Home Builders Institute Pre-Apprenticeship Certificate Training (HBI-PACT) Practice Test 2026 – The All-in-One Guide to Master Your Certification!

A plumbing trap is designed specifically to prevent sewer gases from entering a building. This is accomplished by creating a water seal within the trap, which allows wastewater to flow through while blocking harmful gases that can pose health risks. Traps are typically found in fixtures like sinks, toilets, and tubs. The water in the trap acts as a barrier, ensuring that unpleasant odors and potentially harmful substances from the sewage system cannot escape into living spaces.

The other choices do not accurately describe the function of a plumbing trap. A device to increase water pressure relates to water systems but does not involve sewer gas prevention. A system to collect excess rainwater refers to drainage and rainwater management, which is unrelated to indoor plumbing traps. A filter to purify drinking water serves a different purpose entirely, focusing on ensuring water quality rather than gas prevention.