In an automatic line leak detector, what is the specified leak rate?

• A. 2 gallons per hour
• B. 3 gallons per hour
• C. 4 gallons per hour
• D. 5 gallons per hour

Answer: (B)

A maximum allowable leak rate is set so a line passes the test if the actual leak rate is at or below that limit. For automatic line leak detectors in tank tightness testing, the standard threshold is three gallons per hour. This balance keeps safety and environmental protection in check while staying realistic for typical equipment and installation variations. A tighter limit (like two gallons per hour) would make passes rare and could cause unnecessary failures, whereas looser limits (four or five gallons per hour) would let more significant leaks slip through, reducing safety. So three gallons per hour is the most appropriate and commonly used specification.