Plumbing Engineering

plumbing banner 1Plumbing is a system of pipes, valves, fittings, and other equipment used for the distribution of water, gas, and other fluids throughout a building or structure.  These systems are essential for the delivery of clean water, the removal of waste and sewage, and the safe and efficient distribution of heat and gas.  They may include fixtures such as sinks, toilets, bathtubs, showers, and water heaters, as well as pipes and valves that transport water and gas.  Proper installation and maintenance of plumbing systems are important to prevent leaks, water damage, and other potential hazards.  Plumbers are professionals who specialize in the installation, repair, and maintenance of plumbing systems.

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Plumbing Engineering Index


Plumbing Systems

  • Water Supply System  -  A water system that collects, distributes, stores, and treats water for consumption.
    • Pottable Water  -  Denotes whether water is suitable for human consumption.
    • Single-main  -  A single main supplies both sides of the street.
    • Double-main  -  There is a main on each side of the street.  Each main supplies domestic and fire water for it's side of the street.
  • Sanitary Drainage System  -  A collection system of underground piping for waste water, that flows to pumping stations where it is processed to clean water.
    • Gravity  -  A drainage system that uses a natural slope or constructed slope to take away the sewage.
    • Low Pressure  -  An underground collection system consisting of an interceptor tank and a chamber unit, which houses a small, submersible pump.  The tank treats the waste water before transporting under pressure to a wastewater plant.
    • Vacuum  -  The drainage system is under negative pressure that allows piping to run vertically up walls and across ceilings.
  • Venting and Drainage System  -  Used to divert gasses produced by wastewater from buildings to the outside.  There should be enough water in the drainage system to prevent the gasses from excaping to the vents.
    • Pipe  -  The pipes flow in a downward gravity direction to ensure the plumbing has proper flow.
    • Trap  -  Also called P traps, a U-shaped pipes used to prevent backflow.
    • Vent  -  The vent runs from the roof to the drain pipe and releases air into the plumbing piping to ensure smooth drainage.
  • Stormwater Drainage System  -  A network of structures, underground piping, and channels, that recieve stormwater, then carry it away to ponds, streams, rivers, and lakes.
    • Roof  -  Water accumulated from the roof travels down a pipe system to grade or a stormwater drainage system.
    • Surface  -  Paved or unpaved area accumulated water can be drained of to ponds, storm drains, and ect.
    • Subsoil  -  Water that soaks into the ground and drained off by a drainage system.
  • Gas Piping System  -  Natural gas and propane gas are the most common gasses used and can include boilers, HVAC, and stoves.
  • Exterior Piping System  -  These systems normally use plastic pipe and can include hot tubs, sprinkler systems, swimming pools, and other outdoor activities.


Plumbing Engineering standards

ASME Standards

  • ASME B16.1 - Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250
  • ASME B16.5 - Pipe Flanges and Flanged Fittings: NPS 1/2 through NPS 24 Metric/Inch Standard
  • ASME B16.24 - Cast Copper Alloy Pipe Flanges and Flanged Fittings: Classes 150, 300, 600, 900, 1500, and 2500
  • ASME B16.36 - Orifice Flanges
  • ASME B16.42 - Ductile Iron Pipe Flanges and Flanged Fittings: Classes 150 and 300
  • ASME B16.47 - Large Diameter Steel Flanges, NPS 26 Through NPS 60

ASTM Standards

  • ASTM A105 / A105M - Specification for Carbon Steel Forgings for Piping Applications

AWWA Standards

  • AWWA C115 - Standard for Flanged Ductile Iron Pipe with Ductile-Iron or Gray-Iron Threaded Flanges

ISO Standards

  • ISO 5251 - Stainless steel butt-welding fittings

MSS Standards

  • MSS SP-9 - Spot Facing for Bronze, Iron and Steel Flanges
  • MSS SP-25 - Standard Marking Systems for Valves, Fittings, Flanges, and Unions
  • MSS SP-44 - Steel Pipeline Flanges
  • MSS SP-106 - Cast Copper Alloy Flanges and Flanged Fittings Class 125,150, and 300


