Which type of venting applies only to floor drains which depend on siphonage for proper operation?

Which type of venting applies only to floor drains which depend on siphonage for proper operation?

• A. Loop Vent
• B. Common Vent
• C. Dry Vent
• D. Relief Vent

Answer: (A)

Loop vent is the venting method designed for floor drains that rely on siphonage. It works by routing a short section of vent pipe up from the floor drain and looping it back down to connect near the trap, allowing air to enter the drain line as water flows. This prevents the trap from being siphoned and maintains the water seal, which is essential for floor drains that don’t have a traditional vent connection nearby. Other vent types serve different situations: a common vent handles multiple fixtures sharing one vent, a dry vent is used in configurations where the vent must stay dry above a horizontal run, and a relief vent provides an extra vent to protect traps in longer fixture runs.

Loop vent is the venting method designed for floor drains that rely on siphonage. It works by routing a short section of vent pipe up from the floor drain and looping it back down to connect near the trap, allowing air to enter the drain line as water flows. This prevents the trap from being siphoned and maintains the water seal, which is essential for floor drains that don’t have a traditional vent connection nearby. Other vent types serve different situations: a common vent handles multiple fixtures sharing one vent, a dry vent is used in configurations where the vent must stay dry above a horizontal run, and a relief vent provides an extra vent to protect traps in longer fixture runs.