Working on gas lines isn’t like fixing a leaky faucet.
It’s serious business — and choosing the wrong fittings? That can mean real danger.

Whether you’re planning a gas appliance hookup, extending a line, or just curious what your plumber’s using behind the wall — here’s what you should know about fittings for gas pipes.

First Things First: Know the Pipe Type

Before we talk fittings, we need to know what kind of pipe you’re working with. The most common ones in Sacramento homes are:

• Black iron pipe — traditional, strong, rigid
• CSST (corrugated stainless steel tubing) — flexible yellow-coated pipe
• Copper (rare for gas in California)
• Polyethylene (for underground exterior use)

Each one has its own type of approved fittings — and mixing them up can lead to leaks, failures, and code violations.

Common Types of Gas Pipe Fittings (And When I Use Them)

1. Threaded Black Iron Fittings

Used with rigid black iron pipe — the standard in older homes and most permanent installations.

Great for:

• Furnace and water heater supply lines
• Stove and dryer connections
• Longer, permanent gas runs

Not great for:

• Tight spaces
• Vibration-heavy areas (over time, threads can loosen)

Must use pipe thread sealant or yellow gas-rated Teflon tape for proper sealing.

2. CSST Fittings (For Flexible Gas Tubing)

CSST is easier to install in tight places, attics, or retrofits — but it requires its own manufacturer-approved fittings.

Great for:

• New construction
• Running lines through framing
• Appliance stubs

Only use fittings made specifically for the brand of CSST you’re using (TracPipe, Gastite, etc.)
Do NOT use standard plumbing compression fittings here — ever.

3. Flare Fittings

These are used at the end of gas appliance connections (like stoves or dryers), usually where a flex connector attaches.

Great for:

• Final appliance hookups
• Areas that need a bit of movement or vibration resistance

Must match the connector size (typically 3/8″ or 1/2″)
Over-tightening can damage the flare and cause leaks.

4. Transition Fittings (Iron to CSST or PE)

When changing from rigid pipe to flexible (like underground to indoor), you’ll need proper transition fittings.

These are often:

• Anodeless risers (for underground-to-above-ground connections)
• Flanged adapters
• Specialty couplings with gaskets and thread lock

These are critical points. Get them wrong, and your whole line is at risk.

What Not to Use

I’ve seen it all — and here’s what you should never use on a gas line:

• Standard water pipe fittings
• Brass compression fittings (unless specifically rated for gas)
• PVC or PEX
• Anything that isn’t clearly labeled gas-rated

Do You Need to Know All This as a Homeowner?

Not really.
But you should know enough to ask questions — and make sure your plumber isn’t taking shortcuts.

Ask things like:

• “Are those fittings rated for gas?”
• “Is this up to code for Sacramento County?”
• “Will this pass a pressure test if the inspector shows up?”

Any good plumber will be happy to explain. I always am.

What We Do at Golden Valley Plumbing

When we work on gas systems, we:

• Use only gas-rated fittings approved for the pipe type
• Pressure-test every job before relighting
• Pull permits if required
• Explain what we’re doing and why — in plain English

Not sure what fittings your system has? Call Golden Valley Plumbing — we’ll check your setup and make sure it’s safe, legal, and ready to go.

Final Word

Gas is no place to guess.

The right fitting can keep your family safe for 20+ years.
The wrong one can cause a disaster.

Always ask, always double-check — or just call a pro who knows the difference.