All Plumbing Terminology

All Plumbing Terminology

Delve into our list of plumbing terminology to make your way in this complex yet necessary market. This article will make it easy for you to understand the core concepts that stand at the foundation of the plumbing world. Let’s begin!

ABS – Acrylonitrile-butadiene-styrene. Rigid black plastic pipe used for Drain, waste, and vent lines. Please check your local codes to see if this material is code approved. In most major metropolitan areas it is not a code approved material.

ABS Pipe and Fittings

ABS Pipe and Fittings

Absorbent – A material that is used to hold gases, liquids or solids or suspended solids on it’s surface or inside pores. The most common absorbent used in the plumbing world is activated carbon.

Absorption Field – This is a seeping field designed to disperse the liquid waste from a septic tank through a filter bed. The septic tank fills with liquid and solid waste and the liquid waste drains off to the absorption field leaving the solid waste behind.

Absorption Pit – A pit specifically designed to disperse liquid waste from a septic tank through a filter bed.

Access Panel -A covered opening in wall made near a plumbing or electrical fixture to allow access for maintenance. In plumbing an access panel would hide control or shut off valves or cleaouts for rodding plumbing fixtures.


Paintable Access Panel

Acid Dilution Basin – A plumbing appurtenance connected to waste piping servicing a part of a building receiving corrosive or acid waste. Most acid neutralizing basins use limestone as the neutralizing media. Here are some applications where an acid dilution should be used, school labs, hospitals, research facilities, pharmaceutical manufacturing, printing facilities, automotive service centers, film processing, etc.

Acid Waste – Any waste water containing corrosives or acidic liquids that must be neutralized before entering the municipal sewer system. Most often fixtures receiving acid waste are connected to an acid dilution basin which neutralizes acid before the waste water enters the sewer.


Orion Acid Waste Products

Acid Waste Piping – Simply put its waste piping and fittings that are resistant to acid waste. Examples of applications where this is used, laboratories, hospitals, photo labs and printing presses. Some of the materials used in making acid resistant pipe and fittings; glass, polypropylene and polyvinylidene fluoride for really harsh situations. Polyvinylidene fluoride is also fire retardant and when approved can be used in a plenum ceiling.

Acrylic – A very strong and hard thermoplastic and in plumbing it is used as a surface material for bathtubs, shower bases, tub or shower surrounds. When used in bathtubs and showers acrylic is usually back with fiberglass to add strength and rigidity.  Acrylic is also used to make plexiglass shower doors.

Activated Sludge – Waste that contains the solids that have settled during final sedimentation after waste is aerated.

ADA – (Americans with Disabilities Act) This term is very important as it relates to plumbing. It affects the height that water closets can be mounted, the types of handles you can install on a lavatory faucet, how much pressure it takes to push down a flush valve handle and those are just a few. Here is a link to the 2010 ADA Standards publication


Sweat Copper x MIP Adapter

Adaptor – A fitting used to join dissimilar piping methods i.e. sweat copper to threaded fittings, PVC to cast iron.

Adjusting Linkage – An adjustable rod or strap that forms the connection between the lift rod and the ball lever assembly of the drain.

Aeration – a method to introduce air with water to help in releasing dissolved gasses that contribute to foul odors or unpleasant taste. Aeration can be done in several different ways, air can be bubbled up through the liquid, liquid can be sprayed into the air or the liquid can be agitated oxygenating it by bringing the surface water in to contact with the air. The best example we can give for the use and effects of aeration is the cleansing of the Calumet Sag River in Illinois. Large parks where created along the Calumet Sag River pumping millions of gallons of water through attractively created waterfalls. The results have been staggering.

Aerator Fittings – a type of fitting installed on a plumbing fixture that mixes water with air. These fittings help with water conservation and reduce splashing.


Faucet Aerator Fitting

Aerobic Bacteria – Bacteria living, active and occurring in the presence of oxygen.

AGA – (American Gas Association)

A.I.A -(American Institute of Architects) This is basically a self policing regulating body that promotes excellence in architecture. They are heavily involved in all facets of education for their members from internship, to mentoring to licensing and support. A.I.A. is also the preferred method by which sub contractors invoice their customers. Chances are if you’ve been a subcontractor for awhile you know exactly what G701, G702 and a G703 form is for. If you are familiar with all of the AIA forms are you probably have a head ache, they can be tedious but they are ultimately there to protect the Owner.

Studor Vent

Studor Air Admittance Valve

Air Admittance Valve – The most common of these is called a STUDOR vent, these valves are designed to allow air into a drainage system with out using a vent. It opens to allow air to equalize pressure in the drainage system but closes to stop sewer odors and gases into the living space.

Air Chamber -A vertical air filled pipe or manufactured spring coil installed above the waterline in a potable water system that absorbs pressure fluctuations when valves are turned off i.e. a shower is turned off or a fill valve in a toilet slams shut. The pressure absorbing devices reduce water hammer. Having air chambers on plumbing fixtures with water connections is code for most municipalities.

Typical Shower Air Gaps

Typical Shower Air Gaps

Air Gap –   The unobstructed physical distance between the outlet end of a  plumbing apparatus or piping delivering potable water to a plumbing fixture to the flood rim level of the receptacle (sink, dishwasher, clothes washer or tank) Think of a kitchen sink faucet with a pullout spray if you pulled it out and laid it in the sink you would have no air gap. The air gap protects the potable water system from cross contamination. Please see Backflow Prevention Device, Vacuum breaker, double detector check valves.

Common Air Gap on Lavatory Fixture

Air Gap on a Lavatory

All Thread Rod – a connecting rod used in almost every construction trade. In the mechanical trades it is mostly used to hang piping materials from the underside of a the structure of the building.. Threads are in one direction and standard hex nuts can easily be screwed on to secure a multitude of different hangers. Come in a variety of sizes and finishes. Most common sizes in the piping trades are 1/4″, 3/8″,1/2″,  5/8 & 3/4″ it’s most common finishes are black and galvanized, stainless steel is also a common material.

Anaerobic Bacteria – Bacteria that lives and grows in the absence of free oxygen. These bacteria get their oxygen by decomposing substances that contain oxygen.

Angle Stop or Angle Valve – Angle stops are named because they are manufactured at a 90degree angle, they are used as shut off valves at the water intake of plumbing fixtures or appliances. They usually have an oval handle or can have a removable handle when vandalism or theft is an issue. They are not meant to be used in high pressure situations.

Angle Stop - Typical Two Way Angle Stop

Common Angle Stop

Angle of Repose – This is one of the first things we learned about excavating in plumbing school. The lesson was followed by a video of a man caught in a cave in. He broke most of the bones in his body amongst other gruesome things. This is the greatest angle above ground level at which backfill or debris will lie without sliding. Please use shoring figure out the angle of repose if you’re digging below 4ft.

ANSI – (American National Standards Institute) The American National Standards Institute was founded in 1918 and they are the U.S. voice for conformity and regulation. ANSI is compromised of government agencies, academic institutions, manufacturers and contractors and their purpose is to enhance the US global position and to create regulations, norms and guidelines. Those regulations affect almost all businesses from every sector.

Anti Microbial (plumbing definition) – Any plumbing fixture or plumbing accessory that is manufactured with anti-microbial characteristics integral to the product. An anti-microbial plumbing product is one that kills or hinders the growth of bacteria, mold, etc. Vitreous china is naturally anti-microbial when glazed because of it’s glazing and non porous surface. Recently toilet seats are a common plumbing accessory manufactured with anti-microbial  properties.

Anti-scald Valve – (please see pressure balanced and thermostatic mixing valve)

Americast – A patented process from American Standard that uses a porcelain surface, an enameling grade steel material and a structural composite backing bonded together to create a sink that is similar to cast iron in durability, heat retention and sound deadening but weighs considerably less therefore it is cheaper to install.

Annealing – In plumbing the process by which rigid copper is made soft and pliable. The process consists of heating the metal to a certain temperature and holding that temperature for a set amount of time then allowing the metal to cool slowly to room temperature.

Anode Rod –  These sacrificial anode rods are installed at the top of a water heater tank and are generally made of magnesium or aluminum with a steel core. Simply put, through electrolysis the anode rods will corrode before the exposed metal in the tank. If the anode rod has been corroded the water begins to attack the exposed metals in your water heater which will eventually cause it to fail.

