What happens during spark testing?

During spark testing, the entire glass-lined surface is inspected and any chips, cracks, pinholes and other defects should be documented and marked. It is important to carefully inspect nozzles and other internal attachments, as these areas are extra susceptible to damage. There are two apparatuses available for spark testing:

• DC spark testers – preferred method, portable and less hazardous; requires vessel to be grounded
• AC spark testers – must be used when examining removable agitators and other equipment that are completely glassed and can’t be grounded

Repaired areas should be avoided during this procedure as the voltage from the spark tester can damage the PTFE (instead, repair areas are inspected thoroughly during the visual examination). Due to the residual charges that build up during this procedure, spark testing should be the last test conducted before exiting a vessel.