What is the size of the vent pipes for the lavatories and urinals in Room 009?

The size of the vent pipes for lavatories and urinals in Room 009 is specified as 1 1/2 inches. This size is standard for providing adequate ventilation to plumbing fixtures like lavatories and urinals, allowing for proper drainage and preventing the buildup of sewer gases. Vent pipes help maintain neutral air pressure in the drainage system, which ensures that wastewater flows smoothly without creating siphons that could draw water out of the traps, leading to potential odors and drainage issues.

While other sizes could theoretically be used for different types of fixtures or applications, 1 1/2 inches is the typical requirement for the plumbing standards concerning smaller fixtures like lavatories and urinals. This dimension allows for efficient venting without being overly large, which could take up unnecessary space or be impractical for design considerations within the structure.