What type of device should pressure vessels be equipped with according to installation instructions?

Pressure vessels must be equipped with a pressure relief valve according to installation instructions due to its essential role in maintaining safety and preventing overpressure conditions. A pressure relief valve is designed to automatically open when the pressure inside the vessel exceeds a predetermined limit, allowing excess pressure to escape and thus protecting the equipment and surrounding environment from potential damage or catastrophic failure.

The pressure relief valve is specifically engineered to handle variations in pressure and ensure a consistent operational level. It can respond rapidly to fluctuations, making it vital for maintaining the integrity of the system. This precaution is critical in various applications, especially in industrial and commercial settings where pressure vessels are often subjected to high pressures and temperatures.

Other devices listed, such as safety valves, overflow valves, and expansion tanks, serve different purposes. While a safety valve also functions to protect against overpressure, the term is often used in specific contexts or applications distinct from pressure relief valves. Overflow valves are designed to manage excess liquid in a system, and expansion tanks are used to absorb pressure changes due to thermal expansion in closed systems. Therefore, the correct focus for protecting pressure vessels is through the use of pressure relief valves as specified in installation instructions.