04:12 Jul-27-2000 N.Kuppusamy Consultant Hi-Tech NDT Inspection Services (S) Pte Ltd, Algeria, Joined Jul 2000 4
Hydrogen Induced Cracks (HIC)
I worked for Suadi Aramco and inspected pipes & elbobws for HIC related problems. We don't have control on HIC. If you find HIC, then monitor it periodically. Since it is related to inter granular craking, you have to monitor it periodically for the time period ranging from 6 months to 2 years depends up on the rate of HIC propagation. First you schedule your 2nd inspection after 6 months and find out the rate of propagation.
If the rate of propagation is less than 14mils per year in depth, then yoy can schedule your next inspection after 2 years. If the rate of propagation is more, you can reinspect it after some time period, depends up on the rate of propagation.
When the depth of HIC reaches the minimum required design thickness criteria described by ANSI, you can replace that partivcular spool.