Which two fixtures do not require a strainer?

The two fixtures that do not require a strainer are the water closet (WC) and pedestal urinal. These fixtures are designed for direct waste removal and typically do not have standing water where debris might accumulate. The WC generally has a trap that prevents sewer gases from entering the living space, and it is specifically engineered to handle human waste and toilet paper, facilitating a straightforward waste flow without the need for a strainer. Similarly, a pedestal urinal is designed to flush away liquid waste without the requirement for a strainer since it is connected directly to a drainage system equipped to handle waste.

In contrast, other fixture pairs listed involve components that often retain excess water or allow particles to settle, which necessitates a strainer to catch debris and maintain proper drainage. For example, sinks, showers, and bathtubs are common plumbing fixtures that collect debris, necessitating strainers to prevent clogs and ensure smooth drainage.