100 Words Every Plumber Should Know

No.	Term	Definition
1.	ABS pipe	Black plastic drain pipe material.
2.	Adapter	Fitting joining different pipe sizes or types.
3.	Air admittance valve	One-way vent valve; admits air, blocks sewer gas.
4.	Angle stop	Shutoff valve under sinks and toilets.
5.	Anode rod	Sacrificial rod preventing water heater corrosion.
6.	Anti-siphon valve	Prevents backflow by stopping siphon action.
7.	Backflow	Reverse flow contaminating potable water.
8.	Backflow preventer	Device stopping reverse flow into supply.
9.	Ball valve	Quarter-turn shutoff valve with ball.
10.	Barbed fitting	Fitting for flexible tubing with ridges.
11.	Basin wrench	Tool for tightening faucet nuts.
12.	Bell trap	Floor drain trap with removable bell.
13.	Black iron pipe	Steel pipe used for gas lines.
14.	Blowout plug	Plug sealing drain line for testing.
15.	Booster pump	Pump increasing water pressure.
16.	Branch drain	Horizontal drain serving multiple fixtures.
17.	Brass nipple	Short threaded brass pipe section.
18.	Cleanout	Access opening for clearing drain blockages.
19.	Code	Regulations governing plumbing installation and safety.
20.	Compression fitting	Seal using ferrule tightened by nut.
21.	CPVC	Chlorinated PVC for hot and cold water.
22.	Cross-connection	Link between potable and nonpotable systems.
23.	Dielectric union	Fitting preventing galvanic corrosion between metals.
24.	Dip tube	Directs cold water to tank bottom.
25.	Drain snake	Flexible auger for clearing clogs.
26.	Drainage slope	Pitch ensuring proper gravity flow.
27.	DWV	Drain, waste, and vent system.
28.	Eductor jet	Venturi nozzle in some pumps.
29.	Effluent	Liquid wastewater leaving a system.
30.	Elbow	Angle fitting changing pipe direction.
31.	Escutcheon	Decorative cover plate around pipe penetration.
32.	Expansion tank	Absorbs thermal expansion in closed systems.
33.	Fernco coupling	Rubber coupling with clamps for repairs.
34.	Fixture unit (FU)	Load measure for plumbing system sizing.
35.	Flange	Rim fitting; toilet flange mounts toilet.
36.	Float valve	Valve controlled by float level.
37.	Flow rate (GPM)	Water volume delivered per minute.
38.	Flushometer	Valve for commercial toilet or urinal flushing.
39.	Frost-free sillcock	Outdoor faucet designed to resist freezing.
40.	Gate valve	Multi-turn valve with rising gate.
41.	GFCI	Shock-protection electrical outlet near water.
42.	Grease trap	Interceptor capturing fats, oils, and grease.
43.	Hammer arrestor	Device reducing water hammer shock.
44.	Hanger	Support bracket securing pipe runs.
45.	Heat trap	Check fitting reducing water heater heat loss.
46.	Hose bibb	Exterior faucet with hose threads.
47.	Hub	Socket end of cast-iron fitting.
48.	Hydrostatic test	Pressure test using water.
49.	Impeller	Rotating pump part moving water.
50.	Interceptor	Device separating solids or grease from waste.
51.	Isolation valve	Valve shutting off a section for service.
52.	J-trap	Curved trap under sinks preventing sewer gas.
53.	Jet pump	Pump using jet assembly to lift water.
54.	Joint compound	Pipe dope sealing threaded connections.
55.	Key stop	Recessed shutoff operated with a key.
56.	Kitchen sink strainer	Basket fitting connecting sink to drain.
57.	Knife valve	Sliding gate valve for wastewater.
58.	Lacquer thinner	Solvent used for cleaning some surfaces.
59.	Lavatory	Bathroom sink fixture.
60.	Lead-free	Meets limits for lead in wetted parts.
61.	Leak detector	Sensor identifying water leaks.
62.	Main shutoff	Primary valve stopping building water supply.
63.	Manifold	Header distributing water to multiple lines.
64.	Meter coupling	Fitting connecting to water meter.
65.	Mixing valve	Blends hot and cold to set temperature.
66.	Nipple extractor	Tool removing broken threaded pipe.
67.	No-hub coupling	Shielded coupling for cast-iron DWV.
68.	Nominal size	Named pipe size, not exact measurement.
69.	NSF/ANSI 61	Standard for potable water contact materials.
70.	O-ring	Rubber seal ring for joints.
71.	Offset flange	Toilet flange shifting centerline slightly.
72.	Overflow	Secondary outlet preventing fixture overfilling.
73.	P-trap	U-shaped trap blocking sewer gases.
74.	PEX	Flexible cross-linked polyethylene water tubing.
75.	Pipe cutter	Tool cutting copper or plastic pipe.
76.	Pipe dope	Thread sealant compound for fittings.
77.	Plumber’s putty	Malleable sealant for drains and fixtures.
78.	Pressure regulator	Valve reducing incoming water pressure.
79.	PRV	Pressure-reducing valve; controls supply pressure.
80.	Pump check valve	Prevents pumped water from flowing backward.
81.	Quick-connect fitting	Push-fit connector for tubing.
82.	Reducer bushing	Threaded fitting reducing pipe size.
83.	Relief valve (T&P)	Safety valve releasing excess temperature or pressure.
84.	Riser	Vertical pipe section.
85.	Rough-in	Initial installation of concealed piping and drains.
86.	Saddle valve	Clamp-on piercing valve; often discouraged.
87.	Sanitary tee	T-fitting directing waste into vertical drain.
88.	Septic tank	Onsite wastewater treatment and settling tank.
89.	Sillcock	Outdoor faucet assembly.
90.	Slip joint	Tubular drain joint tightened by nut.
91.	Solder	Metal alloy used to join copper pipe.
92.	Solvent cement	Adhesive fusing PVC/ABS joints.
93.	Stopper	Plug closing a drain opening.
94.	Strainer	Screen catching debris in drains.
95.	Sump pump	Pump removing groundwater from a sump pit.
96.	Teflon tape	PTFE thread tape for sealing.
97.	Tempering valve	Mixing valve limiting hot water temperature.
98.	Trap primer	Adds water to traps to prevent drying.
99.	Union	Detachable fitting allowing easy disassembly.
100.	Vacuum breaker	Prevents backsiphonage at hose connections.