Your Complete Guide to All Things Plumbing

James P. Gorman, Chief Executive Officer and Chairman of Morgan Stanley investment bank, once said: “If you consider the contribution of plumbing to human life, the other sciences fade into insignificance.” 

Plumbing as a trade is one of the oldest, and as a system is one of the most important in the daily life of society. Here in the United States, most people wake up, get out of bed and immediately use the shower, the sink, the toilet. They use the dishwasher or throw their laundry in the washing machine several times a week. Now think beyond using fixtures in the home. Water is used in the mass production of food and goods, filtered for drinking, a source of power, and is corralled, redirected, and recycled for countless other uses. Water truly is life, and, with that notion, plumbers hold our lives in their hands.

SUPPLY.com is a plumbing supplier of all the goods – finished fixtures, replacement parts, tools. We understand and celebrate the value of the plumber and the proper application of knowledge that must come with the job to keep our dear systems in place. In this guide, we’ll discuss the basics of plumbing, how to get into the trade, and tips to keep in mind.

Plumbing Basics

Archaeologists have dated plumbing all the way back to 4000 B.C. in several ancient regions including Egypt, the Indus River Valley, and China. The term “plumber” stems from plumbum, the Latin word for lead. Indoor plumbing has been common in households for over a century. Piping and water systems are nothing new, and they’ve been developed over thousands of years into what you see today.

Common Plumbing Issues

The main uses of plumbing are potable water, sewage removal, and heating & cooling purposes. Plumbers are tasked with a variety of jobs pertaining to these purposes. Later in this guide we’ll go over the different jobs in the field and what all a plumber can do, from large-scale installs to smaller home repairs. Before we get into that, though, some of the main reasons plumbers are called on the job are listed below.

Dripping Faucets

Once a faucet starts dripping repeatedly, it becomes really noticeable and frustrating. It can also be wasteful of water or indicative of a larger issue going on. A dripping faucet may mean there needs to be a replacement, or it may be a simple fix, but it usually takes a plumber to solve the issue.

Clogged Drains

Another one that’s usually a simple fix, but sometimes too far out of the homeowner’s hands. Plumbers can spend a lot of time snaking clogs out of drains or figuring out a deeper issue that may be causing the pipes to back up.

Low Water Pressure

Low water pressure could be due to several things going on with a plumbing system, like a clog, leak, blockage, or broken pipe. It can be hard to tell what’s going on without looking deeper, so it’s often necessary for a plumber to run a diagnostics test to find and fix the issue.

General Maintenance

Homes and businesses need maintenance, both preventive and reactive. Plumbers can make sure the water heater is working, the pipes aren’t corroding, and check for leaks, just to name a few tasks.

These are just a few common problems plumbers face, but they’re called on for a number of other problems or emergencies. Some plumbers don’t fix things but focus on new installs instead, and some work with larger-scale pipes outdoors. Either way, they’re the go-to guys and gals when it comes to all things water.

Plumbing Subsystems

A home has two subsystems that carry water both in and out of the house. The water supply system flows inward, while the drain-water vent system flows water outward.

The water supply system that flows into the home is sourced either from well water or city water. For those on city water, the water typically comes from a giant underground pipe, while well water is pumped from an underground well system. High pressure in the pipes allows the water to travel around the house and into upstairs rooms.

Fixtures, like a sink, have water flowing both in and out. The drain-water vent (DWV) system consists of drain pipes, drain traps, and drain vents. Drain traps, also known as p traps, hold water and allow debris to travel down through the pipes without clogging. The drain vent allows air into your system to make the flow of water smoother and more consistent. The drain pipes are larger and more complex than pipes in the water supply system, and they need to be strategically built with gravity and the downflow of water in mind.

Kitchen Plumbing System

Most kitchens are centered around the sink. There may also be a dishwasher, garbage disposal, ice maker, and gas stove with gas supply pipe. Most of the plumbing is kept underneath the kitchen sink, and consists of the main pipes and parts needed for the water supply and drainage systems.

