What are two common methods for controlling pipeline expansion?

The selection of expansion bends and expansion joints as methods for controlling pipeline expansion is appropriate because these devices are specifically designed to accommodate the changes in length that pipelines experience due to thermal expansion.

Expansion bends are strategically installed curves in the pipeline that allow for movement and flexibility, enabling the pipe to bend rather than stress or fracture under the pressures of thermal expansion. This mitigates potential damage to both the pipeline and the surrounding infrastructure, ensuring that the system operates safely.

Expansion joints operate on a similar principle, providing a flexible connection point within the pipeline. These joints can absorb movements caused by thermal expansion and contraction, thereby preventing stress from accumulating in straight sections of pipe. The design of expansion joints often includes materials that can withstand high temperatures and corrosive environments, enhancing their durability and effectiveness in managing the dynamic loads present in piping systems.

The other options provided relate to different aspects of pipeline operation. Pressure valves and temperature sensors are essential for monitoring and maintaining system parameters but do not specifically address the physical changes due to expansion. Control valves and check valves serve different functions of regulating flow and preventing backflow, respectively, without focusing on the changes caused by thermal expansion. Insulation and venting might aid in thermal management but do not directly control the physical movement of pipelines.