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CSST - Pass or Fail?

2009 Fuel Gas Code: 407.2 Design and installation. Piping shall be supported with metal pipe hooks, metal pipe straps, metal bands, metal brackets, metal hangers or building structural components, suitable for the size of piping, of adequate strength and quality, and located at intervals so as to prevent or damp out excessive vibration. Piping shall be anchored to prevent undue strains on connected appliances and shall not be supported by other piping. Pipe hangers and supports shall conform to the requirements of MSS SP-58 and shall be spaced in accordance with Section 415. Supports, hangers and anchors shall be installed so as not to interfere with the free expansion and contraction of the piping between anchors. All parts of the supporting equipment shall be designed and installed so they will not be disengaged by movement of the supported piping.

I might fail this one because the conduit clamps used are too small, and the CSST stretched too tight. I have never read the MSSSP-58 document.
 
I'm not a CSST expert, but is it OK for the jacket to be cut that far away from the connections and not wrapped, especially where clamped?

Edit: originally mentioned concern about tee, but I think that's OK.
 
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Is that a galvanized tee in their CSST piping?.....What about dissimilar

metals?......Yes! There are too many tubing ridges exposed. :eek:

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It is a GasTite system. The questions I had on site (was there for framing, but saw this while I was crawling around):1. Can the plastic be removed that far back.2. Are the brass fittings compatible with the galvanized tee (natural gas, btw)3. Is there any issue with the location of the strapFrom what I have found so far:1. Removing that much plastic does not appear to be a problem. The instructions say to remove the plastic back 2 corrugations, but then says the capturing of the plastic in the retaining ring is not necessary. It also only mentions sealing the exposed CSST when it is outside.2. I cannot find anything in the manufacturer's instructions prohibiting galvanized fittings.3. Strap is suitable for the pipe, however pipe should not be exposed to sharp edges. I believe the strap should be relocated further back onto the plastic coating (would also solve any potential dissimilar material issues)

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Galvanized pipe typically is rated for use with natural gas, though black iron is less expensive. The brass CSST fittings are fine with the tee. The problem I see with the install is that the clamps bind a tightly stretched length of CSST, leaving a likelihood that the CSST will become ruptured, and no room for expansion and contraction.
 
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From the Gastite Design and Installation Guide, August 2010 Edition, Page 55:

http://www.gastite.com/include/languages/english/downloads/pdfs/Gastite_D+I_Guide.pdf


4.3 Routing

4.3.1 Vertical Runs

Vertical runs are the preferred run method.....Tubing runs should be relatively

plumb and free to move within the wall cavity without any physical support

between the floors......For support requirements refer to Section 4.1.....Where

any run is greater than two stories or 20-ft, additional support ( appropriate

to the weight of the tubing) must be provided at the point of penetration

through the floor......Care should be taken when installing vertical runs to

maintain as much separation as reasonably possible from other electrically

conductive systems in the building.......There is no requirement to maintain

​
separation from other electrically conductive systems when routing FlashShield



™

​


4.3.2 Horizontal Runs

​



Tubing routed on top of ceiling joists and other structural members which comply

with the horizontal support spacing requirements will be considered sufficiently

supported.......See Figures 4-28, 4-29, 4-30 and 4-31 for examples of acceptable

support configurations when routing Gastite ®/FlashShield™. Gastite®/FlashShield™

​
may be routed beneath, through and alongside floor and ceiling joists....Due






consideration must be given to future construction possibilities.......Horizontal runs

​
in concealed areas must conform to Section 4.4 Protection......Care should be taken

when installing horizontal runs to maintain as much separation as reasonably




possible from other electrically conductive systems in the building......There is no




requirement to maintain separation from other electrically conductive systems when



routing FlashShield™.

​





Tim,




In your 2nd picture, there are way too many exposed ridges......That would be a



location that is considered [ by Gastite ] to be an "electrically conductive" location.

​




I would fail that part of the install!

​


* * * *

​
 
Tim,

I don't see any problem with the amount of plastic sheild that is removed either. Where the manual states that it must be cut two corrugations back, this keeps the plastic from getting into the fitting where it might create a problem with the way the split fittings need to fit together. If the plastic gets into the split fitting area, it can create a tapered position of the split fittings and affect the shape of the seal.

