What Do You Know About Home Plumbing?



By: Zoe Samuel

7 Min Quiz

Image: Michael Blann / DigitalVision / Getty Images

About This Quiz

Plumbing takes its name from the Latin word for lead: plumbum. Back in the days of ancient Rome, pipes were usually made of lead, which, while it caused plenty of health problems, solved more than it created. Plumbing made Rome a modern city, and helped stop plagues for centuries. Today, much of the ancient Roman sewers are still functioning, and in fact, still in use. The Romans even lined in marble the section of the sewer that passed under the emperor's palace.

Throughout history, plumbing has been the dividing line between modern civilization and barbarism. London was more or less a medieval city until sewers firmly planted it at the heart of everything modern, in the industrial revolution. Paris's sewers radically reduced the spread of disease and the smells that Paris was previously known for. Visit any modern city when there is a sewer malfunction and you will see the degree to which an open sewer changed urban life.

Things aren't much different at home. Compare the convenience of a toilet or a shower with that of a chamber pot or pouring buckets of water over one's head. Anyone who has had a major plumbing problem knows how inconvenient it is to lose access to these modern marvels. Furthermore, today, plumbing covers how highly flammable gas is transported, and plumbers not only risk a mess if they make a mistake, they could get someone killed.

All this in mind, how much do you really think you know about home plumbing?

What is a pipe wrench used for?

Pipe wrenches are the big, heavy tools used by plumbers to hold and turn pipes. They consist of serrated jaws attached to long metal handles that work as a lever.


What's the best place to look for evidence of leaky pipes?

The basement is almost always the best place to look for evidence of a leak. Basements will usually show the leak in the form of buckled ceilings, droplets of water coming from the ceiling, puddles on the floor or mold.


What is a Roman tub filler?

The Romans invented many things which we still use today: highways, aqueducts, artificial breakwaters, but this simple tap design is one of their most enduring inventions. Simply put, it is two pipes, one containing hot water, one cold water, leading to two taps, and then from the taps to a single spout. By adjusting the taps, you can let in just enough water to make you feel warm.


What should the water pressure in the average house be?

Water pressure is an important detail in plumbing. This should be obvious. If pipes aren't sufficiently sturdy, too much pressure will cause them to break and leak. The average water pressure a house should have is 80 psi or less. Going over that will damage most household plumbing and plumbing fixtures.


What might an apartment building install in order to monitor individual units' gas consumption?

In urban architecture, it can be a challenge to measure how much to bill each tenant in an apartment complex for their use of gas for cooking and heating. One way to take care of the former is to use a submeter, which measures the gas usage by that single unit.


Which of these is not a real kind of trap?

Traps, which pevent everything from clogs to gas entry into the home to pests entering sewers, come in many varieties. P and S traps (so named because of their shapes) connect to fixtures in the house, whereas gully traps prevent sewer gases from entering the home. Since Apple hasn't gotten into the plumbing business, there is no i-trap ... yet.


What does a dishwasher air gap stop from happening?

A dishwasher air gap is a device attached to the pipe coming out of the dishwasher. The wastewater pipe from the dishwasher goes up, sometimes to the level of the kitchen sink (in which case this device may be part of the sink hardware, in the form of a bump) where it attaches to one end of the air gap device, and then another pipe comes down from the air gap to the wastewater pipe for the kitchen.


Which of the following is not a mechanical joint?

Mechanical joints are pipes or fittings that produce a watertight seal. This can be done with couplings, gaskets, bolts, nuts, nipples, etc. Think of it as a category, not a thing unto itself.


Which of the following is a potential health hazard?

A cross connection is when you have potable water pipes connected to non-potable water pipes. An example would be when someone connects a hose with chemicals to a sink without a vacuum breaker.


How old is the manhole?

The oldest manholes (covers for covered trenches filled with sewage, mostly made of wood or stone slabs) have been dated to as far back as 3500 BC. The modern manhole cover as we think of it was a product of the industrial revolution, in the 1800s. Many of the manhole covers used today are manufactured in India.


