CSST gas line coupling

OK , so I have a question for all you inspectors out there. I called this out as an incorrect coupling as there is a correct one available. The homeowner had a plumber inspect and they stated that this is “typical” and that it passed the original inspection, and that there is nothing wrong.
What do you all think??

What does the manufacturer say about couplings and splices?

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Brass threaded fittings are used on either side of the coupling… non-issue.

Plastic support hanger is broken… CSST not properly supported.


I don’t see a problem with the coupling. CSST is mixed/transitions to black pipe all the time.


Looks good from here.


All materials are approved for fuel piping, right?


Looks good from Ohio.
I also like the fact they used teflon tape between the dissimilar metals. :+1:

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it looks good from the north coast of Ohio also…

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I do appreciate all the feedback and the information.


Correct me if I am wrong but, I see CounterStrike® tubing by OmegaFlex. This CSST flex pipe is up to 400 times more resistant to the damaging effects of electrical energy than yellow CSST.

The union does not appear to be manufactured from Brass, an alloy of copper & zinc, for durability, corrosion resistance, and high electrical conductivity. It is a BIS rigid pipe nipple left/right hand threaded couple, manufactured from galvanized steel or cast iron, which may affect durability, corrosion resistance, and high electrical conductivity. If this is the case; a: there will be galvanic corrosion due to dissimilar metals unless joint faces are insulated with non-conducting gaskets & grommet-type fasteners. Even then the CounterStrike® manufacture might prohibit such use.

You asked for it.

There is no union in the photograph.

It appears to be a normal approved malleable iron coupling. What makes you think it’s a right hand left hand thread coupling?

There will not be. CSST tubing can have iron pipe in the same system with no issues. Even the manufactures manifold is made of malleable iron.


What would the correct coupling be?

Iron not Brass.
Because they come in right of left hand threading and used on nipples or other threaded rigid or flexible pipes.

I concur with your position.

The only problem is the brass CSST male adapter only come in right hand threads. The installer would have a hell of a time installing that in a right hand left hand malleable iron coupling.

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As I understand it, galvanic corrosion is not really an issue on indoor gas lines, as you do not have an electrolyte (water).

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Yes they come in left and right hand threads. That is all I was stating. Not one end is left handed and the other end right hand threading.

Proper pipe Bonding may be affected. 1: Dielectric fitting is required. Dissimilar metals. If there is no dielectric fitting galvanic corrosion can precede.
Hope I am making sense.

Good point.
Ambient Moisture as well as Bulk Water.

You absolutely were stating that the union, which is really a coupling, was a right hand left hand union. I’ve put miles of this pipe in and had access to the factory catalog and I can tell you at the time there was no right hand left hand couplings.

The reason is every fitting is in itself a union. You can cut a tee or an elbow anywhere in CSST tube and put it together. It is not like threaded iron pipe where you start from the supply to the fixture and only use right hand threaded fittings and pipe.

Waiting for your reply because I know even when you’re wrong you still reply with some BS fact that somehow you’re right.