Are New Gas Pipes Vulnerable to Lighting Strikes

Tim McElwain

NFPA is asking insurance underwriters to conduct a study:



Insurers will investigate whether corrugated stainless steel fuel-gas piping is liable to spring a leak if struck by lightning. The flexible piping, introduced in recent years and now found in about 1 million U.S. properties, has been blamed for several house fires. It is thought that additional grounding or bonding may offset the risk of lightning-induced gas leaks. <a href="http://r.smartbrief.com/resp/vongdojnmkAziOnwamaKyAalACPs?format=standard">[u][color=#660000]National Underwriter[/color][/u]</a> (free registration)<span style="color:#666666"> (4/5) </span><img src="http://www.smartbrief.com/images/briefs2/common/sm_share.gif" width="34" height="14" alt="Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the Internet." /><img src="http://www.smartbrief.com/images/shim.gif" width="4" height="4" alt="Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the Internet." /><a href="http://r.smartbrief.com/resp/vongdojnmkAziTfgamaKyAalHBgA"><img src="http://www.smartbrief.com/images/briefs2/common/linkedin.gif" width="14" height="14" alt="Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the Internet.

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D107

If I may add a corollary question....

Hi Tim, HO here. Question is do gas meters/valves installed outside increase vulnerability to lightning strikes, whether piping is corrugated stainless steel or black pipe.  Years ago most meters were installed inside the house in the basement in our area. (westchester ny). recently, when new lines are installed they put them outside--sometimes closer to the electric meter than code permits. (Electric meters also used to be installed indoors.)

Jean-David Beyer

Do you really mean "struck by lightning?"

My guess is that if you sustain a direct hit by lightning, the only protection is a good insurance policy. Now for near hits, my guess is that it will probably make little difference, though I would like to see scientific back-up for my guess.



The pipe the gas company put in for me last year is about three feet in the ground. That and the pipe in the street are plastic, so none of that does any good from a grounding standpoint. But the gas company seems OK with that. Where the pipe comes out of the ground to go through the regulator and the meter, it is all steel. From the meter part way into the garage (where my boiler is) is black pipe. Then some yellow flex across to the boiler area. Black pipe there until it disappears into the boiler. My ohmmeter reads 0 ohms between the gas pipe and the water feed pipe to the boiler.



 As far as I can tell, then, the flex is grounded at both ends. So this could take care of some near-misses, but how near? On the other hand, the grounds are about 15 feet apart, so large ground currents could induce considerable ground-loop currents in all the piping. Whether that is worse in flex pipe than in black, I am not sure.

Tim McElwain

David to answer

your question putting a meter outside or inside does not affect it getting struck. In all my years in the gas company I have never seen a meter get struck by lightning.



I have seen piping (black  pipe) on a roof top get a hole blown in it and catch on fire from a lightning strike. I have also seen copper tubing get zapped in customers homes.



The CSST (corrugated stainless steel tubing) has recently had some issues with supposed lightning strikes. That then caused an issue as to bonding the tubing and how and who was responsible for doing the bonding.



The National Fuel Gas Code used to require bonding of gas lines to a rod in the ground. That was later changed and as long as the gas equipment was connected to a 120 volt three wire grounded system bonding was no longer required.

hot_rod

pretty tough

to protect against lightning strikes. I had an old oak tree take a direct hit last year in my yard. The force split the tree down the middle and I found shards of wood several hundred feet away.



How far do you go to protect from such an arbitrary occurance? Lightning protection installers tell me no gauge of wire is guaranteed to protect a home or barn. Most are wired to ground stakes with large diameter, 1/2- 3/4" braided copper wire.



No warranty written or implied the people that install these systems tell me.



I wonder about all the seismic elements required in new construction. In Utah all homes required a "moment frame" of red iron. How much steel is enough for how much earthquake.



hr

TonyS

Gas connectors

We have been using them for years, the old ones were brass with plastic coating and the newer ones are stainless. They are the same thing as csst and we never had to ground them.

Mark Eatherton

The AHJ's here in Colorado.

REQUIRE bonding jumpers between any CSST flex connectors and black iron pipe.



From what I've heard, a lightning strike turns the CSST into swiss cheese. Like everyone else is saying, I am not sure what the benefits of having a jumper bond would be, but I'd sure hate to find out the hard way...



