What portion of a fixture drain lies between the trap and its vent?

What portion of a fixture drain lies between the trap and its vent?

• A. Trap Arm
• B. Cleanout
• C. Vent Pipe
• D. Waste Arm

Answer: (A)

The part of a fixture drain between the trap and the vent is called the trap arm. This segment carries wastewater from the trap outlet toward the vent and must be properly vented to prevent the trap from being siphoned when water flows. Keeping the trap arm within proper length and slope ensures the vent can relieve pressure and maintain the water seal in the trap. For context, the waste arm is the portion that carries waste onward toward the building drain, while the vent pipe provides air to vent the system. A cleanout is simply an access point for clearing blockages. The key idea here is that the segment between the trap and the vent is the trap arm.

The part of a fixture drain between the trap and the vent is called the trap arm. This segment carries wastewater from the trap outlet toward the vent and must be properly vented to prevent the trap from being siphoned when water flows. Keeping the trap arm within proper length and slope ensures the vent can relieve pressure and maintain the water seal in the trap.

For context, the waste arm is the portion that carries waste onward toward the building drain, while the vent pipe provides air to vent the system. A cleanout is simply an access point for clearing blockages. The key idea here is that the segment between the trap and the vent is the trap arm.