Final answer:
Cross connections are preferred over elbows on water column connections mainly because they allow for easier cleaning and may provide more strength to the system. The design facilitates better access for maintenance and distributes stress more evenly, potentially reducing joint failures. Option c) line may be easily cleaned is the correct answer.
Step-by-step explanation:
In the field of engineering, specifically when dealing with plumbing and fluid systems, cross-connections are often used instead of elbows on water column connections for several reasons. One of the main reasons is that cross connections provide a means for easier cleaning and maintenance of the line. Unlike elbows, which can create difficult corners and areas where sediment can accumulate, cross connections allow for direct access at intersections, making it simpler to disassemble and clean parts of the system as necessary. Although the cost might initially seem a factor, and cross-connections may offer some cost benefits through reduced maintenance costs, the primary benefit is usually operational rather than financial.
Furthermore, cross-connections can sometimes offer more strength to a plumbing system. The intersecting lines of a cross-connection distribute stress more evenly across the connection, especially in high-pressure systems, potentially reducing the risk of failure at joint points. This is particularly important in industrial applications where the integrity of the water column is critical. The structure and additional connection points inherent in the design of a cross can contribute to a more robust and reliable plumbing system.
Finally, incorporating cross connections over elbows does not necessarily mean that the cross connection will be less expensive (cost less as stated in the initial question may not always be accurate). The choice between using a cross or elbow can be dependent on the overall design specifications, maintenance requirements, and operational needs of the system rather than cost alone.