Anti-Siphon Valve (Vacuum Breaker) – The simple definition is an anti-siphon valve is a device installed on a water supply line that prevents water from backing up into the potable water system. Vacuum breakers are an example of an anti-siphon valve. Anti-siphon valve are most commonly spring loaded one way valves. When the direction of flow is going in desired direction all works well, if the direction of liquid changes the valve slams shut prevent back siphonage.

Vacuum Breaker

Vacuum Breaker​

Apron (or Skirt) – The decorative portion of a bathtub that covers the rough-in area of the tub. It is most easily recognized on a whirlpool tub, the apron is most often removable to be able to service the tubs plumbing and or motor.

bathtub apron

Bathtub Apron

ASA – (American Supply Association) Formally founded in December of 1969 the ASA is an organization that represents wholesale distributor and their supplier in the plumbing, heating, cooling, industrial and mechanical pipe, valve and fittings industries.

ASME – (American Society of Mechanical Engineers) A professional member ship group founded in 1890, this group originally came together to test steam vessels because of the numerous failures. Now it is the premiere standards development organization. Setting codes and standards throughout the mechanical trades.

ASSE- (American Society of Sanitary Engineering) Founded in 1906 by Henry Davis Chief Plumbing Inspector for the District of Columbia. This group consisted of plumbing engineers, plumbing inspectors and installers all with the common idea of making plumbing safer and more universal though out the United States. They also have quite a bit of influence as to the adoption of plumbing code and the vital testing of plumbing product and theory.

ASTM International – (formerly know as American Society for Testing Materials) Formed in 1898 by chemists and engineers from the Pennsylvania Railroad they organized the railroad’s new chemistry department, where they investigated the technical properties of oil, paint, steel, and other materials the Pennsylvania Railroad bought in large quantities. Organized a new set of standard that they expected their suppliers to follow. At the present they are “globally recognized leaders in the development and delivery of international voluntary consensus standards” Please visit their web site for a more detailed history.

Back Flow – The circumstance of water traveling from one system back into any part of the main distribution system, usually by siphoning.

Back Flow Preventer – The two most common types of back flow prevention devices are a double detector check assembly and an RPZ. A double detector check assembly is one device that houses two check valve assemblies in the line of flow. The check valves are spring actuated and are designed to open with 1 pound of pressure.

The double detector check assembly is installed with one (1) gate valve on the inlet of the valve and one (1) gate valve on the outlet side of the valve. These assemblies prevent back flow or back pressure in nonhazardous situations and are most used to protect the potable water system of a building from the water in a fire prevention system.

A detector check is made with a by-pass assembly and meter to detect any unauthorized or illegal taps, test cocks are also present so that required yearly testing can take place. Each check valve can be isolated and tested independently to see if they are leaking and operating properly.

An RPZ – is very similar to the double detector check in that it houses two testable check valves. It has two gate valves one (1) on the inlet and one (1) on the outlet. Here is where things change, an RPZ is used in high hazard situations, where contamination of the water supply would pose a significant health hazard.RPZ (reduced pressure zone backflow preventer) and Double Detector Check Valve

Backpressure in a Plumbing System – Pressure that is less than atmospheric pressure. If a sewer drain line is running at 100% capacity and with greater than intended velocity if the waste water passes another drain outlet it could cause a negative pressure. This negative pressure can pull a water seal from a trap causing sewer gas or vermin into the living space. Extremely high winds can also pull the air from the plumbing vent pulling the trap seals with it.

Backup (Sewer) – The overflow of water usually combined with waste from a plumbing fixture caused by a blockage in the fixture drain or waste line servicing the aforementioned plumbing fixture.

Battery Back-up System

Battery Back-up System

Back-up Sump Pumps – Literally any pumping device that acts to back-up the primary sump in case of power failure or primary pump failure. Most  back-up sump devices include some sort of marine battery either wet cell or maintenance free gel battery. There are back-up sump pumps that use no electricity and function on incoming water pressure.

Backwash Cycle – No this isn’t what you’re sibling leaves in the bottom of the Gatorade bottle. The Backwash cycle is a process a water softener or water filter goes into, usually pre-programmed for off hours, whereby the water flow is reversed cleaning the filter media. The waste water is sent to an open site drain.

Backwater Valve – A valve that is installed on the house sewer that prevents water from backing up into the house. The most common use for a backwater valve is in situations where the city sewer is combined waste and storm. In these cases during torrential rain the city sewer runs full with only one place to go, back into the house or businesses connected to it, a backwater valve is installed in this situation.

Baffle – An object or screen placed in a plumbing fixture or appurtenance to change the direction of or retard the flow of water or flue gasses. The most common baffles used in plumbing are the ones found in a grease separator. The baffles are used to slow down the incoming waste water, allowed the suspended grease and solids to cool and rise to the top for easy removal.

Balancing Cocks or Valves A valve with an adjustable partition or gate which can be used to increase or decrease flow. They also have self sealing ports in which thermometers can be inserted to check the temperatures of the liquids.

Ball Cock – The valve by which the water enters a tank type toilet (water closet), fills the tank and shuts the flow of water off when the water reaches a predetermined height in the tank.

Barrier Free – This relates to ADA and handicap access, the easiest to understand is the barrier free shower base. A barrier free shower base has little or no threshold to encumber a wheelchair from entering or exiting.

Basin Wrench – Is a tool that only has one real use , it’s inexpensive and pretty easy to use. A basin wrench actually looks like a steel bar with a curved head with teeth on one end. The other end ends with a T handle. Obviously turn the water off before using. Go under the sink and position the head at a 90 angle catching the nut, turn in the appropriate direction to remove and your all set. If the sink faucet is too high to reach you may have to pull out the extended handle.

Basket Strainer – A device shaped like a cup or a basket with holes or slots that fits inside a drain that allows water to drain out but catches debris before it enters the waste piping.

Beam Clamps – A clamping device used when beams are the only thing used for support. They are used in conjunction with pipe hangers to ensure proper support and pitch. The beam can be c-clamp type or can span the entire beam.

Bench Mark – It is a known elevation set throughout a building or job site that all trades can use to locate proper elevations for doors, windows, plumbing fixtures etc. An elevation will be set usually by the general contractor in accordance with the engineer and all trades can measure from that elevation.  It can also be a mark on a permanent flat service whereby it is used to lay out walls, columns, stairwells, etc.

Bends – A generic term given to all elbows made from all types of piping material.

Bidets– A plumbing fixture about the same height as a seat of a chair that is most often used for the bathing of the external genitals and the posterior parts of the body.

Biodegradable – Any material subject to degradation to simpler substances by way of biological action i.e. aerobic and anaerobic decomposition. Substances that are considered biodegradable are detergents, human waste, organic matter.

Black Water – Waste water from toilet, urinals, bidets or food prep receptacles or waste water from drains receiving chemical waste.

Bleed (Water System) – To drain a pipe or piping system of excess air by opening plumbing valves or appurtenances exposed to the atmosphere i.e. shower valves, faucets and drain down valve.

Blind Plug – A plug or cap used on no-hub piping to end a drain line. It is affixed to the end of the pipe by a no-hub coupling.

BOCA CODE – (Building Officials Code Administrators International)

Body Sprays – For all practical purposes these are shower heads.  Some are hand held, some are on a sliding bar so that the can be moved up or down and some are positioned throughout a shower to spray on different parts of your body while showering.

Body Spray Tiles

Body Spray Tiles

BoilersSee PlumbingMechanical Equipment

Brackish Water – Any water containing bacteria between 1,000 and 15,000 ppm of dissolved solids.

Braided Supplies – A flexible pressure tubing usually made of synthetic material that is encased in braided threads of steel or stainless steel. The braided covering protects the synthetic tubing from damage due to abrasions and crimping.

Branch Vent – A vent connecting one or more individual vents with the vent stack.

Branch Water Piping – The local domestic water piping that extends from the vertical risers (or other mains) and supplies water to plumbing fixtures or equipment.

Brass Seats and Seals – In a plumbing valve the surface area on the moving part of a valve and the stationary part of the valve. When the moving part of the valve comes in contact with the non-moving part the flow of water stops completely. The most common material used for valves seats is brass. Brass seats eventually have to be repaired or replaced because with continual use the seating surface degrades over time.

Brazing – uses (How To) Similar to soldering, brazing is the process of filling a void (for plumbing) in a pipe joint with a filler metal to join pieces of pipe or fittings. Brazing filler metals generally have melting temperatures above 1,100 degrees Fahrenheit. Most brazing filler metals contain some amount of silver, copper and phosphorus.

