What is the function of a yoke vent?

The function of a yoke vent is to prevent pressure changes in a stack. In plumbing systems, particularly those with vertical waste stacks, the yoke vent serves to equalize pressure within the stack. This is essential because variations in pressure can cause siphoning of water from traps, leading to drain issues and potential sewer gas entry into the building. By allowing air to enter the system, the yoke vent maintains atmospheric pressure, ensuring that the drainage system functions effectively without interruption.

Other functions listed do not accurately describe the role of a yoke vent. For instance, connecting waste systems or supplying water to fixtures does not pertain to the venting function, and directing waste away from the main sewer line is not within the scope of what a yoke vent is designed to accomplish. Understanding this specific role of the yoke vent is critical for maintaining proper plumbing function and preventing plumbing-related problems.