Final answer:
Dry pipe valves are usually set at 10 psi above the normal trip level to provide a safety margin and prevent false activations in fire sprinkler systems.
Step-by-step explanation:
DRY PIPE VALVES ARE USUALLY SET AT 10 psi ABOVE THE NORMAL TRIP LEVEL.
The normal trip level refers to the pressure at which the dry pipe valve opens to allow water flow in the event of a fire. By setting the valve above the normal trip level, a safety margin is established to prevent false activation. For example, if the normal trip level is set at 50 psi, the dry pipe valve will be set to open at 60 psi.
This additional pressure requirement helps to ensure that the system is not activated due to small leaks or minor spikes in pressure, providing a more reliable and accurate response to fire incidents.