What is the maximum variation in pressure and temperature that is permissible for no more than 80 hours per year?

The correct answer, which specifies a maximum variation of 20% in pressure and temperature permissible for no more than 80 hours per year, is rooted in safety and operational guidelines for high-pressure piping systems.

This 20% variation threshold is typically established based on industry standards and practices, which balance the need for flexibility in operational conditions with the importance of maintaining system integrity and safety. Exceeding this variation could compromise equipment performance, increase the risk of failure, and potentially result in hazardous situations. Therefore, having a well-defined limit allows operators to effectively manage their systems within acceptable safety margins while still accommodating unusual operational needs or temporary conditions.

Lower thresholds, such as 10% or 15%, might restrict operations too tightly, making it difficult to adapt to fluctuating demands or unexpected scenarios, while a 25% variation is generally deemed excessive and may increase the risk of safety incidents. Adhering to the established 20% variation aligns with best practices in the industry, ensuring both operational efficiency and safety.