The Glow-worm gas pipework can be listed in two categories. The external pipework that connects to the wall jig and allows gas to enter the appliance would be the first. Any plumbing in your unit that transfers liquids would fall under the second category.
Compatible with Glow-worm Flexicom
Technical specification
TypeTube and Flow LinkFinishMattColourBlackManufacturer Model No20020749Brand NameGlow-worm