Break Tank – A type of vessel that holds a supply of water that is to be used for a specific purpose (mainly heating) other than for consuming or flushing plumbing fixtures.  It is filled through an air gap (to prevent contamination of the domestic water system) and the water supplying the tank shuts off, when filed to a predetermined height, by an automatic shut off valve.

Bubbler – The word bubbler has a rather interesting back story. It’s definition is simple, it’s another word to describe a drinking fountain like the ones you see at a park. However, there is really only one place in the country where it is used with regularity and it’s in the Badger State of Wisconsin. Check out this article for more on this strange little regional phenomenon.

Building Drain – The lowest point of a drainage system where all of the interior drainage piping meets and is discharged into the sewer.

Bushing – A pipe fitting used to join two pieces of dissimilar sized piping. There are many different joining methods but the most frequently used is threaded on both ends.

Butterfly Valves – The butterfly valve has some similar features to that of the wafer check valve. It is very thin and lightweight so space and support are not issues. It is closed using a wafer or disc that is mounted on a rod that is secured in the middle of the valve. The rod exits the valve at the top and ends with a handle that incrementally controls the internal disc. In the open position the disc is parallel to the pipe in the closed position the disc is perpendicular to the pipe closing off flow. These types of valves can be used to control flow and are especially affective in tight spots. Most times the handles are spring loaded and allow you to lock the valve into a certain position.

Nibco Butterfly Valve

Nibco Butterfly Valve

CAD (Computer Aided Design) – A method of designing building mechanical systems using a well known computer software. Prior to CAD, engineers and architects had to design and layout all of the different piping trades by hand and with the aid of the subcontractors “shop drawings”. Now most of it’s done via computer. There are still changes in the field but those changes are always relayed to the engineer and are updated on the master CAD files.

Cast Iron Pipe and Fittings – Plumbing sewer and vent pipe and fittings that are made from cast iron.  It is manufactured in two (2) types–hub and spigot, and no-hub.  The hub and spigot pipe and fittings are manufactured as either service weight or extra heavy.  This relates to the wall thickness of the pipe and fittings, the extra heavy having a thicker wall thickness.  The extra heavy pipe and fittings are rarely used today and availability of various fittings is limited.

The hub and spigot type pipe is manufacture in three (3) lengths–five (5) and ten (10) foot single hub, five (5) double hub and thirty (30) inch double hub.  Single hub means the pipe has one (1) end that is plain and the other has a hub and double hub means there are hubs on both ends.  The no-hub pipe and fittings are manufactured in service weight and the pipe only comes in (10) foot lengths. The hub and spigot pipe and fittings are joined by using either neoprene gaskets or lead and oakum.  The no-hub pipe and fittings are joined by using a stainless steel band with neoprene gasket that is manufactured specifically for the no-hub pipe.

Charlottte Cast Iron Fitting

Cast Iron Waste Fitting

Ceramic Discs – similar to brass seating material, ceramic is the hardest material you can use in seating material. One ceramic disc rotates and slides against the other. As the holes or notches in the discs align the water passes through. Ceramic discs are completely unaffected by water temperature so the neither expand nor contract, they are not damaged by debris in the water line.

Chair Carrier – (Please see Fixture Carrier)

Check Valves – A check valve is a one way valve in that is has one inlet and one outlet that allows the a liquid to travel in one direction. It is used to halt the flow of the aforementioned liquid in case of a drop in pressure or reverse in directional flow. The majority of check valves used in the plumbing industry work automatically meaning when the pressure or direction changes the valve slams shut.

Brass Nibco Check Valve

Brass Nibco Check Valve

Circuit Setter -A circuit setter is a balancing type valve used in an HVAC or plumbing system to regulate pressure in the whole system or within part of the system. In a plumbing system it is used to regulated pressure between hot and cold water inside the potable water system. Many years ago a check valve and a ball valve where used, the check valve would shut down a hot or cold water supply if there was a sudden drop in pressure and the ball valve with a memory stop was used to regulate flow. This prevented cold or hot water bleed over if the pressure was increased or decreased in either supply piping.

Circuit Vent – A branch vent that serves two or more fixtures with integral traps like a water closet or fixtures with p-traps installed in a battery (fixtures grouped together). The vent extends from the top of the horizontal waste branch in front of the last fixture waste to the main vent stack of a building drainage system.

Cleanout – An accessible opening that is placed in a drainage line  at a convenient location to accommodate drain cleaning equipment in the event of a line blockage.

Cleanout CoverAn esthetically pleasing cover (usually chrome plated) that hides a cleanout. The cleanout cover is usually furnishing with a chrome center screw that threads into the cleanout plug.

Cleanout Cover

Chrome Cleanout Cover

Clevis Hangers – A piece of metal bent in the shape of a “U” that is used to support pipe or conduit from a structure. The “U” has holes through both ends through which a rod is inserted and attached to the rod is a yoke with a hole in it through which a threaded rod is inserted and the threaded rod is attached to the structure.

Closet Flanges – A flanged fitting that is connected to the sanitary drainage system that is used to bolt a water closet (toilet) to the floor. They are made of different materials, i.e., cast iron, copper and PVC.

Cock Hole Cover – We know it’s a silly word but it is an actual plumbing term. It is simply this, a metal cover that is inserted onto an empty hole in your kitchen sink or counter top. They come in different finishes like chrome, brass, white and stainless steel. Say you replace your old kitchen sink faucet that has a side spray with an updated model that has a pull out spout. The faucet with the side spray used a four hole sink.  The one with a pull spout uses three holes or one if you don’t use a cover plate, you’ll have one extra hole. You’ll need the ever famous cock hole cover.

Coffee Station – In a commercial tenant space, a place for employees to get coffee, ice, or have lunch or take a break. Coffee stations typically consist of a kitchen sink, faucet, coffee maker, and refrigerator. Depending on the municipality the coffee station may require a grease interceptor and a floor drain. The coffee maker and the refrigerator will require a backflow preventer.

Cold Chisel – A steel hardened tool that is manufactured in various lengths and diameters with a beveled end that is used for chipping and breaking concrete, cast iron, steel and other hard material.

Combined or Combination Sewer – piping that is designed to carry both rain water with sewage. This method of evacuating waste water is being phased out around the country in favor separating the storm sewer from waste.

Composite Material – A material used to manufacture counter tops and and sinks. Composite materials usually have an acrylic base that is colored and different aggregate materials are introduced to give the surface a unique look and in some instances adds strength. Quartz composite sinks are a great example of composite material were quartz is added to give it a unique look and adds strength and resists corroding and chipping.

Compression Fittings – 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. 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.

Copper Pipe and Fittings Copper pipe and fittings are material used in drainage, waste and vent pipe as well as potable water piping. Copper is fairly easy to work with, has excellent thermal conductive properties and it is very durable. Copper comes in a wide variety of pipe sizes and can handle water, oil and gas.

Core Toilet Rooms – A group of centrally located toilet rooms in a commercial, industrial or institutional building. These toilet rooms are usually designed to accommodate a certain number of workers or guests per floor or per area of a building. If core toilet rooms are in a multi-level building they are usually stacked on top of one another using a common wet column.

CPVC – (Chlorinated Polyethylene) – This is PVC plastic piping infused with chlorine to increase it’s temperature rating. It also improves its fire rating as well.

Cross Connection – Any connection in plumbing that allows potable water to be connected to a non potable water source. Cross connections can be a potentially serious health hazard. Here is an example of a cross connection : a good number of utility sink faucets come with a threaded hose connection at the end of the spout. This is used to attach a hose so a floor or room can be washed down. If the spout or faucet is not installed with a vacuum breaker and the hose is dropped into the utility sink filled with water and a cleaning chemical you have a cross connection.

Dip Tubes – Usually a plastic tube that is inserted into the inlet side of a domestic water heater.  The tube forces the incoming water to the bottom of the heater, (closest to the heating elements) whereby the water is more evenly heated throughout the tank.

Dishwasher Air Gap – An apparatus that is usually mounted next to your faucet, either on the counter or in a knockout on the kitchen sink. This device connects from the waste outlet of the dishwasher to the airgap and from there it connects to a waste opening in the p-trap of the kitchen sink. It allows waste water to flow into the waste piping however of the waste piping should ever back up, the waste water will not back up into the dishwasher because of the aforementioned air gap.  Please see our diagram for further clarification.

