What is the minimum size of a fixture water supply pipe for a domestic dishwasher?

The minimum size of a fixture water supply pipe for a domestic dishwasher is 1/2 inch. This size is specified to ensure that the dishwasher receives an adequate flow of water for proper operation. A 1/2 inch pipe is typically sufficient for delivering the required volume of water under normal pressure conditions in a residential setting.

Using a larger pipe size, such as 3/4 inch or 1 inch, could lead to unnecessary expense and bulkiness, as those sizes are typically reserved for main water lines or multiple fixtures. Conversely, a smaller size, like 3/8 inch, may not provide adequate water flow during operation, which could lead to inefficient performance or failure of the dishwasher to fill properly.

Thus, the 1/2 inch specification balances the needs for adequate water supply without incurring excessive costs or installation complications.