Pass Rate Indictator

National Gas Services (NGS) and its service teams regularly complete valve maintenance to ensure the functionality and operability of their assets. To assess the condition of the valve seal, engineers usually ‘blow down’ the cavity of a closed ball valve, listening to the remaining flow from the vent port. While these tests are typically accurate, an engineer’s experience will always be intrinsically subjective, and the test cannot be repeated under the same conditions each time or in a different location.

To develop a tool that would counter these issues, we started the project by engaging with the field teams. By completing three separate field campaigns, we gained a deeper understanding of the requirements of the field operatives, and it became apparent that while the flow value was needed, what was more important was a quick and safe way to understand the current condition based on a 5 level asset health scale.

The PRI is a pragmatic solution, incorporating a small manifold that utilises a slight flow restriction and an existing NGS pressure gauge. With the geometry we designed in place, any flowing pressure above 1 bar can be converted to a flow rate using a linear equation. Supplied with the manifold, a conversion dial and user instructions, NGS and its service teams could start using PRI immediately to gain the accurate and repeatable results they need to ensure safe valve operation and optimal performance. This tool also allows NGS to check on the year to year condition of the valve and use this data to make informed investment decisions on repair/replacement plans.

NGS are now BETA trialling the PRI ahead of a national roll-out in 2024.