Hydrogen permeation measurements were used in the successful operation of a sour gas pipeline subsequent to a hydrogen-induced cracking (I-UC) failure in September 1992. Two joints of HIC-resistant pipe were used to repair the failed section and adjacent cut-outs. The pipeline has been operated for five years with no further instances of I-DC
failure. Hydrogen permeation monitoring was chosen as an integrity management ted because no techniques are currently available to inspect for I-IIC damage in a pipeline this size. Self-powered
electrochemical devices instafled on the pipeline were employed to monitor and control the effectiveness of a batch inhibition program in maintaining diffusing hydrogen atom concentrations below the Laboratory-meaaurcd threshold for initiation of I-UC damage. Permeation monitoring of a HIC-damaged refinery pressure vessel indicated very high hydrogen atom flux, despite attempts to inhibit corrosion with ammonium polysulfide injection. In this instance it was decided that replacement of the vessel was necessary.
Keywords: hydrogen sulfide, blisters, hydrogen-induced cracking, sour gas pipeline, refinery pressure vessel, hydrogen permeation monitoring.