What issue might arise with butterfly valves during operation?

The issue that can arise with butterfly valves during operation pertains to improper seating. Butterfly valves are designed with a rotating disc that either allows or restricts the flow of a fluid. If the valve is not properly seated, it may not close completely, leading to leaks or inefficiencies within the system. This improper seating can result from factors such as wear and tear, dirt and debris obstructing the sealing surfaces, or misalignment during installation. Ensuring a proper seal is critical in maintaining system integrity, especially in applications involving the transfer of liquids, where leaks can lead to significant operational and safety concerns. Proper maintenance and regular inspections are essential to mitigate this issue and ensure the reliability of butterfly valves in various systems.

The other options do not accurately reflect operational challenges associated with butterfly valves. For example, although automation is easier with these valves, that does not pose an operational issue. Durability compared to gate valves may vary based on specific models and applications but is not a general concern for their operation. Lastly, while manufacturing costs may vary, expense does not directly impact the operational integrity or performance of butterfly valves in the field.