Common questions about Flexigas.

Flexigas is flexible corrugated stainless-steel gas pipe, known as CSST. Instead of soldering rigid copper around every obstacle, you route one continuous flexible 316L stainless tube, with far fewer joints and no hot works at the seal.

DN15, DN22, DN28, DN32, DN40 and DN50, the same notional bores as copper. It comes in coils from 15m up to 400m, so most domestic runs can be pulled in one continuous length. See the full range.

A 316L stainless-steel corrugated core with a yellow flame-retardant polyethylene cover. The cover is UV stable and tested for direct burial.

Flexigas is built for a 100+ year design life, backed by a 25-year manufacturer warranty against manufacturing defects when installed by a Gas Safe registered engineer to Flexigas guidelines.

They are all CSST, but they are not interchangeable. Flexigas tubing only ever connects to Flexigas fittings. Joining different CSST brands together is forbidden and voids the BSI Kitemark and your warranty, however similar the systems look.

No. A wheel metal pipe cutter, a utility knife and two spanners. No press tool, no soldering kit, no jointing compound. The corrugated tube self-flares against a brass seat to make a dry, metal-to-metal seal.

Yes. Standard Flexigas can be buried without extra sleeving, provided the cover is inspected, any damage is wrapped with silicone tape, and minimum cover depths are met: 375mm in gardens, 475mm under light traffic, 600mm under heavy traffic. Fittings are never buried.

Never within the cavity itself. Pipework passing through a cavity wall takes the shortest practicable route and is sleeved. It can run within the wall structure (in a timber-frame channel, or behind 1mm steel plate within 50mm of the plasterboard face).

Standard Flexigas, yes, in non-structural screed with minimum 25mm cover above the tube, and no fittings within the screed (use a conduit junction box if a fitting is genuinely needed). Never in structural slabs or power-floated floors.

Main equipotential bonding is a single connection per BS 7671, made as near as practicable to the point of entry, before any branch. The integrated FG Bond terminal makes that bond faster, but you are not bonding every joint.

Use the in-browser sizing calculator or the tables in the install guide. Note that pressure loss in Flexigas is slightly different to copper, so you cannot just swap like-for-like at the same diameter, calculate it.

Yes. Flexigas is BSI Kitemarked under licence KM 598726 and manufactured to BS EN 15266:2007, the standard for stainless-steel pliable corrugated tubing for gas, with fire performance tested to EN 1775.

All gas work in the UK must be carried out by a Gas Safe registered engineer holding a valid ACS or NVQ/SVQ certificate, in accordance with the Gas Safety (Installation and Use) Regulations 1998.

Installed in accordance with BS 6891:2015 for DN15 to DN32 and IGEM/UP/2 for DN40 and DN50, bonded to BS 7671, with gas tightness testing to IGE/UP/1B. Maximum operating pressure is 0.5 bar.

No. Soaps with a high chloride content corrode stainless steel and brass over time. Use only a non-corrosive leak detection fluid suitable for stainless steel.

Flexigas is stocked by merchants across the UK. Use the stockist finder to find your nearest branch by postcode. If there is nothing close by, talk to the team and we will arrange the best way to get product to you.

Yes. We set branches up with a stocking pack, trade pricing and trade-morning support. See becoming a stockist.

Yes. We run hands-on trade mornings for installers and in-merchant sessions for branch teams. See training. Note that FlowFlex adapter fittings require a short certified session before use.