Plumbing Abbreviations

  • Aerator (AER)
  • Air Gap (AG)
  • Back Flush (BF)
  • Basin (BSN)
  • Basket Strainer  (BSTR)
  • Bath Tub (BT)
  • Bibb (BIBB)
  • British Thermal Unit (BTU)
  • Cast Iron (CI)
  • Chlorinated Polyvinyl Chloride (CPVC)
  • Cleanout (CO)
  • Closet (CLO)
  • Closet Auger (CLOA)
  • Cold Water (CW)
  • Cold Working Pressure (CWP)
  • Copper (Cu)
  • Dish Water (DW)
  • Diverter (DIV)
  • Down Pipe (DP)
  • Drain (DR)
  • Drainage, Waste & Vent (DWV)
  • Drinking Fountain (DF)
  • Dynamic Pressure (DP
  • Fiberglass  (FGL)
  • Fixture Unit (FU)
  • Float Ball (FB)
  • Floor Drain (FD)
  • Hose Thread (HT)
  • Hot Water (HW)
  • Hot Water Service (HWS)
  • Hot Water Tank (HWT)
  • Inspection Chamber (IC)
  • Inspection Shaft (IS)
  • Iron Pipe Size (IPS)
  • Iron Pipe Thread (IPT)
  • Laundry Tray (LT)
  • Lavatory (LAV)
  • Low Water Cut Off  (LWCO)
  • Male Hose Thread (MHT)
  • Male Pipe Thread (MPT)
  • National Pipe Thread (NPT)
  • Outside Diameter (OD)
  • Point of Connection (POC)
  • Polyvinyl Chloride (PVC)
  • Pressure Reducing Valve (PRV)
  • Pressure Regulator (PR)
  • Relief Valve (RV)
  • Relief Vent (RV)
  • Riser (RSR)
  • Roof Drain (RD)
  • Schedule (SCH)
  • Service Sink (SS)
  • Sewer (SWR)
  • Shower (SH)
  • Static Pressure (SP)
  • Storm Water Pipe (SWP)
  • Strainer (STR)
  • Street Elbow (SEL)
  • Urinal (UR)
  • Vent through the Roof (VTR)
  • Water Closet (WC)
  • Working Pressure (WP)
  • Y Strainer (YSTR)


Tags: Abbreviations Nomenclature and Symbols

Plumbing Engineering GlossaRy


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  • ABS (Acrylonitrile Butadiene Styrene)  -  A ridged black plastic pipe used for drain, waste, and vent lines.
  • Aerator  -  A device screwed into the end of a faucet spout that mixes air into flowing water and controls the flow to reduce splashing.
  • Air Gap  -  Air-filled space allowing contaminated water to discharge freely, preventing the contaminated water from ever siphoning back into the potable water supply.
  • Air Lock  -  Blockage in the flow of liquid, especially on the suction side of a pump caused by an air bubble in the line.
  • Angle Stop  -  A shutoff valve between the water pipes and a faucet.
  • Anode Rod  -  A sacrificial rod installed in a water heater that protects the tank from corrosion.
  • Anti-siphon  -  Preventive device for the backflow of liquid into a system.


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  • Back Flow Preventer  -  A device to prevent water from traveling from one system back into any part of the main distribution system.
  • Back Flush  -  Temporarily reverse the normal liquid flow through a plumbing system.
  • Back Pressure  -
  • Back Pressure  -  Pressure that resists the flow of fluid in a piping system.
  • Backwater Valve  -  sewer line valve that prevents sewage from flowing back into the home.
  • Ball Valve  -  A quarter turn valve used for changing the direction of a process stream (divert or shut off).
  • Ball Check Valve  -  Much like a swing check valve but instead of having a gate or guided disk, uses a ball to control flow.
  • Ballcock  -  The fill valve that controls the flow of water from the water supply line into a gravity operated toilet tank.  It is controlled by a float mechanism that floats in the tank water.
  • Barlow's Formula  -  The point just before or at when a pipe or tubing fails under pressure.
  • Basin Wrench  -
  • Basket Strainer  -  Closed vessels that collect solid particles to be separated while passing a fluid through a removable screen.  Comes in two types, single and double.
  • Blowbag  -  A drain-cleaning device consisting of a rubber blatter with a hose fitting on one end and a nozzle on the other.  Water is introduced expanding the bag which grips the pipe the pipe.  Then the bag releases pulsating bursts of water, forcing the water through the pipe to clean the obstruction.
  • Branch  -  Any part of a drain system other than the main, riser, or stack.
  • Branch Vent  -  A vent connected one or more individual vents with a vent stack.
  • BTU (British Thermal Unit)  -  A unit of heat energy required to raise the temperature of 1 pound of water, 1 degree Fahrenheit.


