ILTA Publishes White Paper on VRUs
An ILTA Working Group has completed work on a white paper describing a process hazard analysis of vapor recovery units and discussing mitigation options. ILTA opted to produce a white paper on this topic after it identified significant member interest following a Terminal Operating Practices Symposium (TOPS) presentation in September 2020. VRUs are used at petroleum loading facilities to control hydrocarbon emissions originating from all loading activities. These include, but are not limited to, truck loading, rail loading facilities, marine vessel loading docks, as well as tank degassing activities. As trucks and other vessels load liquid product, residual hydrocarbon vapors are pushed out of the vessel’s vapor collection system, into the terminal’s vapor line and to the vapor control device.
The paper discusses common issues within VRU operations, including tank overfill events, supply line failures and more. In the end, the working group provided several key takeaways:
Traditional configuration on the supply and return lines of VRUs has been identified as inadequately protecting against the potential for overfill of the VRU.
Mitigation measures include adding a redundant fail close valve. This redundant valve can be actuated in either the same or different method than the primary FC valve. In either case, position monitoring should be employed to give advanced notice to operations of an issue with the operation of the valves.
Newer fail close valves using supercapacitors and servo motors - rather than a spring - may be employed to remove the typical failure mode (fail close spring breakage) of the traditional actuators.
Mitigation measures are only effective with a robust maintenance program. This maintenance should include routine leak checks of each isolation component on the liquid side of the VRUs, verifying testing of these components is completed correctly, and monitoring UPS life.
After logging into your ILTA membership account, you can access the paper here.
The effort was led by Greg Johnston, vice president of operations at Lucknow-Highspire Terminals, with help from Marissa Karl (Buckeye Partners, LP), Kevin Snyder (Marathon Petroleum Company), Steve Sullivan (CITGO Petroleum), Marty Summers (Energy Transfer) Cheryl Tate (Energy Transfer) and Jon Zadzora (Lucknow-Highspire Terminals).
ILTA thanks all that worked on this important effort.