc. 
Back Pressure Pressure that resists the flow of fluid in a piping system.
Back Siphon-age The negative pressure that causes backflow.
Backup Overflow of a plumbing fixture due to drain stoppage.
Backup Sump Pump Secondary or auxiliary sump pump. Typically runs on alternative energy source such as water pressure or battery power, usually designed to take over when the primary sump pump fails because of mechanical or power failure.
Ball Valve, Ball Cock A valve that uses a ball to seal against the seat. Usually identified by the 90 degree full on/off style of handle and these are usually full port or near-full port valves allowing little or no restriction in the line.
Bernoulli's Law The principle that a stream of liquid or gas exerts less sideways pressure while in motion than while at rest. As a result, fluids seem to be drawn into the stream, but are really pushed in by higher outside pressure.
Brackish Water Water containing bacteria between 1.000 and 15,000 PPM of dissolved solids, often mixed with strong salt or other contaminants.
Braided Tubing A flexible pressure tubing of synthetic material encased in braided threads of steel, usually chrome plated or stainless. The braiding protects the tube from damage due to internal pressure, abrasion, or crimping. Often used in water supply lines for toilets, sinks, water heaters, etc.
Brine A strong solution of sodium chloride (salt) used in the regeneration of ion exchange water softeners. Sometimes used to melt ice in drain lines, such as outside sump pump discharge pipes.
Bushing A pipe fitting used to join two pipes of different sizes. A threaded bushing is threaded inside and out. A socket bushing is smooth inside and out and is designed to connect a smaller-sized pipe into a larger-sized fitting.
CC Copper to Copper soldered.
Capacity Pumps: The flow rate in gallons per minute (hour) GPM/GPH or liters per minute (hour) LPM/LPH
Cast Iron 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.
Cavitation The vacuum created when the discharge capacity of a 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. This can happen when the suction opening of the pump or the feeder pipe to the pump is smaller than the pumping capacity of the pump. This essentially "starves" the pump as it is running and can cause pump failure or damage.
Centrifugal Pump A pump that moves water by centrifugal force developed by rapid rotation of an impeller. As the rotating impeller whirls the water around, centrifugal force builds up pressure forcing the water through a discharge outlet.
Check Valve A type of reverse-flow or back-flow preventer installed in a pipe run that allows water to flow in only one direction.
Cleanout Plug A plug in a trap or drain pipe that provides access for the purpose of clearing an obstruction.
Close Nipple Short lengths of pipe that are threaded on both ends. The threads are so close together they almost join in the center. This can also be a very short length of plastic pipe used to place two fittings very close together.
Cock A faucet or valve for regulating or stopping the flow of water.
Combined Sewer A sewer system that carries both sanitary waste and storm water runoff.
Compression Fitting A kind of tubing or pipe connection where a nut, and then a sleeve or ferrule is placed over a copper or plastic tube and is compressed tightly around the tube as the nut is tightened, forming a positive grip and seal without soldering or gluing. Also a flexible connector that has a nut and gasket designed to attach directly to an SAE standard compression thread, without the use of a sleeve or ferrule.
Compression Valve A type of valve that is often used for water faucets. It is opened or closed by raising or lowering a horizontal disk by a threaded stem. This type of valve uses compression fittings to make connections to the tubing.
Corrosion The disintegration of a metal by electrochemical means.
Corrosive Water A water condition of low pH (acid condition) that can corrode metal pipes, pool fixtures and pumps (Unbalanced water).
Cross-Connection Any connection or situation that may allow wastewater to enter the potable water supply system.
Curb Cock Shutoff A valve normally used with water meters set between the meter and the building, or the meter and the main street supply line.
DWV Drainage, Waste, and Vent systems, which remove wastewater. Not for drinking water.
Discharge Head Difference in elevation between the liquid level of the discharge tank or sump and the centerline of the pump. Also includes any additional pressure head that may be present at the discharge tank fluid surface. Often used when determining the height of the vertical rise of the discharge of a pump.
Discharge Tube Outlet tube that connects a disposer or sump pump to the drain line.
Dope Pasty lubricant used to seal pipe threads prior to making a threaded pipe connection.
Drain Any pipe that carries wastewater or water-borne waste.
Drawdown The distance the water level drops below the standing water level while the pump is operating.