Dishwasher Air Gap Blow Up

Dishwasher Air Gap Blow Up

Double Detector Check Valve – The double detector check assembly is installed with one (1) gate valve on the inlet of the valve and one (1) gate valve on the outlet side of the valve. These assemblies prevent back flow or back pressure in nonhazardous situations and are most used to protect the potable water system of a building from the water in a fire prevention system.

A detector check is made with a by-pass assembly and meter to detect any unauthorized or illegal taps, test cocks are also present so that required yearly testing can take place. Each check valve can be isolated and tested independently to see if they are leaking and operating properly.

Downspout Piping – Also known as storm water piping.  It is the piping system that handles the discharge of rain and melted snow water to the city sewers, retention ponds, or ground level pavement or grassy areas.  On the interior of buildings the piping material is usually made of cast iron, copper or PVC.  When it is installed on the exterior of the building the piping material is usually sheet metal like the downspouts on a private residence.

Drain Piping Pitch
(Slope) – In plumbing the grade at which the drain piping is installed to assure that the waste water flows at a speed that allows the piping to be self scouring. Meaning the turbulence and movement of the water cleans the inside of the pipe. 1/4″ per foot is a common pitch for plumbing. We like to say a lazy sewer is a good sewer, if the water is moving too fast it may move past the suspended solids leaving them behind. If enough waste is left behind you have the potential for a build up and an eventual blockage.

Drain Tile System – A system of pipe usually made of corrugated plastic, PVC or clay tile that collects subsoil drainage and allows it to dump into a sewer or water retention area. Drain tile is usually perforated to allow water to seep into the pipe and it is widely used under basement floors or under concrete footings, this keeps water from getting into basements or washing out backfilled soil. Drain tile is also used in athletic fields, farm fields and in any situations where water needs to be removed quickly.

Drainage Fittings (Cast Iron) – This a true plumbing professional term. Obviously all Drainage, Waste and Vent (DWV) are types of fittings used for drainage however cast iron drainage fittings are threaded fittings that are specifically used for drainage piping. These fittings are a dying breed and are only used in certain areas or in repair situations. These fittings are made with pitch built in to assure proper flow. Anvil Corp is one of the last companies to continue making CI drainage fittings. You can find them here.

Drop in Bath Tub – A bathtub that is built with an integral lip or ledge that is meant to fit into or be dropped-into a pre-framed area that is to receive the bathtub.

Kohler "Devonshire" Drop In Bathtub

Kohler “Devonshire” Drop In Bathtub

Drop-in Anchor – These are anchors that are inserted into a pre-drilled hole in concrete. The anchor has a metal cam inside that when hit or “set” flares the bottom out to secure it in the concrete. Drop-in anchors are threaded on the inside to accept all thread rod or bolts and they are commonly used in conjunction with a clevis hanger to hang piping from the underside of a deck.

Drum Traps – Very rarely used, a drum trap is a circular metal canister with the inlet near the bottom of the trap and the waste outlet is at the top with a removable cover. Ideally the drum trap is installed in a place with easy access so you can remove the cover to clean. Unfortunately many drum traps we’ve encountered are buried behind a wall or the cover is unable to be removed, fused together by time. So when drum trap stop they are extremely difficult to clear by rodding because of their inlet and outlet configuration. Drum traps were installed so people could find jewelry or valuables if lost down the drain. The trap would catch the ring or earring by sinking to the bottom, the likely hood that a valuable would flow into the waste opening at the top of the trap is highly unlikely.

Drum Trap

Duplex Pumps (Ejector or House Pumps) – This is simply a pumping system that uses two pumps instead of one. These pumps are usually equipped with an alternator that alternates pumping cycles to minimize wear on one particular pump. The alternator can be set to alternate the pumps in a variety of ways i.e. every other cycle, every ten cycles or it can be set by usage parameters if equipped with the right controls.

Effluent – Waste material – the waste and/or waste water outflowing from a septic tank.

Ejector Pits – A round, square or rectangular pit (collection vessel) that can be made from cast iron, steel, PVC, fiberglass, concrete or clay tile.  They are used in applications where the sanitary waste that flows into them is lower that the main sewer and by mean of an ejector pump(s) the waste is pumped up and out to the main sewer.  They must always have a gas tight cover and be properly vented.

Ejector Pumps – A device manufactured to elevate water, sewage (suspended solids) or liquid waste from a lower level to a point of discharge where it can be drained away by gravity into a sewer or drain.

Elevated Vacuum Breaker – A vacuum breaker that is elevated off the floor at 7ft-6″. There is a very good reason it is elevated at 7ft-6″ it is above the average height of a man with his arms stretched over his head. Huh? Yep, the reason for this is a person cannot take a hose and stretch to place it above the vacuum breaker rendering the vacuum breaker useless. I know how about we just step on a chair? Whatever…that’s the reason for 7ft-6″. Elevated vacuum breakers are slowly dying.

Classic Chicago Faucet Elevated Vacuum Breaker

Classic Chicago Faucet Elevated Vacuum Breaker

Epoxy Pipe Lining – Epoxy lining of plumbing pipes is used when the cost of digging and or tearing walls and ceilings apart proves to be too cost prohibitive. There are several different types of epoxy pipe lining and they are used based on application type.

  • Air Inversion – Air inversion pipe lining is used in waste, vent, storm and water main to repair broken piping due to ground settling, pipe deterioration, tree roots etc. It is most commonly used in pipe sizing from 4″ to 48″ in diameter. The piping is prepared by video camera inspection, then <the pipe is cleaned and scoured. The pipe is then lined using an air inversion machine. Think of tube sock with epoxy lining on the inside. It is glued on one end and air pressure pushes the sock through the pipe turning it inside out thereby placing the epoxy inside the piping. Please check out this Youtube video that shows you in detail how the process works.
  • Pipe BurstingThe pipe bursting method is used in underground piping i.e. concrete or clay tile where the piping is too deteriorated to repair by other methods. A very strong cable is pulled through deteriorated piping and attached to a conical pipe bursting head, attached behind the head is the new piping. As the pipe bursting head is pulled through the old piping it is being broken up and the new piping is being pulled through the old pipe bed.
  • Epoxy Pipe Restoration – This method is used mostly in water piping and it is most effective in pipe sizes from 1/2″ through 4″. Although some companies have different techniques most have these steps that are common for all. Drain down of water piping being restored, heated and compressed are introduced to the piping to dry pipe thoroughly. A sand slurry mixture is blown into the pipe to scour the inside of the pipe walls, knocking off any scale or oxidation. Finally the epoxy coating is blown in coating the inside of the pipe. Check out the video of CuraFlo explaining the process.

Expansion Tank – A tank usually installed on a closed hot water line used to absorb excess pressure due to thermal expansion. Because water expands when heated, the water needs a place to expand to hence the expansion tank.

Amtrol Expansion Tank

These are code just about everywhere.

Express Riser – A domestic water riser is used to distribute potable water to floor levels that require potable water to function in both commercial or residential applications. For a high rise building maintaining water pressure suitable to proper fixture function is critical. An express riser is a water riser thats sole purpose is to bypass lower floors and service upper floors so adequate water pressure is maintained.

Extension Tailpiece – A length of tubular brass or PVC piping used to extend the waste on a kitchen, lavatory or service sink. Connections or usually Slip Joint or threaded.

Extra Heavy Soil Pipe – Cast iron soil has been used for drainage, waste and vent piping for hundreds of years. Extra heavy soil pipe is specified for extreme conditions and has a very high crush strength. It’s popularity has declined sharply over the last 30 years. It was not uncommon to see extra heavy soil pipe used in schools, hospitals and prisons.

Faucet Types – A faucet is any device that controls the flow of water. The most common types of faucets used in plumbing are kitchen, lavatory, bar, service sink, hose bibbs, shower valve, tub filler and yard hydrants.

Federal Plumbing Code – (Please see National Plumbing Code, BOCA, & IAPMO Uniform Plumbing Code)

Fill Valve – Most commonly referred to as a Ball Cock, the fill valve controls water to the tank of a tank type toilet. The fill valves is operated by means of a float. Most fill valves also have an anti siphon device  or vacuum breaker to ensure there is no cross contamination from the water in the tank to the potable water supply.

Filtration – The process of the flow of water running through a filter medium.