Bathroom Plumbing System

The bathroom is usually the first place that comes to mind when you think of plumbing. It’s majorly important to bring water into the bathroom, and definitely to make sure that water gets drained back out (read: toilet water). There’s a sink, shower and / or tub, and toilet in the bathroom. Cold water comes in from the water supply system. At the water heater, hot water is separated and comes into the bathroom from a different line.

The Water Heater

Speaking of the water heater, it’s a pretty important fixture. There are tank water heaters and tankless, narrowed down further by gas and electric. “Tank vs tankless” is a debate in the industry, with tankless heaters as the energy-and-space saving, instantaneous-water, newer, more expensive option that some plumbers and homeowners still aren’t on board with. As far as the function of the water heater, regardless of type, cold water enters and is heated to spread throughout the home or facility. A residential or repair plumber will see a lot of water heaters throughout their career, often called to fix or replace and also as a part of routine maintenance. Water heaters need to be flushed once or twice a year, but it’s typically a simple procedure a homeowner can do without a plumber.

Plumbing as a Trade

plumbing trade levels plumbing apprenticeship

Most plumbers enter the trade within a few years of graduating high school, though any adult with a high school education or GED can start plumbing at any time. There are several approaches to starting the trade, and, from there, several different types of plumbing jobs. In the sections below, we go over the process to become a plumber and the options open within the field.

How to Get into Plumbing

Start with technical training. You can find plumbing classes at your local trade school or college to get your vocational training. Next you’ll start on your apprenticeship. One of the big perks of becoming a plumber is that apprenticeships typically pay a wage as you’re learning the trade – oftentimes, you’ll work as an apprentice and do your schooling at the same time.

To look for an apprenticeship, start asking around local plumbing companies to look for a licensed plumber to take you on. Some states have programs to apply for starting jobs, or you can look into going the union route.

Plumbing Job Levels

After completing your apprenticeship, you’ll be a journeyman plumber. The journeyman knows how to do most of the job on their own, but works under the guidance of a master plumber. After about two years or a certain amount of hours as a journeyman plumber, you’ll take another exam to get certified as a master plumber.

Types of Plumbing

At a basic level, there are three types of plumbers: commercial, residential, and service & repair.

Commercial Plumbing

Commercial plumbers work on the installation and repair of large-scale facilities. They aren’t the ones you call to fix the running toilet in your home or to install a new showerhead. Instead, they’re the ones working on airports, gyms, or office buildings. A commercial plumber can work with both inside and outside plumbing systems, from water heater installations to running sewage lines.

Residential Plumbing

Residential plumbing involves more work in individual homes and on individual systems. Residential work is usually on the typical 8-hour workday schedule, whereas commercial plumbing can be done at all hours, and is often completed when most people aren’t working or driving on the roads.

Service & Repair Plumbing

Service & repair plumbers are not working on new installs. Their days look different, always fixing a new problem. A service & repair plumber responds to calls for broken plumbing systems or routine maintenance, and can work in a residential or a commercial setting.

All Plumbing Professions

In addition to plumbers, there are other similar jobs in the trade like pipefitters, pipelayers, and steamfitters.


Plumbers install and maintain the systems we’ve discussed in this article. They work with setting up water flow towards a building and everything that involves, from showers to toilets to dishwashers. They also work with all the drainage and water coming out of a structure. A plumber can work for a plumbing company, own a plumbing company, work as a contractor, and, depending on location, can join a union.

Pipefitters & Steamfitters

Pipefitters and steamfitters fall under the same trade, but are categorized differently by the material they work with. While pipefitters typically transport both high- and low-pressure water systems, steamfitters exclusively work with gases and liquids under high pressure. The job of a pipefitter/steamfitter is more closely related to that of a welder than that a plumber. They can work for an HVAC company, building company, utility company, hospital, chemical plant, or a number of other industries.


Pipelayers lay different materials of pipe for several purposes, including sanitation, stormwater systems, and other big-picture purposes of water. Pipelayers must know the technical applications of pipe structure, as well as be able to dig trenches and weld / glue pipe together.

Tips, Tricks, & Frequently Asked Questions

plumbing trade tips how to become a plumber

You may like the idea of being a plumber – you like working with your hands, solving problems, and having job security. Still, it can be hard to know what a job is actually like before you’re in it. In this section, we have some tips for getting started, intel into the daily life of a plumber, and answers to frequently asked questions about working in the trade.


