Final answer:
In plumbing for high-rise buildings exceeding 11 stories, a yolk vent is used to balance the pressure within soil or waste stacks to prevent issues like siphonage and back-pressure.
Step-by-step explanation:
The question refers to the plumbing requirements for high-rise buildings, specifically about venting solutions for soil or waste stacks that receive discharge from fixtures located on more than 11 stories. In plumbing engineering, a yolk vent is a remedial venting method used to balance the pressure within stack systems in high-rise buildings. When a building exceeds 11 stories, the complexity of the wastewater system increases, and special venting methods like a yolk vent are necessary to prevent problems such as siphonage (which can empty traps) and back-pressure. The yolk vent is typically connected at intervals within the stack, assisting with the balancing of pressure and ensuring the continuous operation of the drainage system.