Question 1

Absolute pressure

Accepted Answer

Pressure measured relative to a perfect vacuum (zero pressure).

Question 2

Air-fuel ratio

Accepted Answer

The mass ratio of air to fuel in a combustion process.

Question 3

Altimeter setting

Accepted Answer

Pressure adjusted to sea level used for altitude measurements.

Question 4

Anode

Accepted Answer

A sacrificial metal that corrodes to protect another metal from corrosion.

Question 5

Atmospheric pressure

Accepted Answer

The pressure exerted by the weight of the atmosphere at any given point.

Question 6

Back pressure

Accepted Answer

The pressure created by a flow restriction downstream of a valve or device.

Question 7

BTU (British Thermal Unit)

Accepted Answer

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

Question 8

Burner capacity

Accepted Answer

The maximum heat output of a burner under specified conditions.

Question 9

Carbon monoxide (CO)

Accepted Answer

A colorless, odorless, and toxic gas produced from incomplete combustion.

Question 10

Combustion chamber

Accepted Answer

The enclosed space where fuel is burned in a heating system.

Question 11

Condensate

Accepted Answer

The liquid formed by the cooling and condensation of water vapor in a gas stream.

Question 12

Corrosion inhibitor

Accepted Answer

A chemical added to a fluid to reduce or prevent corrosion of metal surfaces.

Question 13

Dead leg

Accepted Answer

A section of piping with no flow that may trap contaminants or cause corrosion.

Question 14

Dew point

Accepted Answer

The temperature at which water vapor in a gas stream begins to condense into liquid.

Question 15

Draft

Accepted Answer

The flow of combustion gases through a combustion chamber and venting system.

Question 16

Drip leg

Accepted Answer

A short section of pipe installed to collect and remove condensate from a gas line.

Question 17

Electronic ignition

Accepted Answer

A system that uses an electric spark to ignite a gas/air mixture in a combustion chamber.

Question 18

Expansion tank

Accepted Answer

A tank used to absorb excess pressure caused by thermal expansion in a closed system.

Question 19

Flame safeguard

Accepted Answer

A device that monitors the presence of a flame and shuts off the fuel supply if the flame is lost.

Question 20

Flue gas analysis

Accepted Answer

The measurement and analysis of the composition and properties of combustion gases.

Question 21

Gas appliance pressure regulator

Accepted Answer

A device that maintains a constant gas pressure to an appliance.

Question 22

Gas cock

Accepted Answer

A valve used to control the flow of gas to an appliance or system.

Question 23

Gas pressure test

Accepted Answer

A test to verify that a gas system is free of leaks and can maintain a specified pressure.

Question 24

Heat exchanger

Accepted Answer

A device that transfers heat between two fluids without mixing them.

Question 25

Heat input

Accepted Answer

The amount of heat added to a system, typically measured in BTUs per hour.

Question 26

High-limit control

Accepted Answer

A safety device that shuts off a heating system if the temperature exceeds a set point.

Question 27

Hydronic system

Accepted Answer

A heating or cooling system that uses water or another fluid as a heat transfer medium.

Question 28

Infrared heater

Accepted Answer

A heater that uses infrared radiation to transfer heat directly to objects or people.

Question 29

Lockout

Accepted Answer

A safety feature that prevents a system from operating if certain conditions are not met.

Question 30

Low water cutoff

Accepted Answer

A safety device that shuts off a boiler if the water level drops below a safe level.

Question 31

Manifold pressure

Accepted Answer

The gas pressure in the manifold of a gas burner or appliance.

Question 32

Manometer

Accepted Answer

An instrument used to measure pressure differences in gases.

Question 33

Maximum allowable working pressure (MAWP)

Accepted Answer

The maximum pressure that a vessel or system is designed to safely withstand.

Question 34

Natural draft

Accepted Answer

The flow of combustion gases through a venting system due to the difference in density between the gases and the surrounding air.

Question 35

Orifice

Accepted Answer

A small opening through which gas flows to control its flow rate and pressure.

Question 36

Overpressure protection

Accepted Answer

A device or system designed to prevent pressure in a system from exceeding a specified limit

Question 37

Pilot light

Accepted Answer

A small, continuously burning flame used to ignite the main burner in a gas appliance.

Question 38

Pressure drop

Accepted Answer

The decrease in pressure as a fluid flows through a pipe or other component.

Question 39

Pressure relief valve

Accepted Answer

A safety valve that opens to release excess pressure in a system.

Question 40

Primary air

Accepted Answer

The air supplied directly to the burner for mixing with the fuel gas.

Question 41

Purge

Accepted Answer

The process of removing air, gas, or other contaminants from a system before use.

Question 42

Radiant heating

Accepted Answer

A method of heating that transfers heat directly from a warm surface to objects and people in a space.

Question 43

Rated input

Accepted Answer

The maximum fuel consumption of an appliance under specified conditions.

Question 44

Regulator vent

Accepted Answer

An opening on a gas pressure regulator that allows it to sense atmospheric pressure.

Question 45

Secondary air

Accepted Answer

The air supplied to a combustion chamber after the primary air to support combustion.

Question 46

Spud

Accepted Answer

A threaded fitting used to attach an orifice to a burner or valve.

Question 47

Stack temperature

Accepted Answer

The temperature of combustion gases as they exit the flue or venting system.

Question 48

Standing pilot

Accepted Answer

A continuously burning pilot light that remains lit even when the main burner is off.

Question 49

Thermocouple

Accepted Answer

A device that generates a small voltage when heated, used to sense temperature or control gas valves.

Question 50

Thermopile

Accepted Answer

A series of thermocouples connected in series to generate a larger voltage for control or measurement purposes.

Question 51

Vent connector

Accepted Answer

The pipe that connects a gas appliance to a chimney or vent.

Question 52

Vent damper

Accepted Answer

A device that controls the flow of combustion gases through a venting system.

Question 53

Venting system

Accepted Answer

The assembly of pipes and components used to exhaust combustion gases to the outdoors.

Question 54

Viscosity

Accepted Answer

A measure of a fluid's resistance to flow.

Question 55

Water column

Accepted Answer

A unit of pressure equal to the pressure exerted by a column of water 1 inch high at a temperature of 39.2°F.

Question 56

Zone valve

Accepted Answer

A valve used to control the flow of fluid in a hydronic heating system to individual zones or rooms.

Question 57

Zone control system

Accepted Answer

A system that divides a building into separate heating or cooling zones, allowing for independent temperature control in each area.

Question 58

Gas detector

Accepted Answer

A device that detects the presence of gas, typically used to alert occupants to a gas leak or other hazardous conditions.

Question 59

Gas meter

Accepted Answer

A device that measures the volume of gas consumed by a building or appliance.

Question 60

Leak detection solution

Accepted Answer

A liquid applied to gas connections to identify leaks by producing bubbles.

Question 61

Pipe dope

Accepted Answer

A sealant applied to the threads of pipe fittings to prevent leaks and facilitate assembly.

Question 62

Pressure reducing valve

Accepted Answer

A valve that reduces the pressure of a fluid to a lower, specified value.

Question 63

Gas train

Accepted Answer

A series of components used to control and regulate the flow of gas to a burner or appliance.

Question 64

Cross-connection

Accepted Answer

An undesirable connection between a potable water system and a non-potable source, which could cause contamination.

Red Seal Exam Gasfitter - Class A Flashcards