Do I need to have any experience before training to become a plumber?

Nope! That’s what all the training is for. It doesn’t matter how old you are, though of course you’ll need to be old enough to have a high school diploma and legally be allowed to work.

Is plumbing hard work?

Definitely, but most plumbers will tell you it’s worth it. Take care of yourself and be safe early on, because plumbing will take a toll on your body throughout the years.

Most plumbers I see are male – should I go into plumbing as a female?

Of course, go for it.

How do I know if plumbing is right for me?

Like most things, you’ll never completely know if something is right for you until you try it. But if you like working with your hands, solving problems, and don’t want to work in an office, it’s likely that plumbing could be a good fit for you.

A Day in the Life

plumbing daily schedule

A big appeal of the trade for a lot of people is that plumbing can vary day-to-day. Depending on the job type a plumber has, they may be called in to fix a toilet one day and install a shower the next, or they may work on a big build for a longer period of time. Most plumber’s days start early in comparison to the rest of the world, and some are even on call 24/7.

A typical day, no matter the type of work the plumber does, will start off with heading to the office or checking their phone / email for appointments at home. They’ll likely already have a job lined up – maybe someone called the day before with a leak, or they’re heading to a construction site to continue an install. Or maybe they’ll get a call the day of and head out from there.

The next task is to check the truck to make sure they have all the necessary parts, coordinate with other employees depending on the size of the company, and get to work.

Depending on the length of the first job, the plumber will likely squeeze in a few more that day. The job of a plumber can require a lot of driving, which is something to consider in a traffic-heavy city, but not a deal-breaker for most of those in the trade. In addition to driving around to jobs, they may need to also stop by the supply store to pick up any extra parts that the job requires.

At the job itself – this scenario applies mostly to residential / repair plumbers, or someone working on a small commercial job – the plumber will check out the problem, give the customer a quote, and start work once they get the go-ahead. They day ends around 5 pm, but often runs overtime because a job turns out to be more complicated than it initially seemed. The plumber heads home, gets some rest, and does it all again the next day.

Tips for Anyone Starting out in the Trade

We spoke with one of our customers, John Castro, to get his take on tips for newbies to the trade. If you’re sold on plumbing, take this advice from a real plumber.

“I was an insurance agent one week and a plumber the next.”

After 18 years working in the insurance industry, John Castro decided to become a plumber after remodeling his own house. He enjoyed helping out the plumber he hired for the remodel and was invited to come along on another plumbing job – he quit insurance soon after, and he’s never looked back.

As a plumber in the Studio City neighborhood of Los Angeles, John has had an enjoyable and profitable career. His son Chris, who we spoke with in our blog post “SUPPLY.com’s Coolest Jobs,” works alongside his father at John Castro Plumbing and has been a customer of Account Manager Robyn Whitcomb at SUPPLY.com for years. In this article, John offers advice for anyone looking to start their own business in the plumbing trade.

1. It takes common sense, hard work, and honesty

These three values are the most important ingredients in the recipe for success, according to John. It was an “honesty first” mentality that set John up to make fast friends with his customers and to get repeat business. Visiting different homes every day and talking with new people has been his favorite part of the profession. Living in Los Angeles, he became a “plumber to the stars,” even working in the homes of customers like Sylvester Stallone!

2. Always save a little bit

“If you make 10 bucks, put a dollar away. If you make 100 bucks, put 10 dollars away. And so on.” If you’re starting a business, you’ll need to have enough money to begin with in order to survive. Once you take off, remember to still always save a little bit at a time. Throughout his lucrative plumbing career, John was able to work for all the money he could’ve wanted, lived in a nice home, and put his kids through school. Now, as people choose universities over trades and the skilled labor shortage grows, there’s an opportunity to get paid very well as a plumber.

3. Advertise everywhere you can

One of John’s main pieces of advice to anyone starting out is to just get your name out there. When he started in the 1980s, he put an ad for his plumbing services in the Greenpages and started getting calls. Pay for advertising, he says, but anytime there’s a chance for free publicity take it. One trick he has up his sleeve: take different a route home each night. The more people who see your truck with the company name on it, the more people will keep you in mind as the plumber to call.