Per section 4 of the manual, it states that the outer shield must remain in place as much as possible in outdoor installations. If the piping is installed indoors, I wouldn't have any problem with it the way it is (in either picture). I used to be a certified installer of Gas Tite, and have attended quite a few manufacturerer sponsored seminars, and the local building departments would attend as well. These kinds of issues came up regularly in the discussions.

I have to ask though, in pic #2, what in the world is it connected to? It looks like a meter bar in a crawl space(?)
 
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Glennman CBO stated:

I don't see any problem with the amount of plastic shield that is removed either. Where the manual states that it must be cut two corrugations back, this keeps the plastic from getting into the fitting where it might create a problem with the way the split fittings need to fit together. If the plastic gets into the split fitting area, it can create a tapered position of the split fittings and affect the shape of the seal."
Click to expand...
Recently, our BO association had a Gastite engineer come and speak to us on this very topic......Because of the classaction lawsuit brought against the various CSST manufacturer's, this particular engineer stated that the tubing

should not be exposed too much, because it would provide a location of ' arcing ', ..." IF / when " the piping

were to become energized by lightning.....He aslo emphasized the need for bonding of their gas system piping, ...as

is required in G2411.1 of the IRC.

* * * *
 
north star said:
* * * *this particular engineer stated that the tubing

should not be exposed too much, because it would provide a location of ' arcing ', ..." IF / when " the piping

were to become energized by lightning.....

* * * *
Click to expand...
No offense, but to turn this job down because of the possibility of arcing in the event of a lightning strike resulting from the small amount of plastic shield that is removed seems ludicrous in this circumstance of connecting CSST to iron pipe with brass fittings. I agree that the intent of the directive is to ensure that the shield in no way interferes with the fitting assembly.
 
That's a meter in a basement. CSST is not bonded (yet), walls are still open and the lines are still open.

I think it is a workmanship thing more than anything else. I stopped by today to see what the plumber had told the GC.. he said they remove it that far so they can slide the flare nut back over the tubing.. lame excuse but I don't see it as a violation.

I asked them to move the galv strap off of the stainless and onto the protective sleeving.
 
Jobsaver,

When I used to install this stuff, I always installed the strap over the plastic becouse it would sort of "grip" the plastic better, and I always thought that it would be better than on the steel due to the possibility of electrolysis, but that's just me.

I agree also with the ludicrousness of the arcing bit (no offence to any who don't). The engineer would need to provide a definition of "too much" (removed plastic).

Is it ok to remove 1" but not 3" or 6"? If you notice in the pictures provided in the manual, it shows sections of flexible metalic conduit installed to protect the CSST. This conduit is installed so that it is in contact with the fitting and it goes on to cover a portion of the pipe. won't this create a large "arcing area" as well?

Besides, proper bonding is the way to prevent arcing.
 
It is in the utility purveyor's prerogative to refuse connection per administrative guidelines despite compliance with the code. In my ahj, examples include:

a. The natural gas utility will not connect a meter to a home where copper tubing is used for gas supply lines or appliance connectors.

b. The water utility will not place a meter where an RPZ assembly is installed without a wye-strainer.

c. One out of our three electric companies will not accept combination service panels (breaker panel and meter loop combo) for homes having underground utilities.

d. A different one, out of our three electric companies will not set a new meter on a ring-type meter socket.

e. Our five sewer systems will accept cast iron private sewer lines. Only two of the five will accept PVC.
 
As far as the galvanized goes... For years, I have always been told that galvanized pipe/fitting systems were not allowed by code.

However, I don't see this in any of the codes since I became an inspector (2005). When was it not approved in the code to use galvanized?

The story I always heard was that the galvanization woud flake off and plug the pilot orifice. Was that just an old wives tale?

I always ran black pipe and fittings, with the exception of CSST.
 
Glennman CBO said:
As far as the galvanized goes... For years, I have always been told that galvanized pipe/fitting systems were not allowed by code.However, I don't see this in any of the codes since I became an inspector (2005). When was it not approved in the code to use galvanized?

The story I always heard was that the galvanization woud flake off and plug the pilot orifice. Was that just an old wives tale?

I always ran black pipe and fittings, with the exception of CSST.
Click to expand...
This changed a couple of code cycles back. I think the 2000 IRC.......
 
Hi TimNY, One additional requirement we have in my municipality is that if CSST is run perpendicular to the joists in an exposed location, such as an unfinished basement, than there has to be a backer board installed (1x4 or similar). We noticed that when the CSST was run between the joists it became a convenient place for homeowners to hang things.
 
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