What kind of sewer is disappearing from the American landscape?

Combination sewers were a great, cost-effective idea once, but back then the alternative was having no sewer at all. Today, we know well that when there is a flood, the sewers that collect storm water will overflow. This is bad when that sewer is a combination sewer, because that means all the wastewater from all the toilets connected to that sewer will also spill forth when the sewers overflow into the streets. Gross.


What is the main difference between a loop vent in a home and a loop vent in a commercial building?

The loop vent is essentially a pipe that rises up from a line linking a sink to a sewer, allowing gases coming up from the sewer pipe to bypass the sink and exit through the end of the pipe, in the roof of the building. In a home, it would usually be attached to a kitchen sink (or if on a kitchen island it would be called an "island vent") but in an industrial or commercial space, it might connect to several unvented lines, giving them all a single vent.


What do some municipalities require of every coffee station?

The buildup of saturated fats in what sewer workers have dubbed "fatbergs" is extremely dangerous. Chemical changes can make fatbergs an explosive danger, so it is suggested that people do not pour grease down the sink. Interestingly, some municipalities have taken this a step further, requiring a special grease interceptor be installed in sinks, so the grease does not go into the wastewater pipes.


Which of these is a plumber likely to use in this day and age?

Lead picks are used to remove lead where it is poured onto joints, etc. Lead isn't used much anymore, and in most places, not at all. Lead, if it gets into the water supply, is dangerous. These days, plumbers are more likely to remove lead and replace it with something else, rather than put lead into a plumbing setup.


What do you call those U-shaped things that hang pipes from the ceiling?

If you look up at a construction site and see exposed pipes hanging from the ceiling, they are probably suspended with U-shaped pieces of metal bolted to the ceiling. These devices are called Clevis hangers, and are designed to hold pipes in place while allowing just enough play to accommodate the expansion and vibration of the pipes, and in certain areas where building codes require more specific varieties of hangers, earthquakes.


What should you make sure to do with your outside water pipes in winter?

In winter, outdoor pipes water pipes freeze and break. To make sure this does not happen to you: first, if no one is home, you should turn off the water and leave the water valve open so the pipe empties out. This way the water won't freeze, expand and break the pipes. Second, if you plan to be around, wrap the pipe in some form of insulation to keep it from freezing, otherwise you'll be in big trouble.


What do you call a valve designed to allow water to enter in one direction, exiting through one exit, allowing the system to shut the valve if there is a sudden change of pressure?

Check valves are important plumbing apparatus because they are relatively small, and do an important job. They allow liquid to pass through in one direction, and many check valves are automatic, meaning they can slam shut if the liquid changes pressure or direction. There is even a very thin check valve type called a wafer check valve, that can be used either to save weight or to save space.


Which of these people is most likely to need a bleed valve?

Bleed valves are the valves on radiators set to automatically release, or "bleed" steam when the radiator has too much steam inside it. It's what you hear when a radiator suddenly starts hissing. If you're in a house that is too cold, you'll need a radiator that's working, and that means a good bleed valve.


What causes the sound of knocking coming from your radiator?

Water hammer, as it is called in plumbing, is a pressure surge resulting from a fluid being forced to change direction or speed. Originally discovered as a force in human physiology, it had been noticed by scientists going back to antiquity, and is the basis for several inventions that use hydraulic power. A water hammer arrestor is a device used to reduce water hammer in plumbing.


What would you call a boiler that takes care of heating and boiling water for use in the taps?

A combi boiler is a boiler that does two jobs. On one hand, it boils water for showers, taps, etc. On the other hand, it heats the building. Combi boilers are usually huge affairs, especially in larger structures where the job is being done for hundreds of units.


What's a fancy name for the black plastic pipe used in plumbing?

The black plastic plumbing pipe you may have seen peeking out of a wall or ceiling is made of a kind of plastic called ABS plastic or "acrylonitrile-butadiene-styrene". As it turns out, ABS is the same tough plastic used to make a lot of children's toys, and other plastic objects with the need for extreme toughness.