4. You don’t need many tools, just the important ones

Eventually, with the money you save, you can buy more and build your collection. Start out with your hand tools and soon enough you’ll be able to afford more expensive ones – “all you really need for 90% of jobs is a channellock in your back pocket,” John says, though over the years he has accumulated quite an assortment of tools. “If a plumber out there needs any tools he can come to my garage and take some off my hands!” John quipped during our interview.

5. Always work with a helper

“I always worked with a helper – just in case.” One time, John was working in a home that had the dryer from the laundry room vented underneath the house. Lint from the dryer caught fire and John couldn’t get it out – without his helper the situation would have quickly turned into a disaster.

6. Keep your head up, learn new things, and be a nice guy

“Treat your business right and it will treat you right.” For John, it’s been simple. Put effort into your work and treat people right, and your business will get a good reputation. As a plumber, you’re helping people every day – John remembers during the 1994 Northridge earthquake, he parked his truck in the middle of the street and there was a line of people down the block who needed plumbing repairs from the damage. It’s a good feeling to know that you’re lending a helping hand and to thoroughly enjoy your job. It’s hard work, but as John can attest, it pays off.

Tips for the New Plumbing Apprentice

Already decided that plumbing is for you and landed your first job as an apprentice? Congratulations! Below are few tips to look over to get prepped for the job. 

1. Be on Time

This is good advice for any job or appointment, but it’s essential for you as an entry level plumber to be organized before starting the workday by getting your tools together and thinking about the tasks on your plate. If you’re late to the first job site, you’ll probably be late to every job site thereafter. Plus, being early is a major sign of respect to your new peers.

2. Ask Questions

Your boss knows you’re new and doesn’t expect you to know everything. It’s okay to ask consult your employer and questions; it’s actually heavily encouraged! Make sure you pay attention and write down anything you won’t remember. Don’t ask too many questions in front of a client if you can help it, though – they may not realize you’re a new plumber apprentice and wonder if they hired the right person to install that Elkay sink (check out this guide to building a kitchen sink with Elkay to make sure that never happens!).

3. Put Down the Phone

Just like when you’re sitting at the dinner table, this is a sign of respect. Aside from being polite, putting your phone away will help you stay focused. You’ll be learning a lot and working with your hands, so it’s important that you’re completely alert. The Gram can wait.

4. Buy Cheap, Buy Twice

Quality plumbing tools are vital on the job, and they aren’t always cheap. Buy at least one tool with every paycheck and you will build up a top-notch collection in no time. It may be tempting to buy the less expensive stuff, but you’ll thank yourself when you don’t have to rebuy pipe wrenches every six months.

5. Tape, Marker, Level

Speaking of tools, there are three you should always have on hand. If you bring these on your first day, you’ll impress your boss and be ahead of the game. Come prepared with a tape measure, a marker, and a level. It doesn’t hurt to have quality knife and a set of pliers too.

6. Protect Your Body

You’ll thank us, and yourself, for this one later. If you’re young and spry, it may not seem like a big deal to have cheap, uncomfortable shoes or to help out by carrying an extra load. But as a physical job, you can wear your body out quickly. Get comfortable boots, use knee pads, and get plenty of rest. Stretch before or after work to help prevent back pain. You don’t want to end up unable to do the job you spent so much time learning how to do!

7. Don’t Stand Around

Last but not least, clean up your surroundings or offer to lend a hand if you ever need something to do. Standing around will make you appear lazy (especially if you’re on your phone!). Keep your hands out of your pockets and look busy even when it’s slow. Try to anticipate what needs to be done next so that you can help. Aside from appearances, it will actually speed up the job if you can get ahead with the menial tasks.

Plumbing Glossary

We’ve covered the basics of the trade, but if you want to learn more or reference a term, check out the glossary below. 


Acrylonitrile butadiene styrene. A pipe material often compared to PVC.

Accepted Engineering Process

The standard procedure in plumbing that is widely recognized and accepted. 

Access Cover

A temporary cover for a pipe or fitting, removable for maintenance or inspection. 


