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on a letter to take you to the list of terms and technical information
starting with that letter.
Therm
100,000 BTU's
Thermal Overload Protector
A device which trips an internal switch to interrupt electrical current to protect against an over current condition.
Thermocouple
A device containing two different metals which produces a small amount of DC voltage when heated. Operates a pilot safety valve.
Thermopile
A group of thermocouples contained in one unit, when heated by a pilot flame millivolts are generated to energize a pilot safety valve or power a millivolt operated control.
Thermostat
An automatic device actuated by temperature changes to control a preset operating temperature.
Transformer
A device for changing one voltage to another voltage.
Tubing Sizes
Type K and L Copper Water Tubing
| Nominal
Size Inches |
Actual Outside
Diameter Inches |
| 1/4 |
3/8 |
| 3/8 |
1/2 |
| 1/2 |
5/8 |
| 3/4 |
7/8 |
| 1 |
1-1/8 |
| 1-1/4 |
1-3/8 |
| 1-1/2 |
1-5/8 |
| 2 |
2-1/8 |
Two-Stage Pilot
A pilot ignition system that uses a small standing pilot flame to light a larger pilot.
Vac
Volts Of Alternating Current
Vacuum
A pressure lower than atmospheric pressure.
VDC
Volts Of Direct Current
Venturi
A piece of pipe that attaches to a burner. Because it narrows down then flares out it Increases gas velocity to create a negative pressure for combustion.
Volt
One volt will produce a flow of one ampere through a one OHM resistance.
| OHM'S LAW |
 |
 |
| VOLTS = AMPERAGE x OHMS |
Voltage
The force of electric current through a circuit.
