In what position must steam safety and pressure relief valves on boilers be installed?

The requirement for steam safety and pressure relief valves to be installed in an upright vertical position is crucial for their proper operation. When these valves are installed vertically, it ensures that the mechanism operates effectively by allowing the steam and pressure to exert force directly on the valve's disk. This configuration minimizes the risk of obstructions and contaminants that could affect the valve's functionality.

Moreover, the vertical installation helps facilitate proper drainage of condensate that may accumulate within the valve body. If the valve were to be installed at an angle or in a horizontal position, there could be an increased risk of trapped vapor or liquid, which can cause operational issues or even valve failure.

This guideline aligns with safety standards and manufacturer recommendations that prioritize the reliability and efficiency of pressure relief systems in their intended applications. Therefore, the upright vertical position is not just a preferred method; it is often mandated to ensure the safety and proper functioning of steam systems.