A heat-activated plastic coating used primarily on bathtubs. 


Americans with Disabilities Act. Regulations to ensure accessibility for all users, like toilet height specifications. 

Adapter Fitting

A fitting that is used to connect pipes that are not of similar material or size. 

Administrative Authority

The governing unit or the commissioner of labor for the region. 


American Gas Association rating. 

Air Admittance Valve

Allows air to enter pipe, which equalizes the pressure within. 

Air Break

The space between the drainage system and the end of the system below flood level. 

Air Conditioning

System that controls the air flow and ventilation in a space, usually for the purpose of cooling the temperature. 

Air Shutter

Controls the amount of air mixed with gas for combustion; adjusts the amount of air allowed to flow through an inlet. 

Alternative Engineered Design

Made differently than the standard design but with the same intention and performance level 

Angle Stop

A small valve used to connect a pipe that changes direction at an angle. 

Anode Rod

Part of a water heater used for electrolysis, the anode rod is a rod wrapped in metal that protects the exposed steel of the heater. 


American National Standards Institute. Recommends and certifies the standards of a process. 


Blocks the flow of water that isn’t potable into a drinking system. 


Someone learning the plumbing trade and working under the guidance of a licensed plumber.


A pump that suctions out fluids or gases.

Automatic compensating valve

With access to both cold and hot water, it maintains water temperature to an outlet. Used to reduce scalding and extreme temperatures. 

Automatic Gas Shutoff Device

Cuts off the gas supply. Typically used during emergencies or preventatively to reduce risk during maintenance. 

Back Flush

Purposeful reverse the flow of water temporarily.


Unwanted reverse flow of water that can cause contamination. 

Backflow prevention device

Redirects flow of water so it can’t flow back in the same direction, causing backflow and the contamination of drinking water. 


An object placed in a plumbing fixtures that stops or changes the flow of water.

Ball Passage

The size of a toilet trapway. Refers to the size ball that can pass through the trapway. 


Part of the toilet tank that facilitates the flow of water, simultaneously preventing backflow or overflow. 


An open design that allows for easy access within the bathroom, especially to the toilet. 

Base flood elevation

Calculated to determine at which level of the base a flood indicates risk. 


The bowl portion of a sink where the water gathers before draining. 

Basket Strainers

Catches solids that are unintentionally in a liquid. Has a screen to clean out and remove waste. 


A room usually containing a toilet and sink, and often a shower or bath. 


A faucet with the hose turned downwards.


A plumbing fixture next to or attached to the toilet that uses the flow of water for bodily cleaning after using the toilet.


A finish that is a slightly warmer and darker version of white. Very common in plumbing fixtures, as it can be hard to maintain the appearance of a white finish. 


Wastewater from toilets, considered unhealthy and dangerous. 


Water is heated and used for warmth or other purposes, like santitation. 


Any part of a plumbing system that is not the main line. 


A finish and material that combines the colors of gold and brown. It is an alloy of copper and zinc and is often used to avoid sparking. 


Similar to soldering, brazing is the making of a joint using heat over 450° C or 840° F.

British Thermal Unit (BTU) 

The amount of heat required to raise the temperature of one pound of water by 1° F.

Buchan Trap

A trap located in domestic sewage systems to prevent the passage of odors further into the system and into the attached structure.

Building Drain

Receives the remains from other drainage pipes outside of buildings and facilitates flow to the sewer. 

Cast Iron

A piping material that has been used for centuries. 


When faucet holes in a counter are installed 4 inches apart, and a combination faucet with handles and spout is installed.

Central Furnace

A gas-burning appliance made to heat an area using combustion through metal and transferring to the area.


A material used for many plumbing fixtures, especially bathroom sinks and toilets. Made from clay and water fired with a glaze coating. 


A container for holding liquid. 


A pipe with a drain cap. Connects to the drainage system, and the cap can be removed to clean out debris from the system. 

Close-coupled toilet

The cistern is mounted on top of the toilet bowl, meaning the whole fixture is connected as one unit. 

Closed water piping system

Water flows in through a supply line, but flows out through a separate drain or sewage line. 


Referring to water closet. Another term for toilet. 

