PDF Ltd. can provide site spark testing to GRP, Rubber and plastic tanks and pipes.
PDF Ltd. can provide high and low voltage spark testing on painted; glass lined or coated pipes and vessels to detect damages of interior coating applications on surfaces. A test voltage is applied to the coating by moving a brush probe across the surface and where there is either a pinhole or flaw, the voltage will spark through the coating at the flawed location, a red flashing indicator will flash and an audible alarm will sound. The detected flaw can now be marked for subsequent repair and testing resumed for the remaining surface area. If no flaws are detected the test will therefore be non-destructive.
The value of the test voltage is determined by the dielectric or voltage strength of the coating thickness. As a rough guide the test voltage can be approximated between 3 to 5 volts per micron of coating thickness, therefore 1000 micron would be approx 3kV to 5kV test voltage.
The purpose of the test is to determine the presence of pinhole leaks, punctures, cuts, etc., that expose passages to the base metal. Please note that a spark test is not complete without a full and thorough visual inspection of the entire lining completed at the same time as the spark test itself. Spark testing is not an absolute test, meaning that it is not 100% fail safe. Technique, visual inspection, equipment maintenance and rubber lining application experience are all essential in reducing errors, misinterpreting results and completing the spark test with meaningful result.
Contact PDF Ltd. to discuss your Spark testing, Hardness Testing Needs and Requirements.