An approved relief valve on a dry system must relieve pressure at least how many psi above the system air pressure?

The correct answer states that an approved relief valve on a dry system must relieve pressure at least 10 psi above the system air pressure. This requirement is essential for ensuring the safety and integrity of the dry pipe sprinkler system.

In a dry pipe system, the air pressure within the pipes keeps the water from flowing into the system until the sprinklers activate. If the pressure within the system were to exceed safe limits, the relief valve plays a critical role in preventing potential damage, such as pipe bursts or valve failures. By requiring the relief valve to open at least 10 psi above the system air pressure, it allows a buffer that helps accommodate normal fluctuations in pressure and ensures that the system operates safely during its intended use.

Choosing a lower threshold, such as 5 psi, would not provide adequate protection, as it might open too early due to minor fluctuations in pressure. Options suggesting a higher threshold, such as 15 psi or 20 psi, could be unnecessarily restrictive, potentially limiting the performance of the system when it needs to function effectively. Ensuring that the valve relieves at least 10 psi above the system pressure strikes a balance between safety and operational efficiency.