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  • Catch Basin  -  Large underground container, with a grate on the top, for collection of storm water run-off.
  • Centerset  -  Style of bathroom faucet having combined spout and handles, with handles 4 inches apart, center-to-center.
  • Check Valve  -  Valves that are designed to allow the process fluid to flow in only one direction to prevent backflow.
  • Circular Vent  -  Plumbing drainage system vertical vent which is run from the last two traps on a horizontal drain line to the main vent stack of a building drainage system.
  • Cistern  -  Rainwater storage tank, often underground.
  • Cleanout Plug  -  A plug in a trap or drain pipe that provides access for the purpose of cleaning an obstruction.
  • Closet  -  Toilet
  • Closet Auger  -  A flexible rod with a curved end used to access the toilet's built-in trap and remove clogs.
  • Closet Bend  -  A curved fitting mounted immediately below the toilet that connects the closet flange to the toilet reain.
  • Closet Flange  -  An anchoring ring that attaches to the closet bend and secured to the floor.
  • Closing Pressure  -  The pressure at which a valve closes or reseats.
  • Cock  -  A faucet or valve for regulating the flow of water.
  • Common Vent  -  Building drain system vertical vent which connects two or more fixtures branches on the same level.
  • 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.
  • Compression Valve  -  A type of valve that is often used for water faucets.  It is opened and closed by raising or lowering a horizontal disk by a threaded stem.
  • Coupling  -  Vent pipe hood, which protects it from the elements.
  • Culvert  -  A pipe-like construction of concrete that passes under a road to allow drainage.


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  • Dam  -  A barrier in a toilet trapway that controls water level.
  • Darcy-Weisbach Equation  -  A dimensionless number, is the most common way of expressing the pressure drop of a piped fluid.
  • Desanco Fitting  -  A type of compression adapter that connects tubular brass fittings to PVC pipe.
  • Diaphragm  -  Flexable membrane in a valve that deflects down onto a grid area of the valve body to regulate water flow from the supply lines.
  • Dip Tube  -  Tube inside the water heater that sends cold water to the bottom of the tank.
  • Direct Tap  -  Clamping device that allows a branch line to be drilled and tapped off a main line.
  • Discharge Tube  -  Outlet tube that connects a disposer or sump pump to a drain line.
  • Disposal Field  -  A series of trenches conveying the effluent from of septic tank laid in such a manner that the flow will be distributed with reasonable uniformity into natural soil.
  • Dishwasher Tailpiece  -  A flanged adapter connecting a basket strainer to the drainpipe with a dishwasher inlet.
  • Diverter  -  Valve which direct water to various outlets.
  • Dope  -  Lubricant for pipe threads.
  • Drip Leg  -  A stub end pipe placed at a low point in the gas piping to collect condensate and permit its removal.
  • Drum Trap  -  An obsolete, non-vented drain lead or cast iron canister trap formerly used in sewer lines.
  • Duo Valve  -  A twin valve (hot or cold) with a single on/off lever used for washing machine boxes.


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  • E. Coil (Escherichia Coil)  -  One of the members of the coliform groups of bacteria indicating indicating fecal contamination.
  • Earthquake Strap  -  A metal strap used to secure a water heater to the house frame or foundation.
  • Efficiency  -  A product's ability to utilize input energy, expressed as a percentage.
  • Effluenct  -  Septic system liquid waste.
  • Escutcheon  -  A decorative metal flange or trim shield beneath a faucet handle that covers the faucet stem and the hole in the fixture or wall.
  • Expansion tank  - A tank designed to absorb excess pressure due to thermal expansion (closed system).


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  • Fall/Flow  -  The proper slope or pitch of a pipe for adequate drainage.
  • Female Fitting  -  A fitting that receives a pipe or fitting.
  • Finish Plumbing  -  Installation of plumbing fixtures to make the system usable.
  • Flapper Valve  -  The part on the bottom of the toilet tank that opens to allow water to flow from the tank into the bowl.
  • Float Ball  -  The floating ball connected to the ballcock inside the tank that rises and falls with changing water levels in the tank.
  • Floor Flange  -  A fitting that connects a toilet to the floor drain.
  • Flow Rate  -  The amount of fluid that flows in a given time past a specific point.
  • Flushometer  -  Toilet flashing system that uses supply water pressure to compress water to provide a pressurized flush as opposed to a gravity flush.
  • Flux  -  Paste applied to copper pipes and fittings before soldering to help the fusion process and prevent oxidation.
  • Footprint  -  The area of floor space taken up sby a water heater or other appliance.
  • French Drain  -  A covered ditch containing a layer of fitted or loose stone or previous materials.
  • Friction  -  The mechanical resistance to the relative movement of two surfaces.


