What is the minimum size of a common drain for sprinkler systems with floor control valves that have 1 1/2" drains?

The minimum size of a common drain for sprinkler systems with floor control valves that have 1 1/2" drains must be adequately sized to handle the flow of water without causing backpressure or potential issues such as clogs. A 2" diameter drain is often specified in codes and standards as the appropriate size to accommodate the drainage requirements of systems with 1 1/2" drains. This size ensures that the water can flow freely and quickly from the system without hindrance, maintaining the integrity and performance of the fire protection system. A larger drain allows for greater water volume, which can be crucial during scenarios where rapid drainage is necessary, such as in the event of a system activation. Proper sizing of drains is essential to maintain effective drainage and to ensure compliance with regulatory standards for sprinkler systems.