Closet auger

Also known as a plumbing snake. A device that is usually made of a long piece of metal that can reach deep within a drain to clear a clog. 

Closet bend

Part of the drainage system underneath a toilet – the curved section of pipe attached to the waste pipe. 

Closet Flange

Also known as a toilet flange. Connects the toilet to the drain pipe in the floor. 


Regulations of plumbing systems that are used to determine if a design or installation passes inspection. 

Combination fixture

Combines toilet, sink, and drinking fountain. The water and waste connections are both made through the floor, for buildings without a way to hide the wall pipes. 

Combination waste and vent system

A combined horizontal piping system beneath the floor drain or sink to carry waste out and allow air flow. 

Combustible Construction

Materials connected to or nearby heating appliances, like a hot water pipe


Burning; a chemical reaction between a fuel and an oxidant


Another word for toilet; the fixture in the bathroom for defecation and urination

Concealed fouling surface

The area of a fixture which is not visible and is not cleansed


Water that forms from steam and must be removed from the lowest point of a piping system

Condensing furnace

A high-efficiency furnace that maximizes energy. Condenses and heats gases instead of wasting additional heat by letting it escape.


An internal pipe that carries water from the roof to a drain

Confined space

Limited room for entry and not intended for ongoing occupancy

Construction documents

The design plan for the construction of a structure, made with code requirements in mind and presented to the plumber for direction


Commonly used piping system for water or HVAC system; classic choice that is now often compared with PEX (plastic) systems


A plumbing fitting that fits over the outside of two pipes. Can be joined or soldered to keep the pipes together.


Chlorinated polyvinyl chloride. Pipe material known for its flexibility and usefulness when it comes to transporting both extremely hot and extremely cold water.

Cross connection

A system setup or connection between potable (drinking) water and contamination


Cold water


Cold working pressure


Copper water tube


Copper by copper. A fitting that works with copper pipe.

Dead end

A closed pipe that does not lead to another pipe or system.

Depth of water seal

Where waste pipes discharge, a trap exists creates a seal to prevent waste from returning through the pipe to the building. Must be at least 75mm deep.

Developed length

A measurement taken along the center of a pipe, including any attached fittings.


Natural or artificially induced. Reduces the concentration in the air of gaseous emissions.

Direct vent appliances

Gas appliances that both bring in fresh air and expel flue gases using two pipes

Discharge pipe

A pipe that releases fluids


Used in bath/shower units to divert flow between the tub spout and the showerhead


The vessel in which waste is carried away from the source


A toilet flushing mechanism that determines the amount of water used to flush based on if the material is solid or liquid.


Drain-waste-vent. Allows air to enter and maintain air pressure in a drainage system.

Dynamic pressure

Kinetic energy per unit volume of a liquid.

Effective opening

The smallest cross-sectional area in a pipe or fitting.


The flow of a liquid or gas into a natural body of water, like a sewer pipe.


A fitting used to connect pipes at an angle.


A toilet bowl shape (as opposed to a round bowl).


The area in which a pipe or fixture passes through a wall – an escutcheon plate is typically the divider between the visible finished plumbing and rough plumbing behind the wall.

Essentially nontoxic transfer fluids

Fluids with a Gosselin (toxicity) rating of 1.

Essentially toxic transfer fluids

Fluids with a Gosselin (toxicity) rating of 2.


Flow. Slope of a pipe that will allow for adequate drainage.


A fixture that controls water flow, usually associated with a sink or bath.


Female hose thread.


A color coating on a fixture; brass, chrome, and black are common.


Female iron pipe size.


A small piece used to connect pipes.


An external, finished plumbing part that is connected to a pipe system – like a sink or toilet.


A valve in toilets. Creates a watertight seal in the tank, then raises when the toilet handle is pushed to allow the toilet water to flush out.

Flood level rim

The edge of a plumbing fixture that would overflow if the water inside flooded.

Flush valve

Lives inside the toilet tank. Pushes water into the toilet bowl to allow for flushing.

Flushometer valve

Different than a toilet with gravity flush, this system and valve pressures the water supply system to allow for toilet flush.


Before two pipes are soldered together, flux is used to clean the pipe joints.  