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  • Gas Cock  -  Plug valve installed in the main gas line and an application.
  • Gas Control  -  Device usd to regulate gas pressure on the water heater.
  • Gate  -  A device that controls the flow in a conduit, pipe, or tunnel.
  • Gate Diverter  -  The pop-up lever on a tub faucet that activates the diverter valve.
  • GPM  -  Gallons per minute
  • Gravity  -  A force pulling togeather all matter.  Everything that has mass has a gavitational pull that is exerted on one another.
  • Gravity Operated Toilet  -  A toilet that relies on the natural downward pressure of water in a toilet tank to flush the toilet effectively.
  • Grease Trap  -  A device that traps the grease and other build-up from entering the sanitation drainage system.
  • Gray Water  -  Waste water from sinks, showers, and bathtubs, but not toilets.


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  • Horizontal Branch  -  Lateral drain pipes that run from plumbing fixtures to the waste stack in a building or in the soil.
  • Horizontal Run  -  The horizontal distance between the point where fluid enters a pipe and the point at which it leaves.
  • Hose Bibb  -  An outdoor faucet, also used to supply washing machines.
  • House Trap  -  U-shaped fitting with two adjacent cleanout plugs visible at floor level if main drain runs under floor.
  • Hubless (No Hub)  -  Cast iton drainage pipe with neoprene gaskets and clamps.
  • Hydronic  -  System of forced hot water.


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  • Indirect Wastes  -  Waste pipe used to convey gray water by discharging it into a plumbing fixture such as a floor drain.
  • Instantaneous Water Heater  -  A type of water heater that heats water as it flows through a heat exchanger coil.
  • IPS  -  Iron pipe size


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  • Jet  -  An orifice or other feature of a toilet that is designed to direct water into the trapway quickly to start the siphon action.
  • Johnni-Bolts  -  Closet bolts, used to mount the toilet bowl to the closet flange.


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  • Knockout Plug  -  PVC test plug.


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  • Lavatory  -  A fixed bowl or basin with running water and drainage for washing.
  • Leach Field  -  Porous soil area, through which septic tank leach lines run, emptying the treated waste.
  • Leader  -  Pipe carrying rainwater to the ground or sewer.
  • Leakage  -  During a service run of a water softener, a certain amount of hardness exits the resin bed with soft water.  This is what leakage is.  Leakage occurs as a result of hardness ions being left in the bed or by channeling the water through the resin bed.
  • Liquid  -  Having a specific volume and can hold any shape it is contained within. 
  • Lock Nut  -  Nut fitted into a piece of pipe and screwed onto another pipe to join the two pieces.


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  • Main  -  The primary artery of supply of the water supply or drain system in which all the branches connect.
  • Male Thread  -  Threads on the outside of pipes and fittings.
  • Malleable Fitting  -  Fitting made of metal which is soft and pliable.
  • Manifold  -  A fitting that connects a number of branches to the main.
  • Mechanicals  -  The wiring, plumbing and heating and cooling systems in a building, including the components with moving parts.
  • Multi-stage Pump  -  A pump that has more than one impeller.


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  • Nipple  -  A short length of pipe installed between couplings or other fittings.
  • No-hub  -  A connector for no-hub iron pipe consisting of a rubber sleeve and a stainless steel band secured by hose clamps.
  • Nominal Pipe Size  -  The external size diameter designated of pipe or threads.


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  • O-ring  -  Round rubber washer used to create a watertight seal.
  • Oakum  -  Loosely woven hemp rope that has been treated with oil or other waterproofing agent.  It is used to caulk joints in a bell and spigot pipe and fittings.


