Final answer:
The number of sheets required for piping routing depends on the plant design and the volume of chemicals processed. Understanding economies of scale, as illustrated by the six-tenths rule, helps engineers balance cost and efficiency.
Step-by-step explanation:
The number of sheets required for large or complex piping routing can vary significantly based on the specific requirements of the chemical process and the plant design. When talking about the sizing and cost-effectiveness of pipes in the chemical industry, it's important to understand the concept of economies of scale. Chemical plants often use pipes ranging from 4-inch pipe to 16-inch pipe and beyond, depending on the volume of chemicals that need to be processed.
For instance, Table 7.15 Comparing Pipes suggests that a 4-inch pipe that uses twice as much material to make may carry up to four times the volume of chemicals because the cross-section area of the pipe increases by a factor of four. This is a reflection of the so-called "six-tenths rule," where increasing the quantity produced by a certain percentage in a chemical plant will only increase total costs by six-tenths as much. Therefore, when determining the number of sheets for piping layout, chemical engineers must balance the cost and efficiency to take advantage of economies of scale.