Internal Corrosion has been always a great challenge in many process industries. Corrosion monitoring and proper mitigations are vital in most of the industries especially in the Oil and Gas productions. On line Corrosion monitoring (OCM) techniques have been extensively used to monitor internal corrosion of the coupons installed in the process equipment in order to assess the corrosively of the fluids and monitor the internal corrosion of the equipment. OCM coupon corrosion/pitting rates provide the inputs for conduct the Nondestructive testing (NDT) of the equipment’s to verify actual thickness reductions due to corrosion in order to prevent any failure.A case study is conducted for this paper in one of the gathering centers (GC) of Kuwait Oil Company’s facility. Very severe general/pitting rates shown by OCM points and by the verification of using long range ultrasonic thickness (LRUT) testing it was found that severe thickness reductions of the piping. The piping portion which showed severe thickness reductions was replaced. Detailed investigations were carried out on the failed pipe sections to analyze the cause of corrosion and issued proper recommendations for mitigation measures.This paper describes the benefits of OCM techniques co-relation of OCM corrosion/pitting rates replacement of piping prior to failure and corrosion investigations of the piping which was mostly due to the heavy deposits and under deposits microbiological influenced corrosion(MIC).Key Words: On line corrosion monitoring (OCM)Nondestructive Testing(NDT) microbiological influenced corrosion(MIC).