VGO Heater Pass Scheduled Outage



Business Issue

This refinery was faced with performing their five year VGO outage in one-half the traditional time to minimize the impact on production.  There were eighteen control valves that needed to be repaired during the outage.  The refinery was faced with the challenge of repairing these control valves within a seven day window.

Project Summary

The heater pass control valves on the VGO unit do not have any by-passes so it is essential that all the control valves are repaired to “like-new” condition.  Based upon the available manpower, refinery maintenance knew there would not be enough time to perform the valve repairs in the traditional manner.  Typically maintenance would remove all eighteen control valves from the line and perform a complete rebuild in the instrument shop.

The ability to perform control valve diagnostic tests on the valves while they were still in the pipeline provided the opportunity for the refinery to meet their maintenance goals in the allotted time.  The Fisher Flowscanner diagnostic tool was used to perform these tests.  The Flowscanner quantifies the performance of each component of the control valve assembly.  This allows for the creation of an accurate and complete valve maintenance report.  The refinery’s technicians used these reports to perform the specific maintenance required to get the valve back to “like-new” condition.

After the repairs were completed, the Flowscanner was used to confirm and document the performance of each control valve at the time of the start up.

Scope Responsibility

Cornerstone Controls was responsible for the following areas:

  • Performed Flowscanner control valve diagnostics in-line to determine required maintenance for each valve
  • Acted as QC for the refinery’s maintenance technicians who performed the necessary repairs
  • Performed Flowscanner diagnostics on each completed control valve to verify and document “like-new” condition


All necessary repairs were completed on time in documented “like new” condition.  Project was completed 30% under budget compared to the traditional approach to these valve repairs.