The fixture supply pipe for women's restroom lavatories rated at 2 cwsfu each should be what size?

In determining the appropriate size for the fixture supply pipe for women's restroom lavatories rated at 2 cwsfu (clothes washing fixture units) each, it's important to understand the plumbing code and the calculations used for sizing supply lines.

A lavatory typically has a relatively low demand for water compared to other plumbing fixtures. When calculating the size of the supply line, the total fixture units need to be considered along with the distance from the source of supply, the anticipated flow requirements, and the pressure available.

For lavatories rated at 2 cwsfu each, using standard plumbing codes, one can refer to the prescribed tables that specify the required supply pipe sizes according to the total fixture units served. Generally, for low-demand fixtures such as lavatories, a 1/2" supply pipe is sufficient for providing adequate flow and pressure under normal conditions.

This capacity allows for the necessary water flow without excessive pressure drop, thus ensuring that the lavatories can function effectively—even if several are used at the same time. In light of these factors, a 1/2" supply pipe is the most appropriate size for this application.