Female national pipe tapered threads.

Friction loss

Loss of pressure, and therefore flow, in a pipe due to the thickness of a fluid.


Gallons per flush. The amount of water necessary to flush a toilet or urinal.


Gallons per minute. Flow rate of water that is usually associated with a showerhead or faucet.

Gas cock

Shut-off valves used with gas appliances.

Gas convenience outlet

Outlets that come with automatic shut-off valves. Provides convenience and safety to anyone using a gas appliance, so they are unable to disconnect the appliance while the gas is still running.

Gravity-fed toilets

The toilet water is flushed with the pressure of gravity.

Gray water

Wastewater that comes from plumbing fixtures; does not contain fecal matter.

Grease trap

Also known as grease interceptor. Is made to catch any grease in water before it reaches the wastewater disposal system.

Hand shower

A showerhead is that is attached to a hose; handheld and movable instead of remaining in place at the top of the shower.


How high a pump can raise water.


A plumber’s aid; usually training to become a plumber.

High efficiency toilet (het)

A toilet that uses less water to flush, in order to conserve energy

High efficiency urinal (heu)

A urinal that uses less water to flush, in order to conserve energy

Hose bib

Water supply valve for connecting hoses; has a threaded male connection.


Hot water.


Inside diameter. Usually referring to pipe measurements.

Indirect waste pipe

Drains waste but, instead of connecting directly to a drainage system, discharges waste to a trap beneath an air gap.

Individual vent

One pipe per fixture for venting.


Iron pipe size. Old pipe sizing method still used by some.


Part that connects two pipes together.


A bathroom sink – basin in the bathroom next to a faucet for washing up.


Old material used for pipes; no longer approved for potable water.

Lead and copper rule (LCR)

Regulation that limits the amount of copper and lead allowed near drinking water.


The regulated amount of lead approved in pipes and fixtures, as determined by the Safe Drinking Water Act.


Low water cutoff. Placed in a boiler to determine an amount of water that is too low.

Male threads

Threads on the outside of a pipe end.


A pipe with sections that are made to distribute water to different outlets, usually in a house.

MaP testing

Grams of solid waste a toilet can flush per single flush.


Measure the amount of water that flows through a water system.


Male hose threads.


A faucet that has handles spread apart by 4 inches.


Male iron pipe.

National pipe thread

U.S. national standards for tapered threads on pipes and pipe fittings.

National primary drinking water regulations (NPDWRS)

Standards for setup and treatment of public water systems.


A small fitting with two male-threaded ends that connect to pipes.

Nonpotable water

Water that is not treated and therefore not safe for drinking.


Nominal pipe size. Standard for pipe sizes.


Outside diameter – a way to measure pipe.


Original equipment manufacturer. A company that produces parts, which another company buys to produce the finished good.


An orifice plate is a thin cover with a hole in it that is placed over a pipe to measure flow rate.


The high and low parts of a pipe – the sections that fall outside the measurement of a circle.

Overflow tube

A tube in the toilet that flows into the bowl to avoid overflowing the tank.


May refer to “Pb” – the chemical symbol for lead. May also refer to Polybutylene plumbing, which is piping made from plastic resin.  


Polyethylene – a thermoplastic material used to make pipes.


Cross-linked polyethylene. Commonly used piping material often compared with copper.


A tube that carries fresh water in or wastewater out of a structure.

Plumber’s putty

Used to seal faucets and drains; a flexible substance that is pressed around the outside of a fixture to form a watertight seal.


A system that transports water both in and out of a building for drinking, cleaning, and heating.


Plumbing manufacturers international. Volunteer organization dedicated to plumbing safety.


Point of connection; the spot where the water is sourced.


A material often used for plumbing fixtures, especially toilets. Made primarily from clay.


Water that has been treated and is safe for drinking.

Pressure balance valve

Provides a consistent temperature to water flow in a shower or bath, balancing water from both hot and cold water supply lines.

Pressure-assisted toilets

The toilet tank has another tank within, which results in additional pressure that allows more water to stay in the toilet bowl and keep it clean.


Fixtures that are in homes or businesses with a private bathroom – intended for use by a small number of individuals and not for commercial use.  

