CSLB Class B General Contractor's License Practice Exam

Indirect waste pipes with a length of less than 15 feet must have a diameter that is at least what measurement?

1. The diameter of the drain outlet

2. Half an inch

3. A complete quarter inch

4. One inch

The correct answer is: The diameter of the drain outlet

The correct answer is that indirect waste pipes with a length of less than 15 feet must have a diameter that is at least the diameter of the drain outlet. This requirement ensures that the waste can flow freely without creating any blockages or back pressure in the system. In plumbing systems, the size of the waste pipe is critical to maintaining proper drainage and preventing issues such as backups or inadequate flow rates. By matching the diameter of the indirect waste pipe to the drain outlet, the system can accommodate the volume of waste being discharged effectively, which is particularly important when dealing with non-potable fluids or condensate from equipment. Other options, which suggest specific measurements like half an inch, a complete quarter inch, or one inch, do not provide the flexibility required in different systems where drain outlets can vary significantly in size. These fixed measurements may not be sufficient for certain applications, especially in larger systems or where plumbing codes specify different requirements based on the type of fixtures or the overall design of the waste management system.