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  • Packing  -  Fibrous material that is used on faucets to prevent leaks.
  • Packing Nut  -  Nut that holds the stem of a position and holds the packing material.
  • Peak Hour Demand  -  Time when the largest demand for hot water is needed.
  • Pipe  -  A hollow tube that can carry products such as fluid, gas, granular and more.
  • Pipe Dope  -  Slang for pipe-joint compound.
  • Pitch  -  Downward slope of a drain pipe in the direction of the water flow.
  • Plumb  -  Precisely vertical.
  • Plumber's Putty  -  Pliable, popular putty used to seal joints between drain pieces and fixture surfaces.
  • Plumbing Tree  -  Prefabricated set of drain waste, vent, and supply lines.
  • Plunger  -  Deals with drain clogs of all kinds.
  • Pop-up Drain  -  Type of drain assembly for lavatory and bath.  When a lavatory lift rod or bath operflow lever is lifted, the pop-up drain closes so the lavatory or tub retains water.
  • Port  -  An opening in a burner head through which gas or an air-gas mixture is discharged for ignition.
  • Positive Displacement Pump  -  Called a PD pump.  Gear, sliding vane, progressive cavity, lobe, etc.  The capacity determined by the pump speed.
  • Potable  -  Denotes whether a water is suitable for human consumption.
  • Pottable Water  -  Denotes whether water is suitable for human consumption.
  • Pressure  -  It is the force exerted perpendicular to the surface of an object and is expressed as force per unit area.
  • Pressure Differential  -  The pressure difference between two points of a system.
  • Pressure Loss  -  The difference in upstream and downstream pressure.
  • Pressure Balance Valve  -  Shower mixing valve that automatically maintains balance between incoming hot and cold water supplies by immediately regulating fluctuationsin pressure.
  • Pressure Tank  -  A device used to pump water from a well.
  • Pressure Tubing  -  Tubing used to conduct fluids under pressure or at elevated temperature or both, and produced to stricter tolerances than pipe.



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  • Rate Storage Volume  -  Quantity of water stored in a tank.
  • Reamer  -  A gringing  tool used to level or remove burrs from valve seats in faucets so that the valve stem will fit properly.
  • Recovery Capacity  -  The amount of water in gallons per hour, raised 100 degrees F at a given thermal efficiency and BTU per hout input.
  • Reducer  -  A fitting that connects pipes of different sizes togeather.
  • Return Circulation System  -  Tempered water from or near the point of usage which eliminates waste of hot water used for long runs and adds storage to the system.
  • Revent  -  Pipe installed specifically to vent a fixed trap.  Connects with the vent system above the fixture.
  • Reverse Trap Water Closet  -  A water closet having a siphonic trapway at the rear of the bowl, and integral flushing rim and jet.
  • Rigid Pipe  -  Pipe designed to transmit the backfill load to the foundation beneath the pipe.  Rigid pipe must be supported on the bottom portion of the pipe.
  • Rim Holes  -  A series of small holes in the underside of a toilet rim, around the circumference of the bowl.
  • Riser  -  A vertical metal or plastic tube or assembly that connects a faucet to the water supply stop valve.
  • Roof Flushing  -  Sheet metal installed at any break in a shingled roofline to prevent links.
  • Rough-in  - Installation of the drain, waste, vent, and supply lines in a structure to the proposed location of each fixture.
  • Rough-in Dimensions  -  The distance from a finished wall or floor to the center of the waste or supply opening or mounting boles on a plumbing fixtures.
  • Run  -  A complete or secondary section of pipe that extends from supply to fixture of drain to stack.


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  • Service Classification  -  A service classification or service class is a one to three letter designation that shows what service the line is in.
  • Saddle Valve  -  A valve mounted on a pipe run by a dampening device, or fitting that taps into the side of the pipe, used to make a quick connection to an existing line to provide a water supply for a low demanding device.
  • Sanitary Sewer  -  House drain that carries wastewater away from the house to a sewer system or septic tank.
  • Self-rimming Sink  -  Sink with no metal ring that has a built-in lip of the same material which supports it in the vanity top.
  • Septic System  -  An underground wastewater collection and treatment system.
  • Septic Tank  -  A partitioned underground piece of equipment for sewage collection and treatment.  The wastewater is then releases into the ground through a leaching line or system.
  • Service Entrance  -  Pipe connecting the water company piping to the water meter.
  • Shroud  -  Color-matched component under a wall-mount lavatory that coveres the drain outlet for aesthetic purposes.
  • Siphon-vortex Water Closet  -  A toilet having a trapway at the rear of the bowl, integral flushing arm, and a water supply with or without a jet, which does not feed directly into the trap.
  • Sleeve  -  Pipe which is passed through a wall for the purpose of inserting another pipe through it.
  • Slip Joint  -  A connection made with compression fittings.
  • Soil Stack  -  Large vertical drain line to which a branch waste line connects.
  • Solder  -  Metal alloy that is melted to create a flush joint between metal pieces.
  • Spud  -  A threaded opening on the water heater tank.
  • Stack  -  The vertical main in the drain, waste, and vent system, extending one or more stories.
  • Stand Pipe  -  Open vertical pipe that receives water from a washing machine.
  • Static Lift  -  The vertical distance between source and discharge water levels in a pump installation.
  • Stop Valve  -  The shutoff valve under sinks and toilets.
  • Straight Cross  -  Fitting that connects four pipes of the same diameter.
  • Stress  -  The force per unit area of cross-section.
  • Sump  -  A pit, or pool for draining, collecting, or storage water.
  • Sweating  -  Slange term for soldering.


