HVAC Stuff
This colorless, odorless byproduct of incomplete combustion in fuel-burning furnaces is known as the "silent killer."
What is carbon monoxide?
Found inside toilet tanks, this plastic valve regulates the water level by shutting off the flow once the tank refills.
What is a fill valve (or ballcock)
This term describes altering a lock's internal tumbler configuration so that old keys no longer work and new keys do.
What is rekeying
Famous for its intricate clockwork, this famous London landmark's bell weighs over 13 tons and chimed for the first time in 1859.
What is Big Ben
Tradespeople use this slotted hand tool containing liquid in a small vial to check if a surface is perfectly horizontal or vertical.
What is a spirit level (or bubble level)
Modern systems use this synthetic refrigerant blend to replace older R-22 Freon without depleting the ozone layer.
What is R-410A (or Puron)
Installed inside a water heater tank, this metal rod corrodes intentionally to protect the steel tank lining from rust.
What is an anode rod (or sacrificial anode)
Commonly found in high-security lock cylinders, these mushroom- or spool-shaped pins catch under tension to resist lock picking.
What are spool pins (or security pins)
Ancient Romans built these stone architectural wonders to move millions of gallons of fresh spring water into cities purely using gravity.
What are aqueducts
This heavy-duty power saw uses a push-and-pull blade motion to make fast, rough cuts during construction demolition work.
What is a reciprocating saw (or Sawzall)
This electrical component acts like a short-term battery to give an AC compressor or blower motor the initial power surge needed to start up.
What is a run capacitor (or start capacitor)
This flexible, accordion-style plumber's snake features a bulbous tip designed specifically to clear blockages in toilets without scratching the porcelain.
What is a toilet auger (or closet auger)
This type of heavy-duty lock mechanism is encased entirely inside a deep rectangular pocket cut directly into the edge of a door.
What is a mortise lock
Before modern metal keyways, the ancient Egyptians created locks made out of this natural material that utilized wooden drop-pins.
What is wood
The trade classification for craftspeople who build formwork, frame structural walls, and install finish trim on construction sites.
What is carpentry
Measured in inches of water column (in. w.c.), this term refers to the total resistance to airflow throughout a ductwork system.
What is static pressure
Modern homes use this cross-linked polyethylene tubing as an alternative to copper due to its flexibility and resistance to freezing.
What is PEX
This electronic access control system allows a master card or key fob to unlock doors by momentarily cutting power to an electromagnetic holding plate.
What is a magnetic lock (or maglock)
The Hoover Dam was built using so much concrete that engineers had to embed miles of ice-water pipes inside it to prevent the curing heat from cracking the structure.
What is cooling (or heat dissipation)
Electricians use this color-coded wire nut fastener to twist together and insulate stripped copper conductors safely.
What is a wire connector (or wire nut / marrette)
In an air conditioner, this specific state change process occurs when a gas releases heat to become a high-pressure liquid.
What is condensation
The vertical pipe that extends through a home's roof to equalize air pressure in the drainage system and allow sewer gas to escape.
What is a vent stack (or plumbing vent)
Named after the French locksmith who invented it, this mechanism uses sliding key cards with drilled hole patterns instead of traditional mechanical pin tumblers.
What is a VingCard (or hole-card lock)
In 1883, Brooklyn Bridge engineer Washington Roebling directed construction using a light-flashing telegraph after contracting this crippling underwater pressure illness while digging bridge caissons.
What is decompression sickness (or the bends)
This specialized pipe-fitting layout tool projects a centered line around large-diameter steel pipe to guide clean 360-degree bevel cuts.
What is a contour marker (or wrap-around / pipe-centering tool)