Duplex Basin An ejector pump container, usually 30" x 36" or 36" x 36" large enough for two pumps, used in multi-family buildings.
Dynamic Pressure The pressure when the water is flowing.
Eductor A device utilizing a nozzle and throat, installed in a stream of water to create a partial vacuum to draw air or liquid into the stream; commonly used to draw regeneration chemicals into an ion exchange water treatment system, such as a softener or deionizer. Also used in water powered sump pumps to draw sump water up and discharge it to the exterior of the home.
Elbow A fitting with two openings that changes the direction of the line. Also known as an ell. It comes in various angles from 22½ degrees to 90 degrees; often referred to by their angles (i.e.45, 90).
Elevation The vertical distance between the level where fluid enters a pipe and the level where it leaves. It must be added to the Total Discharge Head if the inlet is lower than the outlet and subtracted if the inlet is higher.
Eye of the Impeller The center of the impeller, where the fluid enters.
FIP Female Iron Pipe connection. Standard internal threads on pipe fittings.
FNPT Female Nominal Pipe Thread. This refers to the female pipe thread, in which the threads are on the inner surface of the connection fitting.
Fall/Flow The proper slope or pitch of a pipe for adequate drainage.
Female Fitting A fitting that receives a pipe or fitting. A fitting into which another fitting is inserted.
Female Threads Faucet threads that are in place on the inside surface of a fitting.
Ferrule Metal cover piece for the lavatory overflow opening. Also used as a reinforcement insert when connecting plastic pipes to prevent compression of the pipe when it enters the fittings.
Fitting Any pipe part used to join together two sections of pipe, such as elbows, couplings, bushings, bends, wyes, tees, etc.
Flex Coupling Rubber coupling used to join DWV Pipe. Can be used to connect PVC and ABS to each other to Clay or Cast Iron above or below ground. Also used for repairs, and attached by used of steel band clamps.
Flexible Connector A braided hose that connects a faucet or toilet to the water supply stop valve. Serves as a riser but is more flexible and easier to install. Usually stainless steel or PVC/Polyester reinforced hose.
Float Ball The floating ball connected to the ball-cock inside the tank that rises or falls with changing water levels in the tank, and actuates or shuts off the ball-cock as needed. Also used to operate a pump, as in a sump pump, according to the water level in the sump.
Floor Drain Drainage fitting that sits flush with the floor, used in basements and showers.
Flow Control Valve Device designed to reduce water flow to a plumbing fixture. Often used to improve efficiency and reduce operating costs. Also a check valve that prevents flow reversal when heater is turned off.
Flow Rate Rated in gallons per minute (GPM) or in gallons per hour (GPH)
Flux Paste applied to copper pipes and fittings before soldering to help the fusion process and prevent oxidation.
Foot Valve A special type of check valve located at the bottom end of the suction pipe on a pump; it opens when the pump operates to allow water to enter the suction pipe, but closes when the pump shuts off to prevent water from flowing out.
French Drain A covered ditch containing a layer of fitted or loose stone or other pervious material.
Friction Head Difference The difference in head required to move a mass of fluid from one position to another at a certain flow rate within a piping system. It is also the specific energy required to overcome friction in the system.
Friction Loss The loss of pressure caused by the turbulence created in water while traveling through the pipe.
Frost Line The depth to which frost penetrates the earth.
GFCI Ground Fault Circuit Interrupter. A device to cut off the flow of electricity if a short circuit is detected.
GPH Gallons Per Hour. A measure of flow rates.
GPM Gallons Per Minute. The rate of flow by which faucets and showerheads are measured and regulated.
Galvanic Action The phenomenon of corrosion of an anode (positive terminal - like on a battery). When two dissimilar metals are immersed in an electrolyte, an electrical potential will exist between them. If the two are in an electrical contact, a current will flow. The metal that becomes the anode (negative) of this cell will corrode and dissolve while the cathode (positive) will be protected from corrosion.
Gauge (gage) Device for registering water level, discharge, velocity, pressure, etc. A number that defines the thickness of the sheet used to make steel pipe. The larger the number, the thinner the pipe wall.
Globe Valve A gate valve with a curved chamber.
Gray Water Waste water from sinks, showers, and bathtubs, but not toilets.
Ground Water Naturally occurring water rising from the water table of the surrounding land.
Grounding Connecting a piece of electrical equipment to a "ground wire" which is connected to the electrical system ground at the 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.
