What may happen to pipes that are not adequately supported during hydraulic shock?

Pipes that are not adequately supported during hydraulic shock can indeed vibrate or hit against the building structure. Hydraulic shock, often referred to as water hammer, occurs when there is a sudden change in water flow, such as when a valve closes quickly or a pump stops. This abrupt change generates a pressure surge that can create significant forces acting on the piping system.

If pipes are properly supported, these forces can be effectively managed, reducing the risk of damage. However, if pipes are inadequately supported, they lose stability and may vibrate violently or move, leading to physical contact with nearby structures. This can result in noise, wear, damage to the pipes, or even failure at the support points. Adequate support is essential to ensure that pipes can withstand these forces without causing issues in the overall plumbing system.

The other options present scenarios that do not accurately represent the behavior of pipes during hydraulic shock. Pipes do not expand and contract evenly without proper support, and they do not inherently become more resistant to damage in such conditions. Additionally, maintaining the same pressure is not viable during an event of hydraulic shock, as this condition inherently alters pressure dynamics within the system.