Some chemical plants have crystallizer
pipes which have a stainless steel (non-ferrous) pipe inside of a carbon
steel (ferrous) pipe. Low Frequency Electromagnetic Technique (LFET) must
be used due to the stainless bieng surrounded by carbon steel.
TesTex has developed a special probe which focuses on just the stainless
steel pipe. This allows us to test for wall loss, pitting, and cracking
in the pipe. The use of LFET allows for only the penetration of the stainless
steel pipe with no interference from the carbon steel pipe.
Due to the different probe configuration, LFET focuses its magnetic lines
of force such that the magnetic flux never leaves the proximity of the
stainless steel pipe being tested. |
