The minimum excess pressure for a relief valve in a dry system should be set at what psi?

The minimum excess pressure for a relief valve in a dry system should be set at 5 psi. This pressure setting helps to ensure the system operates efficiently while providing adequate safety measures. In a dry pipe sprinkler system, the pressure must be enough to allow for proper functioning of the system and to prevent false activation.

Setting the relief valve at this specific pressure ensures that the valve will operate as intended under normal conditions, allowing for the necessary pressure buildup. This is important because it can prevent damage to the system from over-pressurization while maintaining the integrity and reliability of the sprinkler system during an emergency. A higher pressure setting might lead to unnecessary stress on the system, while a lower setting could lead to system failure when needed most. Therefore, having the relief valve set at 5 psi strikes an optimal balance in maintaining system performance and safety.