NASCLA Commercial General Building Contractor Exam — All Questions
Alltopics.nascla_procurement_contractingtopics.nascla_general_requirementstopics.nascla_site_constructiontopics.nascla_concretetopics.nascla_metalstopics.nascla_mechanical_plumbingtopics.nascla_woodtopics.nascla_thermal_moisturetopics.nascla_finishestopics.nascla_masonrytopics.nascla_doors_windows_glazingtopics.nascla_electrical
1 questions
topics.nascla_mechanical_plumbing
A commercial building's potable water system connects to an irrigation system. What device prevents contaminated water from being drawn back into the potable supply?
- a.A pressure-reducing valve
- b.A floor drain
- c.A backflow preventer✓
- d.A cleanout
A backflow preventer stops non-potable or contaminated water from siphoning or being pushed back into the potable water supply when pressure drops or reverses. Cross-connections like irrigation tie-ins are exactly where codes require backflow protection.Plumbing: backflow prevention