How must safety and relief valves be installed in relation to the opening on the boiler or pressure vessel?

Safety and relief valves must be installed directly on the opening of the boiler or pressure vessel to ensure proper function and responsiveness. This direct installation allows the valves to effectively manage excess pressure by quickly releasing it when necessary, preventing potential hazards such as explosions or ruptures. A direct connection also minimizes resistance and potential obstruction in the discharge path, allowing for the immediate relief of pressure, which is critical in maintaining safe operating conditions.

Options suggesting indirect installation, flexible connections, or upward angles could introduce delays in pressure relief and could lead to improper operation of the valves. Indirect installations might obstruct the flow, while flexible connections can introduce additional points of failure or vibration issues, and an upward angle may not provide a straight path for discharge, all of which can compromise the effectiveness and safety intended by the installation of safety and relief valves.