Flexible lines must be installed with what percentage of slack based on their length?

• A. 2 to 4 percent
• B. 5 to 8 percent
• C. 10 to 12 percent
• D. 1 to 3 percent

Answer: (B)

Flexible lines must be installed with a percentage of slack that typically ranges from 5 to 8 percent of their length. This slack is essential to accommodate the natural movement and expansion of the lines during operation, which can result from fluid dynamics, temperature changes, and system vibrations. By incorporating this range of slack, flexibility is maintained while also preventing undue stress on the fittings and connections. If the lines are too tight, they could become damaged over time, leading to leaks or failures in the system. Thus, the specification of 5 to 8 percent slack is designed to ensure reliability and longevity of the flexible lines in various applications.