Yard hydrants should have what form of back flow protection?

• A. Dual check valve/ back flow preventer
• B. Air gap
• C. Backflow preventer with relief valve
• D. Vacuum breaker

Answer: (A)

Backflow protection for yard hydrants is about keeping any contaminated water from flowing back into the drinking supply when pressure changes or hoses are used. The best choice for a yard hydrant is a dual check valve/backflow preventer. Having two independent check valves in series stops both backpressure and backsiphonage, providing reliable protection for a simple outdoor hose connection. It’s a straightforward, cost-effective solution that many codes recognize for exterior bibs and often allows for convenient testing to ensure proper operation.

Air gaps are effective in some situations but aren’t practical or typical for hose bib installations. A vacuum breaker offers only limited protection and can fail under backpressure or freezing, making it less robust for routine yard hydrants. A backflow preventer with relief valve (RPZ) is a higher-hazard device used for more complex irrigation systems or chemical applications and is usually more than what is required for a standard yard hydrant.