What is the minimum size tailpiece or trap for a kitchen sink with a dishwasher?

What is the minimum size tailpiece or trap for a kitchen sink with a dishwasher?

• A. 1 1/4 inches
• B. 1 1/2 inches
• C. 1 inch
• D. 2 inches

Answer: (B)

Ensuring enough flow capacity is the key. A kitchen sink drain, especially when a dishwasher is connected, needs a trap and tailpiece large enough to handle the higher volume of water without backing up. The standard minimum for a kitchen sink setup with a dishwasher is 1 1/2 inches. That size provides the necessary drainage capacity and helps prevent siphoning of the trap seal. Smaller sizes like 1 inch or 1 1/4 inch can restrict flow and lead to clogs or backups, while 2 inches is larger than the typical minimum and not required for a standard residential setup.

Ensuring enough flow capacity is the key. A kitchen sink drain, especially when a dishwasher is connected, needs a trap and tailpiece large enough to handle the higher volume of water without backing up. The standard minimum for a kitchen sink setup with a dishwasher is 1 1/2 inches. That size provides the necessary drainage capacity and helps prevent siphoning of the trap seal. Smaller sizes like 1 inch or 1 1/4 inch can restrict flow and lead to clogs or backups, while 2 inches is larger than the typical minimum and not required for a standard residential setup.