Better safe than sorry, and besides, I am not paying for it. The customer is.



ME

kcopp

that seems to be....

what most all code authorities are trying to do.... protect everyone from everything at all times even from their own stupidity.  kpc

Constantin

It's not just a grounding question...

... rather one of the path that the lightning takes once it gets into a home. The cases I have seen (here on the wall) of CSST getting punctured could just as well have been from nails, nicked 220V lines, etc. for all I know. Only an analysis of the puncture areas under a microscope would tell the story for sure.



What I think the underwriters are now trying to address is whether an external lightning/grounding conductor should be required with every CSST install. These conductors tend to be rather thick-gaged wire with few strands for a given nominal wire OD (at least compared to regular flexible wire). It would require more work (i.e. additional fittings) and would hence detract somewhat from the benefits of CSST (of which, fast installs, is one aspect being touted).



The benefit of black pipe is that it's pretty thick stuff. As such, it will be better able to absorb the high powered (and very temporary) arc that lightning generates than a thin-walled CSST pipe section. In a properly grounded home, the gas piping will be tied into all plumbing, electrical, etc. grounds. In our home, the external lightning protection is also tied into all pipes sticking out of the home (gas, oil, water).



Additional failure modes (besides lightning getting into the home itself) could be external piping going to things like gas lamps, outdoor kitchens, etc. Even if your home has lightning protection, not all external components may be covered by the cone of protection. Ditto for some external power connections - they can bring lightning into your home also.



Lastly, there is induced current, a phenomenon whereby a direct hit traveling down an external leader will induce a tremendous induced current in any electrical wiring that is running nearby in a similar direction. That is why having whole-house protection at the breaker panel or lightning protection on the home is not necessarily good enough - electronics need to be protected separately.  Really nasty environments will feature metal-walled and -roofed shacks and Ufer foundations to keep the electromagnetics on the outside (i.e. faradays cage + grounding).

Charlie from wmass

This issue was big here in Massachusetts

It ended up with CSST being removed from our market until it was addressed by the manufacturers. There is now a product called Counter Strike on the market and the bonding is now being strongly enforced. SInce gas installers be them plumbers or gas fitters are not licensed to do wiring in Mass we need to keep an electrician in the wings for running CSST. Or you can do what I do run black iron pipe. Out towards the ocean they had houses where lightening strikes turned the CSST to swiss cheese.

Gordy

Studies

 Tim, seems to me the studies should not only cover CSST piping, but black pipe as well. While they have found the CSST piping to be responsible for several house fires, have they looked into the fact that black piping could have been responsible in other cases as well.



Pretty hard to fully insure your house will not be damaged to some degree by a direct lightning strike bonded or not.  All though the gas pipe being damaged is the worst.



 Something tells me there is a direct correlation of odds being struck with the millions of homes that litter the landscape being ever increasing. Its harder for lightning to find an open area to strike.



 Study should also reflect whether or not houses that had issues with the csst piping were properly bonded electrically.  Were they new homes that fall into the latest codes for being bonded, or older homes that used csst in appliance hook ups off of black pipe that may have not been properly bonded electrically by code to begin with.



 You stated yourself that in all your years with the gas company you never witnessed this problem with black pipe. Obviously it was the fact that the black pipe never had completely failed, but could it be that black pipe may have had some damage but not enough to cause failure, or reason to be inspected there fore went unnoticed.



 Next has it been proved that bonding will actually help? Or is bonding just an idealistic band aid that everyone uses to prevent lightning damage in other areas hoping that this will prevent damage to csst.



 Gordy

Tim McElwain

Gordo If you look at my post

above I did state that I had a black pipe to a roof top gas heating unit get struck by lightning and it blew a hole in the 2" black pipe and it was on fire. So my theory is that lightning which can be upwards of 100,000 volts can damage any pipe. I have also seen copper lines on roof tops which had been struck and they were leaking water and have a definite hole in them.



By the way the size of wire required for bonding is a # 6 or larger to a bonding rod driven into the ground.

Gordy

Sorry Tim

I missed that.  What I'm wondering is this. Is bonding a way to keep a possibly inferior product (csst) in service.





 Were those instances you came across bonded, or bonded properly ?