How might you know if your water heater is dead?

If your water heater is surrounded by puddles, that is a bad sign. You might be able to get it fixed, but if it is leaking, and that leak is constant and ongoing, then replacing it is sometimes cheaper than fixing it.


How long will a washer last, in a plumbing context?

Washers may be "hard" ware, but they don't last as long as the name would suggest. Washers tend to give out after about 3 years, with deterioration setting in at about 2 years. When you install an appliance that uses washers, buy several extra and keep them with a card indicating when you should replace the old ones, and how.


Which of these is an acceptable use of a heat exchange unit?

A heat exchange unit is a component that, taken on its own, could be used for heating or for cooling a fluid. In most cases you might experience, it will be used as part of a boiler, to heat water. However, technically the heat can be "exchanged" in either direction.


When you suspect a leak, what should you do to your radiators?

A leaky radiator can be fixed by pushing the valve so it points back into the steam pipe. By doing this, when water collects (via condensation) it will roll back into the steam pipe and down to the boiler. This doesn't always work, but it's a good first step.


What might you call the thing in your toilet's tank with a floating sphere on the end?

The ball cock in your toilet tank is a type of valve called a float-operated valve. It uses a float (the rubber ball) to control what is in essence, a switch. When the ball is high (due to high water level) the valve is shut and the tank does not allow in fresh water from the mains. When the water level goes down (you flush the toilet) the ball goes down and the tank opens the valve, allowing fresh water to fill the tank again.


What is the main advantage of a tankless water heater?

Tankless water heaters are a new innovation that heats water on demand. Some of the advantages of these devices include no standby heat loss (there's no giant tank of constantly heated water just sitting there), therefore you spend less to heat the water, which in turn uses less fuel, which is "greener".


What does warm air wafting out from under the sink probably mean?

Warm air under the sink is often a sign that there is warm water leaking from somewhere. This could be due to a clog, or something else. Either way, it needs addressing, and this is certainly a case of "a stitch in time saves nine"!


What is the difference between sewage and wastewater?

Sewage actually refers to the "solid" (or semi-solid) waste found in sewers. Wastewater contains the elements of sewage, but isn't sewage. Sewage has things in common with wastewater but isn't wastewater. Rule of thumb: If it's in a sewer, it's sewage.


What are J-hooks used for?

J hooks are a kind of hardware fixture used to hang pipe. They can be made of plastic or metal, are shaped like their letter namesake, and are usually screwed into wooden joists to hold up water piping or vents.


What is a plumbing manifold?

A plumbing manifold is a fitting connecting many lines together. For example, it could connect the branch on one floor of a stack to many bathrooms, etc. The term manifold has many uses outside plumbing, of course; one might even say they are manifold!


What must never be put into a septic system if that septic system drains into a septic tank?

It sounds counter-intuitive to include drain cleaner in this list, but like all of these chemicals, one should never put it in a septic tank. Septic tanks are full of biological activity, producing a variety of chemicals which, combined with the right solvents, bleaches or drain cleaners, can produce toxic or even explosive gases.


What is gray water?

Wastewater from sinks, tubs and showers is different from that coming from toilets. This is pretty obvious, so there is a special term for this waste water: gray water. It's not soiled in the same way as waste water from toilets, so it gets a special name.


What is a power rodder?

The unfortunately named power rodder is a snake or auger that is powered by electricity. Traditional rodders are powered by a hand crank, which can take ages to use, but has certain advantages some plumbers prefer, like feeling resistance. Power rodders can get the job done faster, because instead of hand crank, it basically has a power drill.


Who was responsible for the design and building of London's sewer system, which became the basis for sewers the world over?

Sir Joseph William Bazalgette was the brilliant engineer behind the transformation of London's soiled waterways, most already filled with sewage, into bricked-in, covered transportation for the ills of the indoor outhouse. His brilliant design, still in use today with remarkably little in the way of change, meant that London's rates of disease dropped.


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