What is the general acceptance criterion for a pass in a typical tank tightness test?

What is the general acceptance criterion for a pass in a typical tank tightness test?

• A. The leak rate must be at or below the regulatory/ICC-specified allowable limit for the tank type
• B. The tank must be completely dry on the outside
• C. The test duration must be less than five minutes
• D. The pressure must rise above a fixed threshold

Answer: (D)

In a tank tightness test, the essential check is that the system can be pressurized to a defined test level. The procedure sets a fixed threshold pressure, and reaching above that threshold shows the tank and its seals can hold the required pressure without obvious leakage paths. If the pressure cannot rise to or exceed this level, or falls away too quickly, it signals leakage or faults that fail the test. After achieving the threshold, the test may continue to monitor for any decay to quantify leaks, but the primary, objective pass signal is reaching and maintaining that preset pressure. The other factors—drying the exterior, short test duration, or a mere implied rise in pressure—do not provide the same clear pass criterion on their own.

In a tank tightness test, the essential check is that the system can be pressurized to a defined test level. The procedure sets a fixed threshold pressure, and reaching above that threshold shows the tank and its seals can hold the required pressure without obvious leakage paths. If the pressure cannot rise to or exceed this level, or falls away too quickly, it signals leakage or faults that fail the test. After achieving the threshold, the test may continue to monitor for any decay to quantify leaks, but the primary, objective pass signal is reaching and maintaining that preset pressure. The other factors—drying the exterior, short test duration, or a mere implied rise in pressure—do not provide the same clear pass criterion on their own.