What is the purpose of the high limit control on a hot water boiler?
a. To stop the boiler if the water level control fails.
b. To act as a emergency stop for the operator
c. To shut down the burner if the water temperature exceeds 121 deg C.
d. To prevent the pressure in the boiler rising above 210 kPa gage.
e. To prevent excessive pressure from developing
Answer: E
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Power Engineering
- The work done in a constant pressure expansion can be determined by:
- If 10.4 m³ of air is compressed at a constant temperature to 5.1 m³ and 750 kPa gauge. Calculate how much work is done on the gas, assuming atmospheric pressure to be 100 kPa.
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- Find the characteristic constant for a gas if 112 kg of the gas has a volume of 5.7 m³ at 1500 kPa absolute and 27.5°C.
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- If 0.25 m³ of a gas at 4000 kPa gauge pressure is expanded until the gauge pressure is 500 kPa and the expansion is polytropic with n = 1.35. Find the final volume the gas will occupy. Note: Assume atmospheric pressure = 100 kPa
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- The Characteristic Constant of each perfect gas is
- The pressure-volume diagram of a typical air compressor will have a curve drawn:
- If 10.4 m³ of air is compressed at a constant temperature to 5.1 m³ and 750 kPa gauge. Calculate how much work is done on the gas, assuming atmospheric pressure to be 100 kPa.
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- The formula Work = (P1V1 - P2V2) / n - 1 is used to describe expansion during:
- To "expand a gas" means the gas is:
- The work done in a constant pressure expansion can be determined by:
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- The General Gas Law can be written using the formula/s:
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