Which term designates the section of the fixture drain that runs from the trap to the vent?

Which term designates the section of the fixture drain that runs from the trap to the vent?

• A. Carrier Fitting
• B. Trap Arm
• C. Waste Arm
• D. Vent Stack

Answer: (B)

In drainage work, the pipe segment that leaves the trap and runs horizontally toward the vent is called the trap arm. It connects the trap outlet to the vented portion of the drainage system, and its proper function relies on being level enough to drain, yet sloped (typically about 1/4 inch per foot) so waste moves smoothly toward the vent. The vent stack is the vertical pipe that rises to allow air into the system, preventing siphonage of the trap. A waste arm is a term sometimes used for the drain portion after the trap that carries waste toward the building drain, but it’s not the segment from the trap to the vent. A carrier fitting refers to a specific type of fitting, not the length of drain between trap and vent.

In drainage work, the pipe segment that leaves the trap and runs horizontally toward the vent is called the trap arm. It connects the trap outlet to the vented portion of the drainage system, and its proper function relies on being level enough to drain, yet sloped (typically about 1/4 inch per foot) so waste moves smoothly toward the vent. The vent stack is the vertical pipe that rises to allow air into the system, preventing siphonage of the trap. A waste arm is a term sometimes used for the drain portion after the trap that carries waste toward the building drain, but it’s not the segment from the trap to the vent. A carrier fitting refers to a specific type of fitting, not the length of drain between trap and vent.