What is the difference between a fire sprinkler riser and a wet barrel?

The distinction between a fire sprinkler riser and a wet barrel is based on their specific functions within the fire protection system. A riser is a vertical pipe that carries water from the main supply to various parts of a sprinkler system, effectively distributing water throughout the system when activated by heat or fire detection. This component is crucial in ensuring that water reaches the appropriate sprinkler heads in a timely and efficient manner.

On the other hand, a wet barrel is typically used in systems designed for fire hydrants or external access points and functions to maintain water pressure and flow in the system. This is particularly important for ensuring there is a steady supply of water readily available for immediate use. By having water stored in the barrel, it helps provide a consistent pressure, making it easier for firefighters to use the hydrant without delay.

Thus, the correct answer highlights both roles: the riser is responsible for the distribution of water throughout the sprinkler system, while the wet barrel is focused on maintaining water pressure and flow, ensuring optimal performance when needed.