Validation procedure
• Before each circuit is passivated, it must be ensured that the surfaces of stainless steel are clear from oil and grease by taking a 100 ml sample of the pre rinse water in a scrupulously clean beaker and adding a small amount of analytical grade granular camphor. If there is no grease or oil remaining the camphor granules will dance over the surface, conversely if there is oil or grease present the granules will remain static. This test is very sensitive ie. A greasy fingermark on the beaker s internal surface will affect the outcome, hence where new water service mains are being used the rinse water should be checked to ensure that it is oil and grease free prior to using it for CIP rinsing purposes.
• If the circuit is clear from oil and grease , it will be released for passivation. Before starting of passivation, sample of stainless steel surface, short piece, will be hang in CIP object or soaking in sampling solution depend on possibility and safety. This sample of stainless steel surface is the representative of the pipe surface and tank and it will be tested by spot ferroxyl method at the end of process.