Hanger A device used to support pipes.
Hard Water 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.
Hardness The amount of dissolved minerals in water measured in grains per gallon (GPG). The most common minerals are calcium and magnesium.
Head The pressure of water (or steam) in a closed system (see Pressure Head). It represents the differential in the gravitational force exerted by a liquid at two different depths.
Head Loss The pressure of water as measured at a stated point, either in feet or in pounds per square inch (PSI).
Hose Bibb An outdoor faucet, also used to supply washing machines. Often referred to as a sill cock.
Hydraulic Pressure Pressure that exists in a system containing non-compressible liquid.
Hydrostatic Pressure Pressure exerted by or existing within a liquid at rest with respect to adjacent bodies. Usually refers to the water pressing inward against walls, foundations,floors, etc.
ID Inside diameter. All pipes are sized according to their inside diameter.
IPS Iron Pipe Size (OD). Same NPS. Standard pipe threads. Also Internal Pipe Swivel connection (female)
Impeller Rotating wheel with vanes found inside a centrifugal pump. As it spins at high speed it draws fluids in and thrusts them under pressure to the discharge outlet.
Inlet An entrance, opening, or aperture for the intake of fluid or gas.
Island Vent An air admittance valve.
Integral Vacuum Breaker A device typically used in a sink or shower sprayer to keep water from back-flowing into the fresh water supply.
Jet An orifice or other feature of a toilet that is designed to direct water into the trapway quickly to start the siphon action.
"L" Tubing An industry standard for copper tubing defined by the tube wall thickness and identified by a "blue" strip. Type "L" copper tube wall is approximately 50% greater thickness than Type "M".
Laundry Tray Laundry Tub
Laundry Tub Very deep sink used in a laundry room for soaking or washing clothing.
"M" Tubing An industry standard for copper tubing defined by the tube wall thickness, identified by a "red" stripe.
MIPC Male Iron Pipe Connection. Standard external threads on pipe and fittings.
MNPT Refers to the male pipe thread, in which the threads are on the outer side on the connection fitting.
Macerator A device installed in a drain line between a toilet and the soil stack to reduce solids to liquid form.
Main 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.
Male Fitting Fitting that is inserted into another fitting.
Non-Potable Not suitable for drinking.
O-Ring Round rubber washer used to create a watertight seal, chiefly around valve stems.
OD Outside Diameter
Orifice An opening through which gas is discharged and whereby the flow of gas is limited and/or controlled.
Outlet/Discharge The opening through which the water exits the pump.
Outside Diameter The diameter of a pipe measured from the outside edge. (OD)
PEX Cross-linked polyethylene. PEX tubing is commonly used for hydronic radiant floor heat, but increasingly also used for water supply lines. Stronger than PE.
PHCCA Plumbing Heating Cooling Contractors Association
PSI Pounds per Square Inch
PVC Polyvinyl Chloride. A rigid white or cream-colored plastic pipe used in non-pressure systems, such as drainage, waste, and vent systems.
Perforated Pipe Pipe designed to discharge water through small, multiple, closely spaced orifices or nozzles, placed in a segment of its circumference for irrigation purposes
Pipe Dope Industry term for pipe-joint compound. Substance applied to threaded fittings to create a watertight seal.
Pitch Downward slope of a drain pipe in the direction of the water flow.
Plug Male threaded fitting which seals the end run of a pipe when fitted into a female threaded fitting.
Plumb Precisely vertical. Also to test for, or to make vertical. Also to perform plumbing work.
Poppet Valve that rises perpendicularly to or from its seat.
Potable Water Water that is suitable for drinking.
Pressure Head Pressure in a plumbing system. The unit of measure which is the vertical force exerted by water at a depth of one foot.
Pressure Loss The term given for the of pressure that occurs whenever water moves through a pipe or when water moves uphill against the force of gravity. If the total pressure loss in a piping system exceeds the available static water pressure the water will not flow.
Pressure Reducing Valve A valve that automatically reduces inlet water pressure to a specified value at its outlet under static cold water conditions.
Pressure Regulator A device for controlling and maintaining a uniform outlet gas pressure.
Pumping Level The lowest water level reached during pumping operation.
Red Water Water which has a reddish or brownish appearance due to the presence of precipitated iron and/or iron bacteria.
Reducer A fitting that connects pipes of different sizes together.