Found an interesting read for the topic.

Mike Kusiak_2

Current carrying capability

Although any type of piping will be susceptible to damage from a direct lightning hit, it seems that the csst may be more easily damaged from less severe discharges. This is because of the the thinner gauge of the corrugated tubing and higher resistivity of stainless steel as compared to black iron pipe. The electrical resistance per given length will be much higher than for black pipe of the same size, which will cause greater heating with the same amperage discharge.



If both types of pipe are subjected to the same amperage current discharge, the csst will become much hotter and possibly melt while the same size black pipe might only get slightly warm. Because a lightning discharge is of very high peak amperage and short duration, the thermal mass also plays a part since the low mass csst will heat almost instantly. The much heavier black iron will not have nearly as high a temperature rise.



Although bonding may help, I'm not sure how really effective a relatively thin bonding conductor would be in bypassing currents in the order of tens of thousands of amperes. If it was my house, I would still prefer good old black iron.

         

Charlie from wmass

Thanks for the explanation Mike

It is clear now when you explain it that way. I think the bonding is simply the best they can do given the time and money already invested in pouring this product onto the market. I am going to hazard a guess that the supply tubes we use are less effected because the bulk of the current is transfered through the iron pipe to ground as the currents path would not as likely be towards the appliance but away from it.

Tim McElwain

The truth

is that bonding of gas piping in the National Fuel Gas Code was more an issue of someone touching a pipe which had a charge on it and getting electrical shock.



I can tell you as a gas man touching gas piping and meters when turning on the gas more than once I got a jolt. We actually had one of our servicemen get hit with 600 volts. The 600 volt line was in a building next door being demolished and the 600 volt line had fallen across the gas service, this transmitted into the building next door and our serviceman got zapped.



From that day forward we tested every line before touching it, any line with any voltage required a call to the electric company.

Tim McElwain

Gordy thanks

for that study, I was looking for that to post here.



To answer your question the bonding of the gas lines here in RI was never really enforced. It was on the books but most inspectors did not even know it was code. We had one electrical inspector who was big on enforcing it in one community but it never caught on state wide. It was the responsibility of the piping installer not the gas company as it was after the meter.

Mike Kusiak_2

Grounding with plastic service lines?

Tim, are there any requirements for grounding of black iron gas piping, especially when connected to a plastic service?



Back in the old days, the gas service was made of iron pipe and solidly connected to a metallic main in the street. This provided a good ground for the in-house distribution piping. Now with plastic mains and service lines, the solid ground is gone and the in house piping may effectively be "floating" with respect to ground, except where connected to electrical or plumbing ground through appliances. I wonder how many cases of problems with csst are due to this plastic service which definitely would require a external grounding conductor?



I wonder if the statistics differentiate problems with csst as to whether connected to a plastic or metallic service?

Tim McElwain

Mike it was my companies

policy in the 80's and 90's to follow this as relates to grounding:



ELECTRICAL GROUNDING

 

An electrical ground connection to a gas service is considered to be a hazardous condition to be approached with caution. Conditions which may exist include:

 

a)    An electrical ground connection to the service on a non-insulated meter header. First, an electrical arc may occur if any piping is separated. Voltage differences on the two separated sections could be sufficient for serious injury if the serviceman was to grasp both sections at once. (Any arcing is reason enough to install a dielectric union on the header before leaving the job site.) This is providing the voltage is not in excess of 10 volts. If voltage is in excess of 10 volts notify dispatch supervisor. Do not complete your work on the piping. Dispatch supervisor will call Narragansett Electric. Below 10 volts install a dielectric union.

 

If it is an emergency and you must work on meter, piping etc., a jumper is available from dispatch or with a district supervisor to jump across the existing piping so that you may safely service.

 

Voltage over 10 volts will also require a code violation report to be submitted.

 

If there is any emergency and you can not secure the piping have dispatch call electricians at the plant.

 

b)    An electrical ground connection to the street side of an insulator at the meter. The hazard to the serviceman is almost identical to that of the separated sections of piping in "(a)". A similar hazard is awaiting the Construction & Maintenance worker who contacts the pipe in the ground, since the service piping may not discharge all ground fault current transferred by the electrical connection.