Fixture Carriers – A device that is installed behind a finished wall and anchored to the floor to mount and off the floor plumbing fixtures i.e., lavatories, wall hung toilets, urinals and slop sinks. It is most commonly used in commercial and institutional applications due to increases wear and tear.

Fixture Units (Drainage) – The quantity of load producing effects a plumbing fixture has on a plumbing drainage system. The number is based on the probable discharge of waste water into the plumbing drainage system by different fixtures for a single operation and on the average time between operations. The rate of discharge through a plumbing fixture of 7.5 GPM is termed one fixture unit.

Fixture Units (Supply) – The measure of how much water a plumbing fixture needs for proper function. The plumbing valve used by a particular fixture and its function is based on the volume of water it uses on a single occasion and on the average time between operations.

Floor CleanoutsA readily accessible opening installed in the floor off of a horizontal waste line to accommodate drain cleaning equipment to remove potential blockages.

Floor DrainsAn opening in the floor used to drain potential liquid waste from the floors into the drainage system. Floor drains are most commonly seen in basements, core toilet rooms, janitor’s closets and mechanical rooms.

Floor Sinks – A receptor installed in a floor that receives drainage from indirect waste lines. Floor sinks are often glazed with porcelain or epoxy to inhibit bacterial growth and to make it easier to clean and maintain.

Flushometer Valve –  There are several different type of flushometer valves on the market the diaphragm type valve invented by William Sloan and the Sloan Valve Company in 1906 is the undisputed leader in Flush valve production and market use. However all flushometers are designed to do the same thing and that is to deliver a measured amount of water to a fixture to flush out waste, i.e. a water closet or urinal. Both a diaphragm and a piston type flush valve operate by using water pressure to actuate the valve.

(Plumbing) – Plumbers flux comes in the form of paste and it is brushed on copper or brass pipe and fittings to remove oxides and other coatings for the metals before joining. Oxides make soldering difficult. Upon heating the pipe/fittings and flux, the flux will clean and float away any oxides or particulates.

Friction (Water Piping) – It is the resistance between to objects in contact with one another. In a water piping system it is the friction that occurs between water and the walls of the piping. Water that comes in contact with the walls of the pipe actually moves slower than water in the center of the piping. We call that friction loss in the piping trades.

Friction Clamps/Riser Clamps – A friction or riser clamp is used in the plumbing and mechanical trades to support vertical piping at each floor. The hanger device is place around the piping and tightened with bolts which prevents the piping from slipping. Riser clamps have wings or ears that extend out from the pipe to span the opening in the floor to accommodate the piping being braced.

Riser Clamp

The Riser Clamp is one of the most used pipe hangers in construction.

Frost Proof Hose Bibbs or Sillcocks – A faucet that delivers water to locations (usually outside) for watering landscaping or grass, washing vehicles or general cleaning. When the hose bibb is designated as “Frost Proof” it is usually has an apparatus which allows ice to expand without damaging the unit or connected supply piping.

Futures (Vent, water and waste) – Futures in plumbing are fittings and or piping installed and capped to accommodate “future” plumbing expansions. i.e. an office building is being built and the owner is taking the entire space. However, at some point the owner may want to divide the building to accommodate possible tenants or expansion of existing office space. Futures would minimize the contruction to rehab, expand or reconfigure the existing plumbing systems.

Garabage Disposals – An electrically powered plumbing appliance installed on the outlet of a kitchen sink that is used to grind up leftover organic waste so it is easily rinsed away by LOTS OF WATER. Garbage disposal are manufactured in several different price points which include better build quality, sound deadening materials and features. Commercial versions are also available.

Gas Piping – The piping used to deliver propane or natural gas to a home and it’s gas powered appliances in the home i.e. stove, oven, and clothes dryer.

Gate Valves – The gate valve is typically operated by a wheel handle and that handle lifts and lowers a metal disc or wedge cutting off or opening the flow of water. A gate valve should not be used to throttle or regulate the flow of water. Gate valves are usually described as rising stem sometimes called an OS&Y (Outside Screw and Yoke) or non-rising stem.

Nibco OS&Y Valve

Nibco OS&Y Valve

OS&Y valves are used in situations were it is beneficial and sometimes safer to be able to see if the valve is in the open or closed position by seeing whether the stem is visible or fully seated.

Nibco Gate Valve Non Rising Stem

Nicbo Non Rising Stem Gate Valve

General Liability Insurance (GL Insurance) – A standard insurance policy issued to businesses but in this case plumbing and mechanical businesses to protect against liability claims generating from the operations the business performs this includes employee negligence. This is usually coupled with Workers Compensation Insurance to form a firms commercial insurance package.

G.P.M. – (Gallons Per Minute) A unit of measurement used by plumbing material manufacturers to convey performance or measure capacities of a fixture, water piping and or waste piping.

Gravity Sewers – All sewers work by by gravity. However this term is used by plumbers to describe a house drain which runs under the basement floor and receives the discharge from soil, waste and other drainage from pipes within the building. It is almost always used to describe a sewer when a home is affected by sewage backing up from the city sewer during extreme rain fall. The solution to a gravity sewer would be to run the sewer over head. (See Over Head Sewers)

Gray Water – is defined as water generated by sinks, showers, bathtubs and clothes washers. It does not contain waste water from water closets, urinals, kitchen sinks or waste from dishwashers.

Gray Water Waste Pipe System – Is the piping and storage system that collects waste water generated from hand sinks, showers, bathtubs and clothes washers. Because over 60% of all household water usage can be labelled as gray water systems have been developed to recycle this water and reuse. Graywater piping is purple in color so it will standout amongst other piping systems.

There are three separate steps in the graywater recycling process and they are as follows:

  • Collection –  Graywater and black water wastes systems are piped separately. The graywater is harvested is storage tanks.
  • Treatment – Depending on the use the waste water is filtered. There are a multitude of ways to implement the filtration process but the most common is using physical media.
  • Disinfection – The filtered graywater is disinfected using UV, chlorination or iodine or a combination of the aforementioned.

Grease Traps or Grease Separator – A device designed to cause separation and retention of oil and/or grease from liquid wastes. Grease separators are most commonly used in commercial kitchens, restaurants or apartment buildings. Periodic grease removal maintenance needs to be done in order to maintain performance levels.

Green Plumbing – Is any type of plumbing that promotes conservation of water and or electricity.

  • Gray Water
  • Low Consumption Plumbing Fixtures
  • Rain Water Harvesting
  • Solar Hot Water
  • Tankless or Self Condensing Hotwater
  • Waterless Urinals

Hair Separator or Hair Trap – these are installed on lavatories or sinks in beauty salons or barber shops and they catch link or hair from entering the waste piping. They are equipped with a removable basket that must be cleaned regularly to maintain proper flow. They also have a secondary purpose as they safeguard against losing jewelry if dropped down the drain.

Hand Held Shower with Slide Bar – A shower head that is attached to a flexible hose and can be moved up or down on a stationary slide bar or removed from a holder and used to rinse the hair and body. Originally designed as necessary item for the elderly and handicapped it has now become a premium upgrade in home showers.

Hand or Sink Auger – This is a coiled flexible cable that is contained inside a metal cannister and has a self feeding auger bit to dig through blockages in small diameter piping. The cannister is usually equipped with a handle and a knob so you can turn the rod cleaning the pipe of debris.See the  full sink auger definition.

Hard Water – Hard water is a condition caused by minerals dissolved in water. There are many minerals that can be dissolved in water but the primary are Calcium and Magnesium. 85% of the water in the U.S is considered hard water. Some of the symptoms a homeowner will experience if they have hard water will be spots on their dishware, rings around the bathtub, scale build-up on shower heads and aerators on sink faucets. Hard water also reacts with cleaning products and detergents reducing it’s effectiveness. Hard water treatment comes in several forms the most common is an ion exchange based water softener.

Head Pressure – It is the difference in elevation between two points of water expressed in weight of a given height of a column of water. The pressure at the bottom of the column of water is greater than at the top of the column and that pressure is independent of the volume of water present. For instance the “head pressure” of a column of water that is 15ft high in a 3″ pipe is the same as if the pipe were 3ft in diameter.

Heat Exchanger – A heat exchanger is an apparatus such as coiled copper or stainless steel tubing that is submerged in a tank of water. That coil is used to transfer the heat from the liquid in the tubing to the water in the tank by way of the metal surface.

