Gas Installation Flashcards
One boiler horsepower is equal to?
33,475 btu
A residential hot water heater has a pressure relief valve pre-set to?
30psig
Make up water to a hot water boiler is installed with a _____________ ___________ _________ to maintain a safe operating pressure on the boiler controls and piping system
Pressure reducing valve
Accessories, controls, and piping for the type of fuel used to fire the boiler are referred to as?
Boiler trim
Materials used in the construction of boilers are?
Cast iron and steel
The term boiler closed vessel
?
Chemical make up of methane
CH4
Heat content of natural gas is generally accepted as?
1000 BTUs
What is added to natural gas as an odorant for safety purposes?
Mercaptan
First gas distribution company was?
In London in 1812
Natural gas and propane are
Non-toxic, tasteless, odorless, colorless, and invisible
Natural gas contains how much methane?
87.4%
Heat sources can be physical chemical or mechanical, combustion is?
Chemical
27.7” WC is how many psi?
1 PSI
Incomplete combustion produces?
Carbon monoxide, water vapor, aldehydes
____________ is required in the combustion air requirements
Excess air
Gas regulators are designed to maintain?
Constant downstream pressure
When heating a thermocouple, a pilot flame is applied to the _____ ____________ to produce thermoelectricity
Hot junction
How many millivolts are produced if a thermocouple is good
30 MV
Electrical control systems may be powered by what voltages
Millivolts, 24v, or line voltage 110
What should be used to pressure test a fuel gas system?
Inert gas or air
Appliance controls, shut off valves, meters, and regulators should not be subjected to?
High pressure testing
Purpose of regulator vent hole
To allow air to escape or enter as the diaphragm moves up and down, also allows gas to vent if diaphragm ruptures
State of Colorado doesn’t allow gas to be run in what material?
Cast iron
Teflon tape is not recommended on steel pipe for gas installation
True
Gas piping on roofs or in corrosive areas must be?
Painted or coated
What must be installed on the outside of buildings incase of emergencies?
Emergency shut off valves
why are compressor stations used on natural gas pipelines
used to recompress gas to maintain constant pressure and to overcome pressure loss created by friction in the pipeline
where when and what length was the first successful natural gas line in North America
Newton Feild to Titusville Pensylvania, 1873, 5 miles long
what is a hydrocarbon
naturally occurring mixture of hydrogen, carbon, and other gasses
name and give the two most commonly used fuel gasses in North America
Methane =CH4 Propane=C3H8
name the odorant in natural gas and propane, and why its used
mercaptan, so the gas is identifiable if present
what is the specific gravity of propane, why is it dangerous
.51, because it is heavier than air so it settles in low places and on the ground where you cant smell it
what do the three sides of the combustion triangle represent
fuel, oxygen, heat, these three components are necessary for combustion to occur
