Which of the following represents a lack of support as an abnormal operating condition?

A lack of support in the context of pipe installation refers to issues that may compromise the integrity and safety of the piping system. When pipes are sinking or shifting, it indicates that they are not properly supported, which can lead to stress on the joints and potential failure of the system. Proper support is critical to maintain alignment and prevent undue weight or movement that can result in leaks, breaks, or other hazards.

On the contrary, options that imply stability and care, such as pipes being properly secured, routine inspection, and positive facility feedback, are all indicators of a well-maintained system. Properly secured pipes indicate adequate support, while routine inspections help identify and rectify any issues early on. Positive feedback from facilities suggests that the piping system is functioning as intended without any visible signs of abnormal operating conditions.