Massachusetts Plumbers Journeyman Practice Exam

How many single compartment sinks or lavatories can be connected to one trap?

1. One

2. Two

3. Three

4. Four

The correct answer is: One

In plumbing systems, it is a requirement that a single compartment sink or lavatory is connected to a single trap to ensure proper waste disposal and prevent potential backflow or sewer gas leakage. The design of a trap is essential for maintaining the water seal that prevents harmful gases from entering living spaces. Each fixture must have its trap to allow for effective drainage and to ensure that each sink or lavatory operates independently, without interference from other fixtures. Connecting more than one sink or lavatory to a single trap can cause issues such as inefficient drainage, increased risk of clogs, and potential cross-contamination of waste between fixtures. This is why plumbing codes specifically dictate that each single compartment sink or lavatory should have its own trap, placing emphasis on maintaining the integrity of the plumbing system and ensuring sanitation.