 

The Company prohibits electrical connections to the gas service piping by either electrical or telephone systems. Grounding to the outlet piping commonly occurs through connections and contacts with house piping and appliances. We accept the National Fuel Gas Code (NFPA 54/ANSI Z223.1) recommendation that reads:

 

3.14 Electrical Bonding and Grounding.

 

a. Each above ground portion of a gas piping system upstream from the equipment shutoff valve shall be electrically con­tinuous and bonded to any grounding electrode, as defined by the National Electrical Code, ANSI/NFPA No. 70. This is to protect service personnel from electrical shock when servicing equipment.

 

b. Gas piping shall not be used as a grounding electrode.

 

3.15 Electrical Circuits.

 

Electrical circuits shall not utilize gas piping or components except that low-voltage (50 volts or less) control circuits ignition circuits and electronic flame detection device circuits may make use of piping or components for a part of an electric circuit.

 

If a serviceman encounters a ground wire connection on the gas service piping, do not remove the connection, as the Company would have to assume responsibility for any injury or damage as a result of the grounding condition change. Instead, advise the customer of the situation and that it should be corrected. Submit a Code Violation Report in accordance with Section 3.14 of the National Fuel Gas Code, ANSI Z223. 1 (1984).





That was policy until the late 90's when the code stated that if the appliance was properly grounded no bonding was necessary. It remains that way today with the latest code.





It is my feeling and also my experience that lightning does not distinguish between piping materials.



I do not know if any of the incidents were with plastic or black pipe. 

CMadatMe

Hasn't the Class Action

action suit already set precedence concerning this subject. The CSST mfgs peanut counters figured it was cheapier to settle vs fighting the suit. With that said every opinion is that just an opinion.

hot_rod

what about copper tube

used in gas and LP installations? Type M is allowed in some codes I believe. Any "swiss cheese syndrome" reported there? Certainly those "lawn sauage" LP tanks are a good lightning rod.



Gas flexes have been used for years before CSST came along. Gas flex are suggested for seismic areas to allow some movement before fittings brake. I don't recall lightning being an issue before CSST came along??



We had a cow struck and killed by lightning a few years back. Maybe I need to think about a bovine grounding system



hr

Unknown

Hey hr,,,

Have your cows wear plastic shoes LOL,,, (until someone finds something wrong with that type of plastic):-)

Jean-David Beyer

Plastic shoes for cows.

I know you were kidding (in more ways than one), but consider:



I do not know how well that would work for cows, but about 25 years ago I read about a guy who was climbing Mt. Blanc and got caught in a thunderstorm. He was hit by lightning but survived. I do not remember where he was hit (the head, I suppose) and the lightning came out his foot. (Or maybe it went the other direction.) In any case, he was wearing heavy leather mountain climbing boots and one of the boots was shown in a photograph. It was totally blasted out near the toes.



So plastic boots would not be enough.

Wikipedia has a pretty interesting article on lightning discharges.



http://en.wikipedia.org/wiki/Lightning

Gordan

The good news is that the bovine could be grounded after the fact

You just need to figure out what to do with all the hamburger.

Henry

National Gas code view

We discussed this and that study in commitee meetings.We also had a study of where most of the strikes were located: Southern and Midwest US. It is usualy the same locations that you have bad weather.

New and renovated houses typicaly now have only plastic piping: abs drains and Pex water. There is no steel anymore in those houses. The only steel is the gas pipe! It becomes a magnet for any lightning strikes! The problem is not the pipe.

Gordy

Lawyers

Face it fellas its about litigation more than anything. The NEC considers lightning protection systems beyond the scope of the NEC code, and direct or indirect lightning strikes beyond the means of man to prevent. Lightning protection systems do offer a level of protection......Its an effort.



Bonding of gas piping makes sense though if not for the very reasons, and experiences Tim has had.....Things can, and do happen. Its an effort to prevent something. If there is a means to help prevent something no matter how feeble you may think it is, or really is you better use it, or the lawyers will against you because you did not if something should happen. Its amazing how ignorance is no excuse for the defendant, but can be the excuse of the plaintiff.



As far as bonding anything to disipate a lightning strike to any mechanical system all bets are off in my mind as to the level of protection. But it is a level of protection, and an effort so, you better use it.



Gordy



Gordy