How does the set pressure of a boiler drum safety valve compare to that of the superheater safety valve________________?
Show answer Hide answer
Answer: B. higher value
Explanation
Boiler drum safety valves must be set to a higher pressure than superheater safety valves. This ensures the superheater safety valve opens first during an overpressure event. Opening the superheater valve first maintains continuous steam flow through the superheater tubes. Superheater tubes require continuous steam cooling to prevent overheating and metal failure. Allowing drum safety valves to vent first would starve the superheater of cooling steam. Proper valve pressure staggering protects critical high-temperature boiler components.
Power plant safety protocols require rigorous testing of all boiler drum and superheater valves. Operating high-pressure boilers safely depends on correct safety valve pressure hierarchies. Superheater tube failure from overheating can cause catastrophic forced plant outages. Equal pressure settings would risk starving the superheater of essential cooling steam. Lower boiler drum safety valve settings would bypass the superheater protection mechanism. Unpredictable settings violate mandatory boiler code safety requirements entirely.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. What underlying factors are primarily responsible for the development of waiting lines or queues ___________________?
Show answer Hide answer
Answer: D. all of the above
Queues develop when arrival rates exceed service rates, causing customers to accumulate over time. Fluctuating input combined with constant or random output rates naturally creates temporary system backlogs. All listed o...
Q2. Under what condition will the normal stress at a point in a fluid remain uniform in all directions__________________________?
Show answer Hide answer
Answer: E. it is at rest
When a fluid is at rest, shear stresses are zero, meaning the normal stress is isotropic and uniform in all directions. Stationary fluid molecules do not experience relative sliding motion, eliminating directional fricti...
Q3. How do tube diameters in natural circulation boilers compare to those in controlled circulation units___________________?
Show answer Hide answer
Answer: A. more
Natural circulation relies entirely on density differences between heated and cooled fluid columns. Larger diameter tubes provide reduced flow resistance to maintain adequate thermosiphon circulation rates. Forced circul...
Q4. What are the standard shell dimensions (diameter and length) of a locomotive boiler_______________?
Show answer Hide answer
Answer: A. 1.5 m, 4 m
A standard locomotive boiler typically features a cylindrical shell with a diameter of about 1.5 meters and a length of 4 meters. These compact dimensions fit within the strict clearance gauge limits imposed by railway t...
Q5. In what direction does the resultant of all normal pressure forces act___________________?
Show answer Hide answer
Answer: C. vertically upwards
Archimedes principle dictates that buoyant forces equal the displaced fluid weight acting upwards. The resultant normal pressure forces integrate to a single net upward force vector. This net vertical force acts directly...
Q6. In a petrol engine, specific fuel consumption drops initially and then rises with an increasing air-fuel ratio; within what range does the minimum occur__________________?
Show answer Hide answer
Answer: A. lean mixture
Specific fuel consumption measures the mass of fuel consumed per unit of power output produced by an internal combustion engine. As the air-fuel ratio increases from rich toward lean, combustion becomes more complete and...