If you are planning a gas line installation, you may have heard your contractor mention two types of pipe: black iron pipe and CSST (Corrugated Stainless Steel Tubing). Understanding the differences between these two materials will help you have a more informed conversation with your contractor and understand why one might be recommended over the other for your project.
What Is Black Iron Pipe?
Black iron pipe — also called black steel pipe — is the traditional material used for residential and commercial gas lines. It is made from steel with a black iron oxide coating (hence the name) and comes in standard lengths that must be cut and threaded on-site. Black iron fittings (elbows, tees, unions, and nipples) are used to make direction changes and branch connections.
Advantages of Black Iron Pipe
- Proven durability: Black iron pipe has been used in gas systems for over a century and has a well-established track record
- Impact resistant: Rigid steel pipe can withstand physical damage better than flexible tubing
- Lower material cost: Black iron pipe and fittings are generally less expensive per linear foot than CSST
- No bonding requirement: Unlike CSST, standard black iron pipe does not require a separate bonding/grounding connection
- Works in exposed locations: It is acceptable to run black iron pipe exposed in basements, garages, and utility spaces
Disadvantages of Black Iron Pipe
- Labor intensive to install: Each piece must be measured, cut, threaded, and assembled — a long run with multiple bends can take significantly more time than CSST
- Susceptible to corrosion: In areas with moisture exposure, black iron pipe can rust over time if not properly maintained or protected
- Rigid routing: Running black iron through walls, floors, and joists requires careful planning and more wall penetrations
- Heavier weight: The rigid pipe and fittings add significant weight to installations
What Is CSST (Corrugated Stainless Steel Tubing)?
CSST is a flexible, yellow-jacketed stainless steel tubing system introduced in the United States in the late 1980s. It is designed to be routed like electrical wire — threading through walls, floors, and joists with minimal straight runs and fewer fittings. Popular brands include TracPipe, CounterStrike, and Gastite.
Advantages of CSST
- Much faster to install: A single continuous run of CSST can replace dozens of individual black iron segments and fittings, dramatically reducing labor time
- Flexible routing: CSST bends around corners and through framing members easily, reducing the number of wall penetrations needed
- Fewer connection points: Fewer connections mean fewer potential leak points in the system
- Earthquake resistant: The flexible nature of CSST handles ground movement better than rigid pipe — an important consideration in earthquake-prone areas
- Lighter weight: Easier to handle and install, especially in overhead locations
Disadvantages of CSST
- Higher material cost: CSST tubing and proprietary fittings cost more per linear foot than black iron
- Bonding requirement: Standard CSST (yellow jacket) must be electrically bonded to the home’s grounding system to protect against lightning-induced arc damage — this adds cost and requires an electrician or qualified contractor
- Not for all exposed locations: CSST should generally not be run exposed in areas where it could be physically damaged (garages, mechanical rooms) unless protected
- Brand-specific fittings: CSST systems use proprietary fittings — you cannot mix and match brands
CSST Bonding: What You Need to Know
One topic that often comes up with CSST installations is electrical bonding. Standard CSST (the yellow-jacketed variety) must be bonded to your home’s electrical ground system. This protects against a phenomenon where a lightning strike near the home can induce an electrical arc that burns through the thin CSST wall and causes a gas leak or fire.
Some newer CSST products — notably CounterStrike by OmegaFlex — feature an arc-resistant jacket design that may not require individual bonding in all jurisdictions. Your contractor should be familiar with your local code requirements and specify the appropriate product.
In Utah, the International Fuel Gas Code (IFGC) governs CSST installations. Always confirm bonding requirements with your licensed contractor and local building department.
Which Is Better: Black Iron or CSST?
There is no single correct answer — the right choice depends on your specific project. Here is a simple guide:
Choose Black Iron Pipe When:
- The run is short and straightforward (e.g., connecting an appliance in an open basement)
- The line will be exposed and needs to be impact-resistant
- You want to minimize material costs on a simple project
Choose CSST When:
- The run is long or involves routing through multiple walls and floors
- Labor cost savings outweigh the higher material cost (common on runs over 20 feet)
- The installation is in a location with seismic risk
- Speed of installation is important (new construction or time-sensitive projects)
Many professional installations use a combination of both — CSST for the longer runs through the structure, transitioning to black iron at the appliance connections where rigidity and durability are preferred.
What Does The Gas Pipefitter Use?
At The Gas Pipefitter, we are experienced with both black iron pipe and CSST systems, and we use the material best suited for each specific project. We will always explain our recommendation and why — so you understand exactly what is going into your home and why it is the right choice for your situation.
Questions about your gas line installation options? Call us at (385) 316-9500 or request a free quote online. We serve Kaysville, Centerville, Bountiful, Layton, and all of Davis County, Utah.