Heat Traps – On water heaters a heat trap allows cold water to flow into the the heater but prevents hot water from flow out of the tank when not in use. Having heat traps provides energy cost savings by preventing heated water from escaping the tank so it doesn’t have to be brought up to temperature again.

Hoar Frost – In plumbing it is the frost that forms on vent stacks from water vapor coming in direct contact with air that is below freezing. The thought is that with continual sub freezing temperatures that layer upon layer of hoar frost can eventually close off vent stacks compromising the proper function of the waste system in a home or building.

Hose Bibbs or Sillcocks – A faucet that delivers water to locations (usually outside) for watering landscaping or grass, washing vehicles or general cleaning.

Hot Tap – The process of tapping into water main or water supply line while the line is still active and in use. The process was developed to minimize down time to other homeowners or building tenants during maintenance, rehab or new construction. The alternative to hot tapping or pressure tapping would be to shut down and drain down the affected section of piping so the work could be completed.

Hot Water Return Piping – Hot water return piping is piping connecting the end of a run of plumbing fixtures and/or appliances back to a hot water source i.e. a water heater or boiler. Most times a hot water return line is installed with a recirculating pump to insure hot water is always recirculating through the hot water supply piping. Keeping hot water recirculating through the line dramatically cuts down on the time it takes to get hot water to a fixture. The average family wastes 12,000 gallons per year waiting for hot water.

House Drain – The House Drain is the lowest part of the drainage system piping that receives all of the soil and waste discharge from other drainage piping within a home or building and discharges it to the house sewer that begins 5ft outside of the building.

House Pumps (Domestic Water Booster Pumps) Variable Frequency or constant speed. Uses in commercial and residential. Most plumbing fixtures and equipment need a minimum amount of water pressure to function properly, a house pump or booster pump takes incoming water and increases the pressure to accommodate the water demands of a private residence or a commercial building.

House Sewer – The part of the horizontal piping of a plumbing or drainage system that extends from the house drain to it’s connection with the main sewer or other place of sewage disposal. So the piping that connects the interior sewer to it’s connection to the municipal sewer.

House Trap – Although there are many homes that still have a house trap in use they are generally frowned upon. A house trap is a trap installed on the house drain to prevent sewer gases and vermin from entering a residence or commercial building. The biggest issues with house traps are that if the trap is ever compromised the entire building is susceptible to sewer gases.

Hub and Spigot Soil Pipe – Hub and spigot soil pipe is usually made of cast iron and is used in sanitary drain, waste and vent, sewer and storm drainage applications. The pipe and fittings have a bell on one end and are plain on the other. The plain end is inserted into the bell or spigot end and the joint is sealed using a rubber soil gasket or braided oakum and lead.

Hydraulic Pressure – The pressure applied by a liquid against an object. Most liquids cannot be compressed into a small area like air can. Therefore when a liquid is applying pressure to an object the liquid will find it’s way around the object or if need be through the object.

IAPMO Plumbing Code ( The International Association of Plumbing and Mechnical Offiicials) or UPC (Universal Plumbing Code) – This is the most update and accurate set of current plumbing practices, it is produced by plumbers and mechanical engineers. It includes installations for potable water, building water supply and distribution, waste drainage and vent piping, sewer mains and plumbing fixtures. It also defines material and code approved joining methods.

Ice Maker – A plumbing appurtenance that can be stand alone or part of a refrigerator and is used to make ice for beverages or for therapeutic uses. An ice maker needs both a water connection and a waste connection for the discharge of condensate waste.

Indirect Waste Pipe – Waste piping from a plumbing fixture or appurtenance  that isn’t connected directly to the waste drainage system of a home or building but instead it drains into the drainage system through an air gap and into a fixture, interceptor or receptacle like a floor sink which is properly trapped and vented.

Instantaneous Water Heaters – An instantaneous water can be broken down into the following two categories.

  • Point of Use – A point of use water heater is installed at or near a plumbing fixture or battery of fixtures and it used to service those fixtures alone. Their capacity to flash heat water is limited. They are mainly used in situations where it is too difficult to tie into and existing hot water source or a small bathroom or sink has been added and has a limited need for hot water.
  • Tankless Water Heaters – Both of these heaters are tankless however, when someone refers to a tankless water heater they usually mean a high capacity heater used to serve multiple locations in a home or business.

A tankless heater flash heats water on demand by pulling water through a heat exchanger. There is no hot water storage although one can be added if the application calls for additional capacity. Tankless heaters are generally thought of to be much more efficient than traditional tank type water heaters. However, real world use has clouded that belief.

International Plumbing Code or IPC – The International Plumbing Code was first adopted in 1995 and it was really a combined effort as representatives from BOCA, ICBO and the SBCCI were all used to produce an all inclusive set of rules and regulations based on existing model codes.

The IPC was established to set standards to adequately protect the public health and safety but not necessarily increase the cost of building and fabrication.

There are several states and municipalities that have adopted the IPC as their plumbing code. The IPC can be adopted internationally.

Invert – The lowest point of the inside of any type of horizontal waste, vent or water piping.

Invert Elevation – Closely associated with the above, the invert elevation is really the cornerstone elevation for the mechanical and in particular the plumbing trade. It is the lowest inside point of any pipe at a certain location. Knowing invert elevations are extremely important for laying out waste piping runs. Mistakes can cause mistakes ranging from sewer piping not having enough pitch to waste piping being removed because it is above the ground or hanging below a drop ceiling.

Iron Filter Tank – Any device that removes disolved or undissolved iron from potable drinking water. Some smaller units can be installed in line with your water main and need to be maintained by changing a removable media. There are also iron filters that can handle removing iron for the whole house using media that can be recharged relieving the homeowner of having to change the filter once a month. See Charger Water Treatment for their solutions on treating potable drinking water.

Island Vent – (See Loop Vent)

Isolation Valves – Any type of valve installed on the potable water system that isolates a section of a building, a battery of bathrooms or plumbing mechnical equipment i.e. a house pump. Isolation valves allow plumbers positively shut down the water supply to the aforementioned so work can be performed without shutting down the water supply to the entire building.

J-Hooks – J type hooks are used in just about every industry. In the plumbing industry they are made of plastic, steel or copper plated and come in different sizes to accommodate different sized pipe. They look like the letter “J” and are usually nailed or screwed into a wooden or steel joist to hang waster, vent and water piping.

Kitchen Sink Faucet with a Pull-Out Spray – Kitchen sink faucets are manufactured with or without a spray mechanism. In the last 20 years most of the faucet manufacturers have come out with kitchen faucets with a sprayer that pulls out from the spout. The spray head will have a function button that when depressed will switch the function between hard spray or aerated flow. Since their inception they have become extremely popular due to the fact that you don’t have to have a side spray taking up space on the faucet deck to have the same functionality.

Lavatories – See plumbing fixtures

Lead – A soft and extremely heavy metal was used in almost every aspect of the plumbing industry at one time or another. Most major cities in the US used water services made of lead piping because of its durability and malleability. Using lead for piping went out of favor in the 80’s due to fear of lead leeching. Until very recently lead was being used in trace amount for faucets, flush valves, hose bibbs etc., however stricter laws have made using lead illegal. There is one area where lead is used and it’s only in certain places around the country and that is for yarning and pouring joints on cast iron waste piping.

Lead Flashings – thin sheets of lead used to water proof vent stacks through the roof. A tube of lead is made slightly larger in diamter than the piping being flashed, that tube is welded on to flat piece of lead. The lead flashing is installed over the vent through roof increaser and the end of the lead is pounded down inside the piping. The roofing material is placed over the flashing and around the pipe and is sealed. Vent flashings are also made of rubber membrane.

Lead Pan – Lead pans have been used in plumbing  for a number of reasons. As a durable malleable material to use to water proof a shower or mop basin where stone or tile is being used as flooring, as a drain pan used to catch water from a water heater should it start to leak. You being with a flat piece of sheet lead

Lead Pick – This a tool that looks like an awl, with a metal tip bent at a 90° angle or like a hook, that is used while drilling out an old lead joint, to pick out the loose lead and oakum.

Lead Pot and Ladel – Used primarily to pour lead and oakum joints for waste and vent piping. A lead pot is made of cast iron and lots similar to a cooking pot. It is made to sit securely on top of furnace that attaches to plumbers propane tank. Lead is placed inside the lead pot and is heated until melted. A cast iron ladel is used to extact the molten lead from the pot so it can be poured into a hub. Molten lead does not stick to cast so it can be poured easily.

