Which hydrant type is designed to be drained when not in use to prevent freezing?

Which hydrant type is designed to be drained when not in use to prevent freezing?

• A. Dry Barrel Hydrant
• B. Wet Barrel Hydrant
• C. Hydrant-Lock
• D. Fire Standpipe

Answer: (A)

Dry barrel hydrants are built so the water in the barrel is drained away when the hydrant is shut down, keeping the inside dry. The valve that feeds the hydrant is located underground, and there’s a drain mechanism that lets any remaining water escape back into the main, so the barrel doesn’t hold water. This drainage design is specifically to prevent freezing in cold conditions, which is why it’s the best choice for a hydrant that must be drained when not in use. In contrast, wet barrel hydrants keep water in the barrel at all times, which can freeze in cold weather; hydrant-locks are locking devices, and a standpipe refers to a broader fire protection system rather than a hydrant type.

Dry barrel hydrants are built so the water in the barrel is drained away when the hydrant is shut down, keeping the inside dry. The valve that feeds the hydrant is located underground, and there’s a drain mechanism that lets any remaining water escape back into the main, so the barrel doesn’t hold water. This drainage design is specifically to prevent freezing in cold conditions, which is why it’s the best choice for a hydrant that must be drained when not in use. In contrast, wet barrel hydrants keep water in the barrel at all times, which can freeze in cold weather; hydrant-locks are locking devices, and a standpipe refers to a broader fire protection system rather than a hydrant type.