What is the minimum trap size specified for serving an automatic clothes washer?

What is the minimum trap size specified for serving an automatic clothes washer?

• A. 2 inches
• B. 1-1/2 inches
• C. 3 inches
• D. 1 inch

Answer: (A)

The main idea is that fixtures with a high discharge rate need a larger trap to handle the flow and prevent problems like siphoning or clogs. Automatic clothes washers dump a large volume of water into the drain quickly, so the trap must be big enough to allow that water to pass without pressure build-up or premature clogging. That’s why the minimum trap size for serving a washing machine is two inches. Smaller traps, like 1-1/2 inches or 1 inch, can restrict flow and are more prone to blockages under the washer’s surge of water.

The main idea is that fixtures with a high discharge rate need a larger trap to handle the flow and prevent problems like siphoning or clogs. Automatic clothes washers dump a large volume of water into the drain quickly, so the trap must be big enough to allow that water to pass without pressure build-up or premature clogging. That’s why the minimum trap size for serving a washing machine is two inches. Smaller traps, like 1-1/2 inches or 1 inch, can restrict flow and are more prone to blockages under the washer’s surge of water.