What is the primary purpose of the check valve in a fire department connection?

The primary purpose of a check valve in a fire department connection is to prevent water from a sprinkler system from flowing back into the supply line. This is crucial for maintaining the integrity and functionality of the water supply system. The check valve allows water to flow in one direction—toward the fire and into the system—while preventing any reverse flow. This is particularly important during firefighting operations where multiple sources of water might be connected, ensuring that the sprinkler systems only release water when needed and do not contaminate the municipal water supply or cause issues with pressure regulation.

Maintaining the direction of flow helps protect the infrastructure and ensures that the fire department can effectively manage firefighting efforts without risking backflow, which can compromise water quality and pressure in the system used to fight fires.