Exposed galvanized gas line

[DIYorBust]

We're running a BBQ gas line in galvanized pipe. The entire run is above ground, not buried, and galvanized is allowed by the code in NYC for this purpose, but not for buried pipe.

Now my question is, should any additional steps be taken to prevent corrosion in the pipe? Would it benefit from being oiled up or milwrapped? Painting is not allowed in NYC for wacky reasons discussed before.

Thanks,

DIYoB

 

[John Gayewski]

You just need to make sure any threads that are exposed get a coating. Any metal that is exposed to the elements will get an accelerated deterioration. I would use "galvanized paint". It goes on like spray paint and looks like galvanized coating. Also coat both sides of the hangers your using to secure the pipe. Stainless screws

 

[Sponsor]

 

[DIYorBust]

Thanks, we have cold galvanizing compound from zrc, I think that is the stuff you're suggesting, we can use it to touch up the threads. So I guess it will hold up okay without any further protection?

 

[Sylvan]

We're running a BBQ gas line in galvanized pipe. The entire run is above ground, not buried, and galvanized is allowed by the code in NYC for this purpose, but not for buried pipe.

Now my question is, should any additional steps be taken to prevent corrosion in the pipe? Would it benefit from being oiled up or milwrapped? Painting is not allowed in NYC for wacky reasons discussed before.

Thanks,

DIYoB

I have no idea who lied about NYC not allowing painting of gas lines?

There is no more Millwrapped pipe in plumbing supply houses and now the wrapping is performed by the installer

We used to use coal tar enamel with 15# felt hot applied

I heard a liar state "Galvanized gas piping is not allowed in NYC".

Obviously they spew nonsense with no idea what a code is

Gas piping CAN BE painted in doors as well as outside

The only problem is painted old gas lines must be tested @90 PSI instead of the 3 PSI test

All my employees have taken and passed the required certifications


https://www1.nyc.gov/assets/buildings/pdf/gas_works_sn.pdf

 

[DIYorBust]

Thanks Sylvan, I understand that gas line can be painted if it's tested at 90 psi, we have discussed that here before. But why would we want to do that, it's not a high pressure gas line and if we're tying into older sections it might not pass. Also other rules apply to high pressure lines besides just the test pressure.

I've heard much confusion about the Galvanized in NYC issue. Maybe the new code will clarify that. One area where it is specifically mentioned in the 2014 fuel gas code is that outdoors and above ground, it can be used and will be considered adequate protection for the pipe. It's not clear to me if it can be used indoors. If it could, I would probably specify it as rusty pipes can cause an LL152 failure now.

 

[Sylvan]

Thanks Sylvan, I understand that gas line can be painted if it's tested at 90 psi, we have discussed that here before. But why would we want to do that, it's not a high pressure gas line and if we're tying into older sections it might not pass. Also other rules apply to high pressure lines besides just the test pressure.

I've heard much confusion about the Galvanized in NYC issue. Maybe the new code will clarify that. One area where it is specifically mentioned in the 2014 fuel gas code is that outdoors and above ground, it can be used and will be considered adequate protection for the pipe. It's not clear to me if it can be used indoors. If it could, I would probably specify it as rusty pipes can cause an LL152 failure now.

On this co op I installed a 3" gas line reduced to 21/2 and then 2" and ran it from the sub basement through the garage and then outside to the two pool heaters

https://streeteasy.com/building/river-point-towers

Con Ed refused to turn on the gas as Galvanized was used after explaining the NYC plumbing code as well as the AGA and NFPA and requesting another "qualified" inspector the gas was authorized and turned on

The reason Galvanized was against the code was simple.

The powers that be thought the Zinc coating would peel off exposing a sand hole and causing a leak, another theory was the Zinc would flake and block the office of appliances such as boilers, stoves, water heaters etc.


Here is an old picture installing the 3" gas line in a boiler room and doing minor service call on an old boiler we installed and newly installed gas piping that I am inspecting






https://streeteasy.com/building/river-point-towers

 

[wwhitney]

another theory was the Zinc would flake and block the office of appliances such as boilers, stoves, water heaters etc.

The version of this theory I heard is that formerly natural gas had a higher sulfur content, and the zinc would corrode to zinc sulfide, which would flake off.

Cheers, Wayne

 

[John Gayewski]

Just fyi we never use galvanized pipe for gas. Painted black pipe is plenty fine. If it penetrates a wall it has to be wrapped in an approved gas line wrap. Which is basically extra wide electrical tape.

 

[DIYorBust]

The nyc fuel gas code the below about galvanized gas pipe that it is adequate protection for an exposed location, and in fact is the only enumerated protection method. As painting is not allowed on a low pressure line, it may actually be the only practical method other than mil wrap, or sleeving.

404.9 Protection Against Corrosion

Metallic pipe exposed to corrosive action, such as soil condition or moisture, shall be protected in an approved manner. Zinc coatings (galvanizing) shall not be deemed adequate protection for gas piping underground. Ferrous metal exposed in exterior locations shall be protected from corrosion. Zinc coatings (galvanizing) shall be deemed adequate protection for gas piping exposed in exterior locations. Where dissimilar metals are joined underground, an insulating coupling or fitting shall be used. Piping shall not be laid in contact with cinders.

 

[Sylvan]

NYC 1968 plumbing code

" All piping passing though a foundation wall shall be protected by arch, lintel or IPS Sleeve"

 

[DIYorBust]

NYC 1968 plumbing code

" All piping passing though a foundation wall shall be protected by arch, lintel or IPS Sleeve"

Yes we got that.