Home-Flex: What Is CSST Pipe? A Look at Corrugated Stainless Steel Tubing

CSST (Corrugated Stainless Steel Tubing) is a flexible, stainless-steel gas piping system with a protective jacket. Brands like Home Flex and TracPipe use long, continuous runs with far fewer fittings than traditional black iron—speeding up installs and reducing potential leak points.

CSST vs. Appliance Connectors

CSST is permanent gas piping that runs through walls/ceilings and terminates at a stub-out with a shutoff valve. A flexible appliance connector is the short, braided line from that valve to the appliance. They’re not interchangeable.

Why Choose CSST?

• Faster installs: Fewer joints and easier routing around obstacles.
• Fewer leak points: Long continuous runs reduce threaded connections.
• Lightweight & flexible: Ideal for remodels, attics, and manifolds.

When CSST Is the Better Fit

Safety Essentials (Read Before You Buy)

• Bonding: CSST systems must be bonded to the building grounding electrode with an appropriately sized conductor (commonly #6 AWG copper). Attach the bonding clamp to rigid gas piping or the manifold per the manufacturer—never to the CSST itself.
• Protection: Use striker plates where tubing passes through studs; sleeve where it penetrates masonry; avoid sharp edges and tight bends.
• Support: Follow brand instructions for hangers and spacing (typically every 4–6 ft and at changes of direction).
• Pressure test: Cap and test per code/manufacturer before putting into service.
• Outdoors/underground: Only with products listed for that use and installed in conduit with tracer wire where required.

How to Size CSST (Quick Method)

1. Fuel & pressure: Verify NG (≈7" w.c.) or LP (≈11" w.c.) and allowable pressure drop (often 0.3–0.5" w.c.).
2. Total BTU load: Add appliance inputs on each branch; identify the longest run to the highest-demand appliance (“longest length” method).
3. Use the brand’s table: Match nominal size to capacity at the run length (Home-Flex/TracPipe tables show capacities by length). Choose a size where capacity ≥ BTU load.
4. Check fittings & valves: Keep transitions minimal and sized to avoid choking flow.

Install Tips for a Clean, Code-Friendly Job

• Terminate to a rigid stub-out with a listed gas shutoff valve at the appliance location.
• Use brand-specific fittings only; tighten to torque spec and don’t reuse gaskets.
• Keep bend radius gentle (manufacturer minimums) and avoid kinks—replace if damaged.
• Label the manifold and leave a copy of the layout for future service.

Note: Installation requirements vary by jurisdiction. Always follow the manufacturer’s manual and local code.