Conductive Metal Gas Piping Bonding (OTHER THAN CSST)

[CuriousHomeInspector]

I see lots of posts here on CSST, but I have a question regarding non-CSST metallic gas piping.

I often see home inspectors claim that in a system that has a furnace or other appliance connected to fuel gas distribution piping, there has to be an obvious visible bonding jumper etc installed.

My rub with this is that International Fuel Gas Code 310.1 SPECIFICALLY states that if the piping is connected to the appliance no additional bonding is needed.

HOWEVER. "piping" is a defined term in the IFGC. My argument is that the flexible connectors often seen are NOT considered "piping" in the IFGC, rather they are considered an appliance connector.

In my opinion for the bonding to be continuous throughout the gas piping system, the connectors should be jumpered around.

Am I crazy?

 

[petersonra]

I see lots of posts here on CSST, but I have a question regarding non-CSST metallic gas piping.

I often see home inspectors claim that in a system that has a furnace or other appliance connected to fuel gas distribution piping, there has to be an obvious visible bonding jumper etc installed.

My rub with this is that International Fuel Gas Code 310.1 SPECIFICALLY states that if the piping is connected to the appliance no additional bonding is needed.

HOWEVER. "piping" is a defined term in the IFGC. My argument is that the flexible connectors often seen are NOT considered "piping" in the IFGC, rather they are considered an appliance connector.

In my opinion for the bonding to be continuous throughout the gas piping system, the connectors should be jumpered around.

Am I crazy?

where does the code require continuous bonding?

 

[CuriousHomeInspector]

IFGC (2015, 2018, and others) 310.1

"Each above ground portion of a gas piping system other than corrugated stainless steel tubing (CSST) that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping other than CSST shall be considered to be bonded where it is connected to appliances that are connected to the equipment grounding conductor of the circuit supplying that appliance."

Does the appliance connector (different than piping) still count as making the piping electrically continuous?

More specifically, the appliance connector may not meet the requirements of 250.104(B) as part of that electrically continuous path, as it is an appliance connector and not piping. I don't see how that connector meets the requirements of 250.104(B) or 250.8

 

[petersonra]

that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path.

There are two key issues. One is "likely to be energized" and the other is "effective ground-fault current path".

Generally, the gas piping is not considered likely to be energized except by an appliance that is connected to it that is supplied by an electrical source. Such a source is already required to have an equipment grounding conductor that provides an effective ground fault path, so no additional bonding is required. The metal frame of the appliance is also an effective ground fault path so anything connected to it electrically such as a gas line is effectively bonded.

You seem to be trying to enforce a rule that does not actually exist.

 

[CuriousHomeInspector]

I'm not trying to enforce a rule that does not exist. I'm trying to clarify a rule the most definitely does exist. Metal piping that is connected to appliances such as furnaces are required to be bonded to an appropriate ground-fault current path (example: for appliances such as gas logs which have no electrical source etc, this bonding is not required).

The international fuel gas code DOES require bonding of metal piping systems when connected to a furnace etc. What I'm trying to figure out is what connection(s) are appropriate and if an appliance connector is considered to make the metal piping system continuous (as it is an appliance connector, not piping).

 

[CuriousHomeInspector]

I believe "likely to become energized" has been widely debated, and some even consider it among one of the worst phrases of the NEC. For the purpose of this argument lets assume that "likely to become energized" to the AHJ means a gas fuel burning appliance is connected to the main power source of the home (blower motor is present etc).

 

[jaggedben]

In my opinion... generally speaking...

If the main trunk gas pipe coming into the house is bonded, and if any appliances that are both gas and electric connected have proper EGCs, and the only places where the gas piping is not electrically continuous is at flexible connectors to appliances, then most likely due diligence has been done and the code requirements have been met.

 

[CuriousHomeInspector]

In my opinion... generally speaking...

If the main trunk gas pipe coming into the house is bonded, and if any appliances that are both gas and electric connected have proper EGCs, and the only places where the gas piping is not electrically continuous is at flexible connectors to appliances, then most likely due diligence has been done and the code requirements have been met.

I agree whole-heartedly with this. However in some states (looking at you Arkansas) many jurisdictions don't ask for the main gas pipe coming into the house to be bonded. And often times when they do they take it down to a ground rod that is not connected back to the electrical service ground (the soil does not count as a connector between multiple ground rods, no?), or it is just a buried wire connected to nothing (not talking about the locator wire on the service side of the meter either).

I do know of at least one jurisdiction that basically took the stance of requiring bonding at the entrance near the meter on the house side and that takes care of things as you stated.

 

[petersonra]

I'm not trying to enforce a rule that does not exist. I'm trying to clarify a rule the most definitely does exist. Metal piping that is connected to appliances such as furnaces are required to be bonded to an appropriate ground-fault current path (example: for appliances such as gas logs which have no electrical source etc, this bonding is not required).

The international fuel gas code DOES require bonding of metal piping systems when connected to a furnace etc. What I'm trying to figure out is what connection(s) are appropriate and if an appliance connector is considered to make the metal piping system continuous (as it is an appliance connector, not piping).

What is connected to the appliance? There just is no requirement for bonding of piping systems that are not likely to become energized. If the piping is connected directly to the appliance it is bonded by that connection. if it is connected to a flexible piece of gas tubing it is not likely to become energized by the appliance anyway.