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  • T&P Valve  -  Temperature & pressure relief valve.  A safety device used to expel excess heat or pressure from the tank.
  • Tailpiece  -  Section of pipe that runs between a fixture outlet and application.
  • Tail Pipe  -  The pipe added below the jet assembly, in a weak well application.
  • Tank  -  Fixture resivoir for flush water.
  • Tank Ball  -  The moving part of the flush valve that seals water in or allows water out of the tank during the flush cycle. Also known as the flapper, flush ball, stopper and seal disk.
  • Tank Bolts -  Three bolts that hold together the tank, gasket and bowl of the toilet.
  • Tank Cover Lock  -  Device to prevent damage to and removal of the toilet tank cover and contents of the tank.
  • Tank Cross  -  A double tee shaped fitting installed between a shallow well pump and the bladder tank with integrated valve and gauge fittings, and an outlet for a pressure relief valve.
  • Tank Level  -  The toilet tank water level.
  • Tap  -  Tap is synonymous with faucet.  Also tap refers to the divergence of water from one fitting to another.
  • Tap Tee  -  Cast iron tee with a threaded female side inlet.
  • Thermal Efficiency  -  The fraction of heat that is converted to work or desired output divided by required input.
  • Trap  -  Curved section of drain line that prevents sewer odors from escaping into the atmosphere.
  • Trap Arm  -  The waste arm portion of a drainage trap.
  • Trap Drip  -  The U-bend portion of a drainage trap.
  • Trap Primer  -  A small feeder line connecting the cold water line directly to the drainage trap, which releases a small amount of water to the trap should it run dry to maintain the water seal.
  • Trap Seal  -  It provides the water seal which prevents sewer gasses from entering the home.  It is measured from the top of the dam down to the inlet of the trapway.
  • Trip Lever  -  Flush handle and actuating arm on a toilet tank.


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  • Uni-flex  -  One piece stop and riser combination.
  • Union  -  Three piece fitting that joins two sections of pipe, but allows them to be disconnected without cutting the pipe.
  • Usable Storage  -  Percentage of hot water that can be drawn from a tank before the temperature drops to a point that it is no longer considered hot.


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  • Vacuum Breaker  -  An anti-siphon device that prevents the backflow of contaminated water into the water supply system.
  • Valve  -  A mechanism used to stop or open and regulate flow.
  • Valve Dressing  -  Resurfacing a worn valve seat with a special tool.
  • Valve Seat  -  The non-moving part of a valve.
  • Vapor  -  The gas state of a liquid or solid.  Both vapor and gas are basically the same thing.
  • Velocity  -  The rate of change or displacement with time.
  • Vent  -  A pipe that allows air into a drain system to balance the air pressure, preventing water in the traps from being siphoned off.
  • Vent Header  -  A vent pipe into which several vents connect.  The vent pip leads to the vent stack and out of the building.
  • Vent stack  -  Upper portion of the soil stack above the topmost fixture through ehich gases and other odors escape.
  • 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.
  • Viscosity  -  The measure of the internal friction/resistance to the flow of a liquid.
  • Vitreous China  -  Ceramic materials fired at high temperature to form a non-porous body, having exposed surfaces coated with ceramic glass fused to the body.
  • Volumetric Flow Rate  -  The amount of fluid that flows in a given time past a specific point.


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  • Washdown Water Closet  -  Water closet having a siphon trapway at the front of the bowl, and integral flushing rim.
  • Wash Arm  -  Drain extension pipe, usually to extend a sink drain into a wall.
  • Waste & Overflow  -  Drain assembly for the tub.
  • Water  -  Can exist in three of the four phases of matter: gas, liquid, or solid.
  • Water Closet  -  Where you will find the toilet.
  • Water Hammer  -  Occurs when a valve is suddenly opened or closed.
  • Widespread  -  A type of bathroom lavatory faucet having separate spout and handle, usually 8" from center of handle to handle.
  • Working Pressure  -  The normal pressure that a system operates at.



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  • Yoke  -  Usally a brass casting that holds both the hot and cold valves and the mixing chamber for the water.


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Tags: Mechanical Pipe Pipe Fitting Valve Engineering