Proposition 65

A requirement in California that states a list of chemicals known to potentially cause harm must be listed – especially applicable in the plumbing industry to plastic piping.

Proximity valves

A valve that allows a fixture to be operated electronically, without being touched.


Pressure regulating (reducing) valve. Keeps water pressure from getting too high.

Pull out spray

A faucet attached to a retractable hose, most often seen in a kitchen sink for washing dishes.


To remove gas from a pipe and replace it with another gas or liquid.


Polyvinyl chloride. Common piping material often compared with copper and PEX.


A type of pipe fitting that reduces the size of the pipe to which it is connected.

Registered design professional

A licensed professional in their respective trade.


Supply line that connects shower faucet to the stop valve.


An in-between stage in installation, after the initial frame is in place but before the final fixtures are installed.

Sanitary fitting

Fittings that are used in settings which require extra sanitation, like food and medical buildings.


Refers to the thickness size of a pipe.


Standard dimension ratio. A pressure rating to determine the durability of a pipe.

Self-closing faucet

A faucet that either expels water for a set amount of time or lets water flow as long as hand motion is detected by a sensor.

Service pipe

The pipe that connects the main water or gas pipe to a structure.


Refers to the system that drains sewage, meaning large amounts of waste, from a building or a city.

Soil pipe

Pipe that carries sewage to a sewer or soil drain.


A way of welding two object together by melting; typically used with attaching fittings to copper pipes.


The end of a fitting that has the same outside diameter as the pipe to which it connects.


The vertical plumbing system for venting or waste in a building one story tall or higher.

Stop cock

A valve that controls the flow of a liquid through a pipe.

Sump pump

Sewage system: wastewater collects in a basin and is then pumped away from the origin.


Pipe between a drain and a trap.


May be referring to a faucet, spigot, or a valve that controls the release of a liquid or gas.


A fitting with a main connection and two outlets; is shaped like a “T.”

Teflon tape

An adhesive tape used for sealing pipe threads.

Tempered water

According to international plumbing code, tempered water is between 85°F (29°C) and 110°F (43°C).

Thermostatic valve

Keeps water temperature regulated by combining hot and cold water.

Top out

All the piping in the walls and roof; all piping above ground in an install.


Threads per inch.

Transfer valve

Allows water to simultaneously flow through multiple outlets.

Transition fittings

Fittings that connect two pipes made from different materials.


A bent pipe that holds water in the bend but allows sewage to pass through. Is designed to prevent sewer gases from entering buildings.

Trip lever

On a toilet, the trip lever is the attached handle and arm in the toilet tank that activate flush.


A fitting that connects two pipes and can be removed without causing any damage.

Universal design

Spaces and products designed to be accessible by all people.

Unstable ground

Ground that is not guaranteed to remain stable, often in reference to pipe placement.


A plumbing fixture like a toilet but for urination only; typically used only by males.


In plumbing, valves regulate the flow of water, whether that means turning it on or off or redirecting it.


A fixture that combines the bathroom sink and storage / cabinets. A vanity is usually a counter space with drawers or cabinets below and a mirror above.

Water efficiency

When a fixture uses the least amount of water necessary to complete its job in order to conserve water.

Water hammer

Hydraulic shock. When the flow of water suddenly stops or changes direction.

Water heater

Heats water for various uses; can be tank or tankless and the method of heating varies.

Water main

The primary pipe in a plumbing system that transports water through a variety of pipes.

Water service pipe

The name for a pipe that comes from the source of drinking building into a building; it is referred to differently once the pipe is inside the building.

Water supply system

The system of pipes that bring water into a structure.


A program created by the Environmental Protection Agency (EPA) that determines and labels water-efficient plumbing fixtures that are made for conservation purposes.

Wax ring

Seals the bottom of the toilet to the toilet flange, which is the piece connected to the floor.

Wet vent

A pipe that serves as both a drain and vent pipe.

Whirlpool bathtub

A bathtub with internal jets that release water; made to be soothing to the user.


A widespread faucet is installed with the two handle holes between six and twelves inches apart.


A fitting shaped like a “Y” that joins pipes at an angle to create a branch system.

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