Patent ID: 6666970
Filing Date: 2003-12-23
Classification: B01D,G01N

Abstract:
A method of testing the integrity of at least one filter unit (11) having a hydrophobic filter (19) by a water intrusion test, comprising the following steps:(a) connecting said at least one filter unit (11) to a filter holder (15) capable of connecting to a multiplicity of filter units (11) and capable of incremental movement so as to present a multiplicity of filter units (11) one at a time to a plug-in station (9), (b) connecting said at least one filter unit (11) to a pressure tank (1) via said plug-in station (9) and a flexible pressure line that are in fluid communication with said pressure tank (1), said pressure tank (1) containing water at an initial predetermined test pressure under a cushion of gas; (c) reducing said test pressure in said pressure tank (1) to a value that is between 40% and 90% of the water penetration pressure for said at least one filter unit (11); (d) placing said pressure tank (1) in fluid communication with said feed inlet (10) so as to cause (i) water to flow into said inlet chamber (12) and (ii) the test pressure to diminish in said pressure tank (1); (e) introducing gas to said pressure vessel (1) for a predetermined first time period to increase the test pressure therein; (f) determining whether the test pressure in said pressure tank (1) is restored to its initial predetermined level within said first time period; (g) if the test pressure in said pressure tank (1) is not restored to its initial predetermined level within said first time period, omitting steps (h) and (i) and proceeding directly to step (j); (h) discontinuing the introduction of gas to pressure tank (1) after the test pressure has been restored to its initial predetermined level and after the elapse of a predetermined stabilization time period; (i) determining whether the test pressure is maintained or declines within a predetermined second time period; and (j) interrupting the fluid communication between said pressure tank (1) and said inlet (10) and releasing the connection between said at least one filter unit (11) and said pressure tank (1) by removing said at least one filter unit (11) from said plug-in station (9).