# Use of corrugated stainless tubing for hooking up gas fireplace?



## webbie (Jun 3, 2008)

I notice many new houses are using the flexible plastic coated stainless gas piping for ALL interior piping, yet the instructions for my gas fireplace say to only use black iron pipe.

When we installed gas fireplaces we used 100% black pipe as the newer stainless was not yet popular.

So, if any here are installers or in the trade, it would be nice to know the common methods today to hook up gas to a DV fireplace. Is there a certain distance away from the unit where the stainless has to be terminated and then to black? Or can this stainless stuff actually go under the unit all the way to the shutoff located near the gas valve under the firebox?

Any hints welcome.


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## stoveguy13 (Jun 3, 2008)

Yes the SS flex has become common as you can use it on both LP and NG. it can go into the box just like the black cloud


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## webbie (Jun 3, 2008)

Thanks!

It appears I am a little behind the times and so are the owners manuals. The appliance manual does not mention these other options - just says iron must be used at the appliance.

I took some time and looked at the manuals on the brands of flex ss gas pipe - and, sure enough, they directly addressed gas fireplace and inserts and 100% allow the use of this stuff right to the valve.

In general, this ss stuff is being sold and used as equiv. to iron. Whether or not it is seems to be a point of contention among pros, but for now the fact that it passes the gas and building codes is good enough for me.

Another point seems to be that installers of this stuff must be trained and licensed to do so - although I'm certain many authorities fail to check!


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## Redox (Jun 6, 2008)

I was part of the old school that thought you had to use black steel on gas.  I'm proud to say I'm reformed now.  I ran a piece out to my standby generator as it would have been too hard to get the pipe around all the obstacles.  100% leak free on the first attempt!  It is more expensive, but the labor savings is incredible.  I don't think I'll ever go back now.  

I installed a gas log in our last house and the mfr. instructions seemed to prefer soft copper.  Almost all LP installs I've seen have been in copper and they (rarely) cause problems.  The only concern I've heard is that copper can work harden and get brittle.  I'm not sure this is a factor with SS.  I once had a "discussion" with one of our code authorities about the gas flex inside a furnace we were "twinning".  The kit was supplied by the manufacturer with a SS appliance connector, but he failed it anyway.  Local codes supercede and all that...

As long as the flex is installed properly, IE protected from physical damage, I don't see a problem.  I did make sure the flex was secured to the slab under the generator and ran the last few feet in steel to avoid piping vibration.  Ironically, the generator piping is all in glorified rubber hose inside the cabinet, but at least it's outside...

Chris


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## Chris S (Jun 7, 2008)

Big cost difference,  but the downside is you can'y hang clothed hangers on the CSST pie on the basement ceiling like everyone is accustomed to.

Chris


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## Redox (Jun 8, 2008)

They don't really like stuff hanging from the gas pipes anyway, but it wouldn't cost a lot to hang a piece of steel pipe just for the clothes.  It doesn't need fittings and have to be gas tight!

Chris


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## jtp10181 (Jun 9, 2008)

Everyone around here runs it right into the fireplace. I have not seen anything in our manuals prohibiting it.


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## DAKSY (Jan 6, 2009)

We run Trac-Pipe CSS for most internal gas lines. It's not approved (locally, anyway) for outside installations unless it's run in conduit (or black plastic for underground installs).
We've tried Ward-Flex & a couple of others & Trac-Pipe seems to owrk best for our installs...
Most of our new construction scenarios have the plumbing/heating KTRs run BIP to within 5' of where the gas fireplace will be located.
We make the final connection with Trac-Pipe..
Where the Trac-Pipe runs thru a sill or header plate, we hafta sheathe it in steel conduit. Some inspectors are making us run conduit thru masonry as well. The latest issue up here in snowy NY State is to ground all CSS to either the breaker panel or to a new ground stake.
Evidently a lightning strike caused an electrical arc - which burned a hole thru the CSS - which then led to a house fire - which led to a lawsuit...


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## dave11 (Jan 7, 2009)

The interesting point to me, having spent  a lot of time talking with local folks about this, is that many installers use CSST or soft copper when they install in other people's houses, yet tend to use black pipe when they install in their OWN house.

Hmm.

There has been a concern raised about soft copper reacting with the hydrogen sulfide in NG and flaking off, sometimes in less than ten years, which requires replacement of the pipe. I saw a report of some houses in CA that required replacement of their lines within six years of installation.

CSST and other flexible pipe, other than at the termination at the appliance, makes many people skittish. A careless carpenter can put a nail through it, and apparently the coverings on some of them are considered tasty by some dogs. And as was mentioned, proper grounding is key. 

When I re-plumbed my house for gas, I used all black pipe. It's also dirt cheap.


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## webbie (Jan 11, 2009)

Crawled under my vacation cottage the other day to see about water shutoffs...and there was that plastic coated Flex gas piping....with the condensate drain from the furnace dumping that acid water right on top of it! Brilliant plumbing. The condensate was also hitting a metal air duct........

whatever happened to common sense?


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## jtp10181 (Jan 11, 2009)

Anyone with the CSST (Corrugated Stainless Steel) gas lines in their house, make sure the gas pipe system is correctly grounded / bonded. Otherwise a lightning strike can ark and blow a hole in it. Its happened around here a few times.


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