Saddle Tee Fitting that taps into the side of a pipe, used to make quick connection to an existing line.
Saddle Valve A valve mounted on a pipe run by a clamping device, or saddle tee to provide a water supply for a low-demand device.
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.
Sanitary Sewer House drain that carries wastewater away from the house to a sewer system or septic tank.
Scale A thin coating or layer, usually calcium on the bottom of a tank or interior parts that may prevent heat transfer.
Schedule Numbers assigned to different wall thicknesses of pipe (e.g. sch 40).
Sediment The substance that settles on the bottom of a water tank. Also known as lime.
Service Entrance Pipe connecting the water company piping to the water meter.
Service Pressure The range of pressure in the pressure tank during the pumping cycle, usually expressed in pounds per square inch gauge (P.S.I.G.).
Shutoff Valve Usually refers to angle stops installed under sinks and toilets, but also valves installed on branch lines and alongside the meter.
Sill Cock See Hose Bibb
Siphon Break The point in a toilet flush cycle when air is re-introduced into the trapway, breaking the siphonic action. This is characterized by the deep gurgling sound heard at the end of a flush.
Siphoning The suction or pulling effect that takes place in the trapway of a toilet as it is filled with outgoing water and waste.
Solder A metal alloy that is melted to create a fused joint between metal pieces. Also the act of melting solder into the joint.
Solvent Weld Any of the types of PVC pipe and fittings that are fastened together with solvent-based cement.
Spigot The plain end of a cast-iron pipe. The spigot is inserted into the bell end of the next pipe to make a water tight joint. Also used as a term for the end of PVC pipes and fittings that are inserted into the larger socket part of the next fitting.
Static Discharge Head The vertical distance from the pump to the highest outlet in the water system Stand By Loss. The amount of heat lost while a unit is in stand by mode.
Static Lift The vertical distance between source and discharge water levels in a pump installation.
Static Pressure The pressure when no water is flowing.
Static Water Level The undisturbed level of water in the well before pumping.
Submergence The distance the ejector, foot valve or submersible pump is installed below the pumping level.
Suction Head The head on the suction side of the pump. This is subtracted from the discharge head to determine the head being produced by the pump. It is a sum of the static, pressure and friction heads.
Suction Static Lift Same as Suction Static head. This term is only used when the pump centerline is above the suction tank fluid surface.
Sump A pit or pool for draining, collecting, or storing water. A chamber which provides water to the pump.
Supply Kit Usually a kit of all parts needed to connect a faucet or toilet to the pipes coming out of the wall. Usually includes stop valves, water connectors, and escutcheons.
Surface Pump A mechanism for removing water or wastewater from a sump or wet well.
Sweating Term for soldering. Also formation of condensation on the outside of pipes or toilet tanks.
Tee T-shaped fitting with three openings that allow another pipe to be joined at a 90 degree angle, used to create branch lines.
Teflon Tape A fluorocarbon polymer with non-sticking properties used to wrap pipe threads to seal a joint.
Threaded A helical or spiral ridge on a screw, nut, or bolt.
Total Discharge Head The total pressure or head the pump must develop. It is the sum of the depth to pumping level, elevation, service pressure, and friction loss.
Turbulent Flow Fluid flow in which the velocity at a given point varies erratically in magnitude and direction. Turbidity Water cloudiness caused by suspended particles.
Union Three piece fitting that joins two sections of pipe, but allows them to be disconnected without cutting the pipe. Used primarily with steel pipe; never in a DWV system.
Universal Plumping Code A system of procedures designed to provide consumers with safe and sanitary plumbing systems and used throughout the United States by local jurisdictions.
Vacuum Breaker An anti-siphon device that prevents the backflow of contaminated water into the water supply system.
Valve A device that regulates the flow of fluid.
Valve Seat The non-moving part of a valve. Water flow is stopped when the moveable portion of the valve comes in contact with the valve seat.
Venturi 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 a suction in a vacuum pump.
Wall Thickness The thickness of the tubing wall.
Water Hammer A loud banging noise caused by the hydraulic shock of suddenly shutting off a water supply.
Water Hammer Arrestor A fixture to absorb the hydraulic shock caused by a sudden shutoff of water.
Wye A Y-shaped fitting used to create three branch lines. Allows one pipe to be joined to another at a 45 degree angle to continue on as one pipe.