4.8 Precision Tightness Testing (PTT)
PTT is a method of tightness testing designed to meet the more stringent requirements related to testing for a leak from ANY portion of a UST or testing the integrity of piping systems at 150% of operating pressure.
PTT methods perform both types of testing at the US EPA and Commerce specified leak rate of 0.1 GPH. PTT is required for verifying various conditions of the UST system.
PTT is used to:
Verify monthly ATG 0.2 GPH tightness “fail” test results for tanks
Verify ATG 0.2 GPH and 3.0 GPH leak rate “fail” test results for piping
Verify failed and/or inconclusive monthly test results from SIR
Verify leak alarms from secondary containment monitoring systems for tanks and/or piping
Verify the integrity of tanks and/or piping prior to startup
Verify the tightness of tanks whenever the UST owner or operator fails to provide monthly inventory control records for the previous twelve (12) months, or provides inconsistent inventory control data during any two (2) consecutive months
Perform annual 0.1 GPH tightness testing of product piping for compliance with Comm 10 requirements