Illinois Plumbing Code Practice Exam 2025 – All-in-One Guide for Exam Success!

The maximum length for a vent pipe according to the Illinois Plumbing Code is 50 feet without a cleanout. This specification is essential as it helps maintain proper ventilation and drainage within a plumbing system. A vent pipe serves the critical role of allowing air to enter the plumbing system, which helps equalize pressure and ensures that wastewater can flow freely.

If a vent pipe exceeds this length, the potential for blockages and pressure imbalances increases, which could lead to drainage issues or backpressure. The requirement for a cleanout is intended to provide access for maintenance and troubleshooting, ensuring the system can be kept clear and functioning properly. Thus, when a vent pipe is designed to exceed 50 feet, it should include a cleanout to assist in maintaining its effectiveness. This careful consideration of vent pipe length and accompanying provisions is instrumental for compliance with safety and operational efficiency standards in plumbing installations.