Above what operating pressure threshold is a boiler classified as a high-pressure unit_________________?
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Answer: E. 75-80 kg/cm2
Explanation
Boilers operating at pressures above 75 to 80 kg/cm2 are generally classified as high-pressure units. Generating steam at these elevated pressure thresholds requires specialized thick-walled alloy steel tubing and forced circulation. High-pressure classification distinguishes utility power station boilers from low-pressure industrial heating boilers. Industrial boilers are categorized into low, medium, and high-pressure classes based on their maximum allowable working pressure. Operating above 75 kg/cm2 significantly increases the saturation temperature and thermodynamic cycle efficiency. High-pressure boilers require advanced water treatment systems to prevent scale deposition and tube overheating failures.
Electric power generation plants utilize high-pressure boilers to drive multi-stage steam turbines efficiently. Engineers enforce strict safety codes, regular ultrasonic testing, and pressure relief valve maintenance for high-pressure units. Exceeding pressure design limits without proper safeguards can lead to catastrophic steam explosion accidents. Atmospheric pressure represents unpressurized open systems rather than industrial high-pressure boiler operating thresholds. A pressure of 5 kg/cm2 characterizes low-pressure heating boilers rather than high-pressure power generation equipment. A pressure of 10 or 40 kg/cm2 falls into low or medium-pressure classifications rather than the high-pressure category.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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