What is the purpose of excess air in furnace combustion?
A) Excess air improves the draft efficiency by raising the combustion gas temperature.
B) Excess air ensures that all the gas is burned by making sure there is plenty of oxygen available.
C) Excess air ensures that the heat exchanger does not overheat.
D) Excess air is used for creating a high-fire second stage of combustion.
B
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The accepted rule for determining the angle of a jack arch states that "the skewback angle should be _____ of span of the opening for each 4" of arch depth."
A. ¾' per yard B. ½' per yard C. ¾" per foot D. ½" per foot
An example of a cool season turfgrass is zoysia grass
Indicate whether the statement is true or false
The dot painted on many tires near the major splice indicates ________
A) The smallest diameter of the tire B) A sipe C) The largest diameter of the tire D) None of these
Pressure vessels such as boilers should have a placard on or near the vessel that displays:
A) The material the vessel is made of and the name of the inspector. B) When it was inspected and when the next inspection should be. C) The manufacturing date and type of material the vessel is made of. D) The parts per million casting impurities and the alloy shear strength.