How can the 3 mm resolution criterion in direct integrity testing be met?
For pressure-hold test, this is simply a matter of applying a pressure high enough to overcome the bubble point of a 3 mm hole plus the backpressure and hydraulic head. The bubble point for a 3 mm hole is about 14 lb per square inch (psi) or 0.95 bars. For example, if a membrane system has no backpressure but has a 7-ft of hydraulic head in the membrane tank or module, the testing pressure to meet 3 mm resolution criterion is 14 psi + 7 ft x 0.45 psi/ft H2O = 17.2 psi. (~1.2 bars). This FAQ supplied by: Pall Corp.
