Vent pipes protect trap seals from ________.

Vent pipes play a crucial role in plumbing systems by helping to maintain atmospheric pressure in drainage systems. One of their primary functions is to protect trap seals from becoming compromised. Trap seals are the water barriers in plumbing fixtures that prevent sewer gases from entering living spaces.

By providing venting, these pipes allow air to enter the drainage system, which helps to equalize pressure. When negative air pressure occurs (often when water flows down a drain), it can siphon or draw water out of the traps, leading to a loss of that protective water barrier. This loss can allow harmful sewer gases to escape into the home or building.

Therefore, the correct answer focuses on how vent pipes mitigate the risk of vacuum creation within the plumbing system, thereby safeguarding the integrity of trap seals and ensuring that they remain effective in blocking sewer gases. Understanding this role of vent pipes is essential for maintaining a safe and functional plumbing system.