The postponement of planned shutdowns and maintenance increases the risk of unwanted incidents and longer shutdowns in the future.
IK-Group's mechanical isolation tool Add On Gate Valve (AOGV) can insert and retrieve an isolation spade on any live flanged connection, which allows you to isolate process segments for inspection and maintenance without shutdown.
This field-proven technology reduces time spent on maintenance, and the need for drainage, venting, purging and flushing is significantly reduced. The use of the AOGV technology also allows you to reduce your carbon footprint.
Increase uptime
For all assets, the execution of site activities should be done such that facility downtime is kept to a minimum, asset integrity is maintained and risk is mitigated to be as low as reasonably practicable. Built-in isolation points can require partial facility shutdowns and the ejection and flushing of large inventory volumes. Work scopes can come at a significant production loss and the more extensive the activity is, the more personnel are exposed. By using the AOGV mechanical isolation tool to bring the isolation points closer to the point of interest, the area impacted by the work is reduced, as is the likelihood of large ejection of process inventory or shutdown.
The AOGV provides positive isolation without any physical modifications or lasting impact to the process plant. Once the operation is complete, the flange pair is returned to its original state with a new gasket, bolts and nuts.
Cryogenic AOGV saves LNG plant from shutdown
On a major offshore LNG regasification plant, the operator needed to perform maintenance that involved the modification of a pipe section. The maintenance location was by the flare knockout drum where the natural gas was cooled to -260 degrees Fahrenheit.
Typically, this kind of operation is performed using isolation points that are built into the facility. However, as there were no suitable valves by the maintenance location and legacy isolation methods offered no viable solution, the operator was faced with having to shut down the facility, drain the inventory and restart the facility, incurring major costs, interruption of production and a complex shut down/restart operation with associated risks.
After carefully evaluating all possible solutions to address the challenge, the operator elected to use the AOGV mechanical isolation tool to provide positive isolation. The AOGVs were to be installed upstream on a knockout drum nozzle as well as downstream on a drain line, thereby isolating a minor section, whilst the main plant's process could continue.
Two three-inch ASME Class 150 cryogenic- rated AOGVs were commissioned for the job. The AOGVs were manufactured and assembled and extensive workshop testing was performed on them. The testing was witnessed by Notified Body - DNV® to ensure compliance with regulatory requirements and recognized standards, including appropriate testing with pressure and liquid nitrogen. IK-Group, in collaboration with the customer, planned the operation in detail involving logistics, HS&E and hazard identification, plus lifting and rigging requirements.
IK-Group's crew mobilized and performed a flawless operation where the AOGVs were installed to provide a zero-energy zone, enabling a complete replacement of the pipe section and valve replacement without any downtime.
In addition to experiencing zero nonproductive time and no HS&E issues, the customer eliminated the requirement for a shutdown of its facility, interruption of gas supply and avoided the costs of shutting down and restarting the facility. Compared with alternatives, the customer saved approximately 14 days of shutdown, which is significant for the 5-million- tons-per-annum terminal.
For more information, visit www.aogv.com or email Kenneth Låtveit at Kenneth.Laatveit@ik-worldwide.com.
