Which item is crucial for ensuring the stability of pipe joints in water distribution systems?

Thrust blocks are essential in water distribution systems for maintaining the stability of pipe joints. When water flows through pipes, particularly at points of change in direction, pressure fluctuations can occur. These fluctuations may lead to movement or separation at joints, which can result in leaks or even pipeline failure.

Thrust blocks are designed to counteract these forces by providing a solid foundation that supports the pipe at the joints. They are typically placed against fittings, such as elbows and tees, to absorb the thrust generated when water moves through the system. The weight and design of the thrust blocks ensure that the pressure forces do not displace the pipe joints, thus protecting the integrity of the water distribution system.

In contrast, while mechanical seals, expansion joints, and detention tanks play roles in the overall function of water systems, they do not specifically address the stability of pipe joints with the same effectiveness that thrust blocks do. Mechanical seals are used to create watertight connections, expansion joints accommodate thermal expansion or contraction, and detention tanks manage water storage and flow but do not provide direct support to prevent joint displacement.