Lead Water Services – Lead was the material of choice for water services in all major municipalities until the end of the 1960’s. Because lead is malleable and utterly non-corrosive it was a go to for plumbers for the better part of a century. It wasn’t until we became aware of the harmful effects of lead poisoning that lead services were discontinued. The funny things about lead water services is that a hard scale barrier forms over the piping exposed to potable water so quickly that there is no measurable leeching however I suppose it’s better to be safe than sorry.

Liquid Waste – Any liquid discharge from a plumbing fixture that does not contain human or animal waste matter.

Loop Vent – Some times this is referred to as an island vent because if you do vent your island you’d use a loop vent. A island loop vent begins at the discharge from island sink using a sanitary tee. The vent rises up above the discharge of the drain then drops back down and connects back to the drainage system below the floor. A loop vent in a commercial application has a different meaning; it is a single vent pipe connected to the horizontal drainage piping that receives the discharge from one or more unvented fixtures. The single vent pipe rises above the overflow level of the highest unvented fixture and the single vent is connected back to the vent stack. Basically this is a way to vent a battery of fixtures using a single vent pipe.

Main Pipe – The central pipe line to which all other branches are connected. This covers all plumbing piping systems i.e. waste, vent and water piping.

Man Hole – A circular cover usually manufactured from cast iron that is part of a larger concrete structure used for easy excess to any number of below grade plumbing equipment. i.e. below ground valves, ejector or grinder pumps. A manhole can also be used as an access point for rodding and drain cleaning equipment on storm and sewer lines.

Mechanical Joints – definition, materials used, types of mechanical joints. Any type of pipe and fitting joining method that ensures a water tight seal using the following: gaskets, couplings, grooved fittings and couplings, nuts and bolts, etc. The following are examples of mechanical joints:

  • No-Hub Couplings
  • Mission Couplings
  • Victaulic Grooved Fittings and Couplings
  • Gruvlok Grooved Fittings and Couplings
  • Flanged Fittings using nuts, bolts and gasket kits.

Mechanics Lien – A form of legal protection afforded to contractors and suppliers obtained as collateral against unpaid bills. When enforced any real estate or property such as a home or commercial building can be sold to pay off past due bills. As a mechanical contractor you should always protect your lien rights. The time for filing an Intent to Lien is different from state to state but usually you have 90 days from the performance of work to file an Intent to Lien. Once that time passes you will be forced to litigate but your lien rights will expire.

Mini-Widespread Faucet – A style of lavatory faucet that has a separate spout and handles but fits on a lavatory with a 4″ spread and opposed to a widespread faucet which fits on a lavatory with an 8″ spread.

Mixing Valve – A plumbing valve that mixes hot and cold water and delivers them at a specific temperature.

Molded Stone – Molded stone is most commonly used for laundry tubs and it is really used to describe a fiberglass product impregnated with a calcium resin. It’s extremely durable while being low cost. Consumers may think the term molded stone is misleading however it’s a term that has been used in the plumbing industry for decades.

Mop Basins – See plumbing fixtures

National Plumbing Code – This is a standard code book for the plumbing industry that covers BOCA (Building Officials and Code Administrator International) and UPC codes highlighting specifications and best practices and procedures for installation and standard plumbing materials

Nipples -A short piece of pipe threaded on both ends used to join two threaded fittings.

No Hub Soil Pipe – A type of pipe normally made of cast iron, without hubs, joined with no hub couplings


  • White Oakum – ​Hemp fibers treated with bentonite a type of drilling mud that expands when exposed to liquids. It is the preferred oakum used in yarning and pouring cast iron hub and spigot joints because when water enters the joint it expands making the seal water tight.   ​​
  • Brown Oakum – ​Hemp fibers that have been treated with petroleum based pitch to make it water resistant. It is much more difficult to work with in hub and spigot joints because it doesn’t compact like white oakum.  ​​

Open Site Drain – ​A trap, fixture, drain or interceptor that receives waste from a plumbing fixture by way of an indirect connection through an air gap. This allows for a fixture to drain however, if the drain experiences a backup the waste will not back-up into the fixture itself. It will spill on to a floor so as not to contaminate the fixture. An example of a fixture that would use an open site drain would be kitchen prep sink. ​​

Organic – Any substance pertaining to something living. Substance must contain carbon.

Over Head Sewers – ​​​A sewer in a building or home that receives all waste and is piped in a basement ceiling. The sewer exits the building over head and then drops down outside the building to a municipal sewer. Although all sewers drain by gravity this differs from a gravity sewer in that all waste from a gravity sewer ​​​​​​runs underneath a basement floor and out of the building.

Overflow roof drains – See PlumbingMechanical Equipment

Pathogenic – Any material capable of causing disease or containing bacteria or viruses.

PCA (Plumbing Contractor Association) – ​The Plumbing Contractors Association of Chicagoland is one of the old trade association in the United States. It includes representation from both Labor Management and Contractors and promotes the highest standards of the plumbing craft and supports the training of plumbing tradesmen and apprentices. They also keep members up to date on the latest trends in the industry. ​​

Pex Plastic Water Piping and Fittings – PEX (cross linked polyethylene) is a type of flexible tubing used for potable water in homes and commercial buildings. PEX was originally used for radiant heating inside concrete floors. When PEX was first introduced there were numerous complaints that it deteriorated over time. It was discovered that the chlorine used to disinfect potable water attacked and slightly deteriorated the material. Since then improvements have been made to alleviate those issues.Currently PEX is approved for use all across the US for potable water. Because of PEX’s flexibility it is the choice for home improvement and DIYers. It’s easy to install and you don’t have to be perfect with your measurements. We call it garden hose in the wall because it isn’t a pretty install but it works and works well. Because of the improvements in PEX manifolds you can literally control water to every fixture in the house or building. Gone are the day of shutting the entire water down to fix one leaky lavatory or toilet.

PHCC – (Plumbing Heating Cooling Contractors Association) – In 1883 125 members formed the National Association of Master Plumbers (NAMP) which was the forerunner to the PHCC which was officially formed in 1962. Now the PHCC is comprised of 125 charter organizations encompassing 3,300 union and open shop businesses. The PHCC is dedicated to furthering education and professional excellence throughout the mechanical trades.

Pipe Condensation – ​Cold water lines attract moisture from the air just like a cold glass of water attracts moisture on a warm summer day. If enough condensation forms on the cold water piping it can drip down on to ceiling tiles, desks etc. causing damage. Cold water lines are frequently insulated to shield the piping from the air surrounding the piping. Insulation can also absorb any potential condensation preventing potential damage.

Pipe Insulation – Insulation made of foam or fiberglass that wraps around domestic water piping to eliminate condensation from forming and possibly dropping on ceilings or people below.

Pipe Labeling – Quite often In commercial buildings the building specifies that all piping must be identified with labels. This makes is easier for the building engineers or service contractors to identify what they are working on. Certain pipes have readily identifiable colors for instance Domestic Cold Water is printed on a green label with an arrow to denote flow direction, Domestic Hot Water is printed on a yellow label with an arrow to denote flow direction. Pipe labels are not exclusive to water piping. Waste, Vent and mechanical water piping are also labelled as well.

Plumbing Council of Chicagoland – The PCA and plumbing council were once two different organizations. The Plumbing Council was responsible for the collection of monies from the industry fund responsible for advertising the union plumbing industry in Chicago. The PCA is an entity comprised of signatory contractors that negotiate with the union for wage increases and education. Recently they have combined staffs and resources and work together for the common good of the industry.

Plumbing Fixtures – Gosh it’s tough for us to define this term because it’s so outdated. We’ll give it a shot, it’s a device, appliance or “appurtenance” that is hooked up or installed to the potable water system which makes the potable water available to flush liquids or liquid born wastes either directly or indirectly into the waste system.

Plumbing Mechanical Equipment
Some may disagree with how some of these are defined but for this site each of the following will be referred to as plumbing mechanical equipment:
Coffee Makers

Define boilers, types, uses
Water Heaters – (Please see Water Heaters here) No need to define it again. You can read all about it in the link

House or Booster Pumps – A house or booster pump is connected to the incoming domestic water line and raises the pressure of the water to the building. In a homes across the US the water pressure is too low to ensure proper function of the plumbing fixtures and equipment so a booster pump is installed. These can be simple or complex. Meaning there are pumps that you can turn on when extra demand is called for or they are automatic and turn on when extra demand is needed. In commercial (Hi-Rise) or industrial building the incoming water pressure can be adequate however because of the size and demand of the building the pressure will diminishes as it gets to the fixtures. The plumbing fixtures closest to the incoming water main will function fine but as you get further and further away from the source the water pressure goes down. The booster pump will ensure all fixtures and equipment have adequate pressure. These booster systems are usually designed by an engineer using specifications denoting how much water is needed.

