Bonding Flexible Gas Lines

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Ravenvalor

Ravenvalor

Senior Member
Location
Piedmont region of NC
Hello,

My apologies in advance for not putting this question in the "Grounding vs Bonding" forum.
My customer wants me to bond some flexible gas lines underneath his house. I intend to check with the manufacturer on the correct way to make these bonds. The sub panels are in the basement about a 25 to 50 feet run to the gas lines. The service panels are in the garage about a 125 to 150 feet run to the gas lines. If I need to bond the gas lines to the service, is 125 feet a little long to divert a lightning strike?

Thank you,
 
Chances are your gas lines are already bonded. Your circuit to the fan has an equipment ground in it. This creates a bond.

How ever csst gas lines did have some pin holes occur due to lightning. The manufactor has said a bigger bonding conductor is required.
You would put a ground clamp on a coupling.

A #4 on a 200 amp service would be good back to the main. How ever some will say bonding back to the sub is compliant.
 
Bonding Flexible Gas Lines

Buck Parrish said:
Chances are your gas lines are already bonded. Your circuit to the fan has an equipment ground in it. This creates a bond.

How ever csst gas lines did have some pin holes occur due to lightning. The manufactor has said a bigger bonding conductor is required.
You would put a ground clamp on a coupling.

A #4 on a 200 amp service would be good back to the main. How ever some will say bonding back to the sub is compliant.
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125 feet seems like a long distance to divert a lightning strike.
 
FWIW I only know of one single CSST manufacturer that requires the bond be sized per 250.66,,,I think that manufacturer is Wardflex if I remember correctly.

All other manufacturers allow a # 6 bond
 
Bonding of the CSST lines is not meant to disperse a direct hit to the lines.
Its intention is keep the lines at the same potential so there is not arcing between potentials. Everything rises and falls at the same time.

There are one or two manufacturers that now include a bonding strip in the CSST. I wonder where they got that idea from.:roll:
 
Ravenvalor said:
I will try to find this type gas line thanks.
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The manfacturer's name is usually on the piping. There was at least one manufacturer, as MCClary stated, that does requires using 250.66. I always just use that table and I know I will have no issues.

You must go to the main service regardless of the distance. Are you sure there is no hard pipe that comes out near the service. Most piping around here exits the structure near the service so bonding is quite simple.

Remember you can bond to the hard black iron piping if there is any in the system. Don't bond the CSST (corrugated stainless steel tubing) on the tubing but on the connector-
 
gas line

gas line

Dennis Alwon said:
The manfacturer's name is usually on the piping. There was at least one manufacturer, as MCClary stated, that does requires using 250.66. I always just use that table and I know I will have no issues.

You must go to the main service regardless of the distance. Are you sure there is no hard pipe that comes out near the service. Most piping around here exits the structure near the service so bonding is quite simple.

Remember you can bond to the hard black iron piping if there is any in the system. Don't bond the CSST (corrugated stainless steel tubing) on the tubing but on the connector-
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Good info, thanks.
There is rigid piping in between the gas service and the csst. I will check with the manufacturer about bonding directly to it. Also I might insist that the customer use csst with bonding strip.
Thank you again.
 
Ravenvalor said:
Good info, thanks.
There is rigid piping in between the gas service and the csst. I will check with the manufacturer about bonding directly to it. Also I might insist that the customer use csst with bonding strip.
Thank you again.
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It might be better to tell him why there is even an issue in the first place. He may think about using hard pipe only. Kaboom!

Whatever the case, you don't have to bond each gas line if there are more than one run. There has to be a manifold somewhere that they all connect to. That is an ideal place to bond.
 
Ravenvalor said:
Good info, thanks.
There is rigid piping in between the gas service and the csst. I will check with the manufacturer about bonding directly to it. Also I might insist that the customer use csst with bonding strip.
Thank you again.
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You don't have to call the manufacturer -- I give you my blessings. Seriously, I have talked to the mfg. and they say anywhere on the line is fine-- hard pipe or wherever is easiest.

They do make CSST that does not need bonding. I know omegaflex makes "counterstrike" where no additional bonding is necessary other than what 250.104(B) calls for.
 
electricmanscott said:
Whatever the case, you don't have to bond each gas line if there are more than one run. There has to be a manifold somewhere that they all connect to. That is an ideal place to bond.
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Isn't it true, though, that if there's CSST between the gas service and that manifold, it's not the right place to bond?
 
You don't have to run the bonding jumper to the service. You can bond it to the grounding electrode which can be either structural metal or a water pipe. The bonding jumper should be sized according to NEC 250.122 using the rating of the circuit that is likely to energize it.
 
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erickench said:
The bonding jumper should be sized according to NEC 250.122 using the rating of the circuit that is likely to energize it.
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I disagree. The bonding jumper must be either 250.66 or if the mfg states so a #6 copper conductor. The egc will not suffice for flexible gas line (CSST)
 
Dennis Alwon said:
I disagree. The bonding jumper must be either 250.66 or if the mfg states so a #6 copper conductor. The egc will not suffice for flexible gas line (CSST)
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NEC 250.104(B) give's the rules for bonding gas piping. No mention is made here about flexible or rigid. The rule state's that NEC 250.122 is to be used.
 
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erickench said:
NEC 250.104(B) give's the rules for bonding gas piping. No mention is made here about flexible or rigid. The rule state's that NEC 250.122 is to be used.
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The NEC is only (one) of about 100 books that contribute to how structures are built nowadays. Dennis is correct in everything he said.

NEC does not concern itself with Manufacturer requirements of CSST, check out the USBC and see the difference
 
erickench said:
NEC 250.104(B) give's the rules for bonding gas piping. No mention is made here about flexible or rigid. The rule state's that NEC 250.122 is to be used.
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Eric, the mfg specs overrule the NEC. You cannot use 250.122. You can for black iron but not CSST.
 
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