A 20-year-old LPG ball valve retrofitted with injection points

The valve and its duty

A 6 inch, 600 class ball valve worked on an LPG line. It was a spring-loaded, remote-operated valve, leaking from the stem.

Stem leaks often trace to worn packing or seals around the stem. Only inspection of the valve itself confirms the cause.

The valve was about 20 years old, and our survey found no injection points at all. Without them, there was no designed path into the stem sealing area.

That made online treatment impossible on the valve as found. A stem leak on LPG duty also releases product straight to atmosphere.

Many older valves were bought without any online service provision. The retrofit route exists for exactly this situation.

The intervention

A planned depressurised and degassed window was agreed for the work. The gas company hosting the premises approved the window jointly with the client. Fitting new points needed the valve depressurised, which is why the window mattered.

1. Existing bolts were replaced with sealant-injection fittings during the window.
2. Safety needle valves went in with the new injection fittings.
3. High-potency cleaner then went in through the new points.
4. Body-fill sealant followed through the same points.

Cleaning before sealant follows our standard order of work. Sealant should renew a clean sealing area, not cover debris.

A safety needle valve behind each fitting gives a controlled isolation point for future injection work.

The same gates apply to a retrofit as to any injection work. The valve design and its service must suit the fittings chosen.

The outcome and the record

The valve left the window with permanent injection points fitted.

It can now take online top-ups for the rest of its service life. Future stem treatment no longer needs a depressurised window.

The client had approved the rates in writing and directed priority execution. It later issued a purchase order recording the executed job.

A retrofit also changes how an old valve can be maintained. Routine care no longer has to wait for the next outage.

Our fitting retrofit guide explains when this route suits a valve. Browse more field results from planned window work.

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