What role does a trap primer serve in plumbing?

A trap primer is an essential plumbing component designed to automatically maintain water in a trap, which is crucial for preventing sewer gases from entering a building. Traps, typically located in sinks, drains, and toilets, have a water seal that acts as a barrier to these gases. Over time, the water in the trap can evaporate due to a lack of use or other factors, which can compromise its effectiveness.

The trap primer addresses this issue by automatically introducing water into the trap at regular intervals, ensuring that the water seal remains intact and functioning. This function is vital for maintaining indoor air quality and preventing unpleasant odors or health risks associated with sewer gases.

In contrast, the other options refer to different plumbing concepts. Regulating water temperature in pipes pertains to temperature control mechanisms, filtering contaminants relates to water purification systems, and equalizing pressure involves devices that manage water pressure throughout the plumbing system. While all these aspects are important for overall plumbing function, they do not relate specifically to the primary purpose of a trap primer in maintaining the integrity of drain traps.