Ice Maker – This is going to be real simple. It’s an appliance that turns potable water into ice for beverages or for therapeutic purposes. Ice makers come in many sizes and shapes but they can be divided into two basic types. Consumer versions that most commonly built into a refrigerator and commercial which is usually stand alone and produces high volumes of ice.

Plumbing Trap – A fitting placed in a drain line from a plumbing fixture for the purpose of holding water or other fluid to form a trap seal that prevents the passage of gases, odors or vermin from the drain pipe into the building.  Click on the link for a much more detailed account of Plumbing Traps

Plumbing Valve – is any valve used to regulate the flow of water in a potable or human waste water system.

Point of Use Water Heaters – A point of use water heater is usually of tankless design however some do hold some water. These heaters are made to be used for a single fixture or a battery of fixtures at a single location. Point of use water heaters are usually powered by electricity rather than gas.

Power Jetter – A power jetter takes water from a water supply either from a home, building or a self contained source and cranks up the pressure via a motor of some kind. The water pressure is further increased by the type of nozzle at the end of the jetter hose. Power jetters come in many different sizes and configurations. You can use small walk behind units that can double as power washers or they can be tow behind units that are much more powerful and can be used in a variety of applications or they literally be full trucks with their own water source. Each type of jetter has their place in the plumbing service space. For can find more on topic on my sewer rodding and jetting article.

Power Rodder – A rodder or auger consists of a tightly coiled steel cable (think of a very long, very strong spring) usually made in precut lengths or coiled in self contained canisters. instead of you doing the cranking to remove a blockage a motor either rotates the coil using jaws. These are usually used when a simple canister auger or tape auger won’t do the trick. They come in a variety of sizes and types mostly based on the type of job. Most service plumbing contractors have a variety of units at their disposal.

Pressure Assisted Toilets – When Sloan invented the Flushmate it was like a skies opened and we were given a gift from the plumbing Gods. Sloan’s engineers manufactured a pressurized tank to fit inside the toilet tank. As water enters the tank it pressurizes the air inside it and then a valve closes. Now you have a tank filled with pressurized water. When you engage the tank lever the air pushes the water into the bowl evacuating the contents. The Flushmate was the first product designed for pressure assisted toilets and it was used in many manufacturers pressure assisted line. Recently several companies have designed their own pressure assisted systems.

Priming a P-trap – If a trap of any kind isn’t used for some time the water that seals the trap can become foul or evaporate letting in unwanted sewer gas into a room or building. Priming the trap is the act of refilling the water in trap creating a trap seal.

PVC Plastic Pipe and Fittings – PVC plastic is formally known as Polyvinyl Chloride. It is strong, smooth and cost effective and it is code approved for waste and vent throughout the United States.

PVD Finishes – Stands for Physical Vapor Deposition, it is a metal plating process performed in vacuum chamber. The process allows metals to adhere to a base metal and is much more durable than traditional electo-plating. Most finishes produced by the major plumbing manufacturers are now PVD finishes and they are usually guaranteed for life.

Private Sewer – Any sewer that serves one or more buildings that is privately owned and is not directly controlled or maintained by a public entity.

Public Sewer – Any common sewer controlled and maintained by a city, county, state or federal government.

Radiant Heat – In plumbing or HVAC radiant heat is a closed loop system. flexible piping is run underneath the floor in concrete or through guides. The water or freeze proof liquid (depending on application) is warmed by a boiler or water heater. The heat radiates from below warming a room or melting the snow if used in drive way.

Rate of Flow – This is a term used to describe the volume of moving water as it related to a time period. The most common measurement used in plumbing is gallons per minute (GPM) or gallons per hour (GPH).

Re-circulating Pump

Repair Flanges

Reverse Osmosis Water Filtration

Roll Groove

Roman Tub Filler
Roof Drain – a roof drain is a plumbing appurtenance installed on a building roof, inside a gutter or in a parapet wall to receive rain water. The water is routed to the building or structures downspout piping and discharged to a storm sewer or is allowed to splash on the ground. Please check your local plumbing codes to find out acceptable methods for the discharge of rain water.


RPZ (Reduced Pressure Zone)

Sand and Sediment Separators

Syphonic roof drains

Sanitary Sewer – A house drain or a house sewer designed and used to remove only sewage. Storm water need not apply. Believe it or not there are places around the country that separate the storm and sewage systems in a building only to let them combine outside the building to a combined sewer.

Septic Tank – A tank designed to receive raw sewage. Through aerobic and anaerobic bacterial action and sedimentation the sewage is allowed to break down. After a period of detention the remaining liquid is allowed to discharge into the soil.

Sewage – A combination of water carried wastes from a residence, business buildings, institutional and industrial buildings together with ground surface and storm water.

Sewer Camera and Locator

Shower Head

Slip Joint

Sloan Flush Mate


Soaker Tub

Soft Water

Soil Pipe – Any piping which transports the discharges of one of more water closets or bedpan washers with or without the discharge from other fixtures to the house drain.


Solder Joints – types, uses (How To)

Spanner Flanges

Stand Pipe

Steam Generators

Steel Pipe and Fittings

Storm Piping


Sub-Soil Drain – The part of the drainage system which transports subsoil ground or seepage water to the house drain or house sewer. (Most times it’s called drain tile.)

Suds Zone

Sump Check Valves

Sump Pits

Sump Pumps

Sump Silent Check Valves

Suspended Solids – The solid waste material held afloat or suspended in the transport medium in this case it’s water.

Sustaining Hinge Check

Syphonic roof drains

T&P Valves – A relief valve used on tanks or vessels that is activated by too much temperature(T) or too much pressure (P)

Tempering Valves – A valve used to control temperature to a constant temperature. These valves are mechanical in nature meaning a temperature can be set with a set and locked in and won’t allow any more hot water through the valve. Hot and cold water flow is controlled by the internal ports.

Thermal Expansion – The expansion of water or material from heat

Thermostatic Mixing Valves – A pressure balanced valve used to control temperature of water based on both the hot and cold water supply temperatures and changes in water pressure. A valve that is pressure balanced only operates on just that….pressure

ToiletsA plumbing fixture designed to receive human excrement from the user of the fixture to the sanitary sewer system.

TrapA device for a plumbing drain, sewer, etc. consisting of a tubular bend in which a liquid settles a forms a seal preventing sewer gasses, vermin, stench from coming back into a building.

Trap Primers – A device used to prime a p-trap, preventing the evaporation of water form the trap

Trap Weir- The highest point of water held in a trap (either p-trap or s-trap) before it leaves the trap and drains

Trapeze Pipe Hanger

Two Hole Pipe Straps


United Association (UA)

Urinals – A plumbing fixture that is flushed by potable water that is designed to receive human urine, the discharge is disposed into the sanitary system.

UV Purification

Vacuum Breakers

Velocity – The rate of speed at which water moves through piping. It is measured in feet per second.

Valve Tags

Vent Increaser – Why they’re used. Controversy on their usefulness

Vent Piping

Vent Stack

Vibration Isolation

Vitreous China

Wafer Check Valve – A wafer style check valve is obviously a check valve that is used when space constraints won’t allow traditional check valves to be used. Some of the other benefits of using a wafer check is weight, this style of check doesn’t need as much support as it’s traditional full body counterpart.

A wafer valve is made using a thin disc that can be fastened in the center or the top or can be spring loaded in the center.

This valve is meant to placed between two flanged fittings and secured between the two fittings with all thread rod. The valve is notched in the same positions as the bolt pattern of the flanges so the rod can pass by the valve. The valve is secured at both ends by the flanges.

Walk-In Shower

Washing Machine Boxes

Waste Piping

Waste Stack

Water Hammer

Water Hammer Arrestors

Water Heaters

Water Meters

Water Piping

Water Risers

Water Service

Water Softners

Wet Vent

Workmen’s Compensation Insurance

Yard Hydrants

Yarning and Packing Irons

Sand and Sediment Separators

Syphonic roof drains

Thermostatic Mixing Valves

Thermostatic Mixing Valves

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