 

[infinity]

What is connected to the appliance? There just is no requirement for bonding of piping systems that are not likely to become energized. If the piping is connected directly to the appliance it is bonded by that connection. if it is connected to a flexible piece of gas tubing it is not likely to become energized by the appliance anyway.

I agree. The EGC for the appliance is all that the NEC requires for bonding black gas pipe.

 

[hbiss]

I think he's asking if the flexible gas connector that is sometimes installed between the water heater, dryer, range, boiler or furnace and the black iron gas line is suitable for maintaining an electrical bond between the gas line and appliance.

Answer is yes. All are made out of corrugated stainless steel which is certainly a conductor.

-Hal

 

[PaulMmn]

I think he's asking if the flexible gas connector that is sometimes installed between the water heater, dryer, range, boiler or furnace and the black iron gas line is suitable for maintaining an electrical bond between the gas line and appliance.

Answer is yes. All are made out of corrugated stainless steel which is certainly a conductor.

-Hal

Is it considered like the spiral wrap on BX cable-- it's not a ground conductor unless it has the shorting wire inside?

(Yes, I know it's gas, and the 'shorting wire' will have to be outside)

 

[infinity]

I think he's asking if the flexible gas connector that is sometimes installed between the water heater, dryer, range, boiler or furnace and the black iron gas line is suitable for maintaining an electrical bond between the gas line and appliance.

Answer is yes. All are made out of corrugated stainless steel which is certainly a conductor.

-Hal

If the flex is not a conductor then the appliance cannot energize the gas pipe, if it is a conductor then it will bond the gas pipe. Either way nothing more is required by the NEC.

 

[petersonra]

I think he's asking if the flexible gas connector that is sometimes installed between the water heater, dryer, range, boiler or furnace and the black iron gas line is suitable for maintaining an electrical bond between the gas line and appliance.

Answer is yes. All are made out of corrugated stainless steel which is certainly a conductor.

-Hal

I don't know if that is true or not, but there just is not a requirement to bond the gas line unless it is likely to become energized and I don't see how the pipe can become energized.

 

[kwired]

Is it considered like the spiral wrap on BX cable-- it's not a ground conductor unless it has the shorting wire inside?

(Yes, I know it's gas, and the 'shorting wire' will have to be outside)

It is not spirally wrapped like BX cable, if it were it would not contain the gas very well at all as there would also be a continuous spiral seam that is not sealed. It is solid but corrugated tubing and has less resistance per length unit than if it were spiraled.

 

[Another C10]

I see lots of posts here on CSST, but I have a question regarding non-CSST metallic gas piping.

I often see home inspectors claim that in a system that has a furnace or other appliance connected to fuel gas distribution piping, there has to be an obvious visible bonding jumper etc installed.

My rub with this is that International Fuel Gas Code 310.1 SPECIFICALLY states that if the piping is connected to the appliance no additional bonding is needed.

HOWEVER. "piping" is a defined term in the IFGC. My argument is that the flexible connectors often seen are NOT considered "piping" in the IFGC, rather they are considered an appliance connector.

In my opinion for the bonding to be continuous throughout the gas piping system, the connectors should be jumpered around.

Am I crazy?

I did a panel upgrade last week and 9 out of 10 times I Ace the Inspection, this time I got written up on 2.
1) Remove bond from gas .. His argument was that the bond was redundant because gas appliances are plugged in and the circuit ground is sufficient. So I gave him Article 250-104 (B) (3) He still said no remove it .. My theory is accidents happen who's to say that a gas line in the attic may never see a fault current. I've always bonded at the load side of the Gas Meter

2) He provided Article 250.94 Intersystem lug at data utility ... ok whatever.. I did it, but it was all existing so I figured bonding it to the ufer ground was better than the meter housing clip they wedge on the panel after the fact. Before doing that I threw back Article 770.100 (B2) 1.

He denied both article arguments so I just altered it to the inspectors choice. Codes are great but they are sure contradictory at times.

 

[infinity]

I did a panel upgrade last week and 9 out of 10 times I Ace the Inspection, this time I got written up on 2.
1) Remove bond from gas .. His argument was that the bond was redundant because gas appliances are plugged in and the circuit ground is sufficient. So I gave him Article 250-104 (B) (3) He still said no remove it .. My theory is accidents happen who's to say that a gas line in the attic may never see a fault current. I've always bonded at the load side of the Gas Meter

Although not required I don't see how anyone can tell you to remove an additional bonding conductor. You've exceeded the NEC which is the minimum requirement for installations. If the bonding every piece of metal in the entire building makes you all warm and fuzzy there is no hazard in doing so.

 

[kwired]

Is it considered like the spiral wrap on BX cable-- it's not a ground conductor unless it has the shorting wire inside?

(Yes, I know it's gas, and the 'shorting wire' will have to be outside)

But it is not "spiral" like FMC is, that wouldn't keep the gas inside very well, it is a solid but corrugated tube.

Oops, I see this is older thread and I already said about the same thing earlier.

 

[Another C10]

Although not required I don't see how anyone can tell you to remove an additional bonding conductor. You've exceeded the NEC which is the minimum requirement for installations. If the bonding every piece of metal in the entire building makes you all warm and fuzzy there is no hazard in doing so.

Thank you, I didn't think I was completely wrong, I usually incorporate a standard based on the toughest inspectors I've had to deal with just so as to not get any surprises in other smaller cities. I think it's better to bond at the gas utility just as a safety valve for potential faults unless its an all plastic system which newer homes seem to gravitate towards. Thanks again.