Natural Gas Distribution Maintenance

[MPdesign]

Gentleman,

I am looking for information on the proper maintenance, life, and refurbishment of natural gas piping and components including meters, valves, etc.

I am looking at a distribution system owned by a university so it will include many items including bad grounding issues.

Do any of you have any recommendations on where I can find this information?

[Jim Katen]

Gentleman,

I am looking for information on the proper maintenance, life, and refurbishment of natural gas piping and components including meters, valves, etc.

I am looking at a distribution system owned by a university so it will include many items including bad grounding issues.

Do any of you have any recommendations on where I can find this information?

I can't help you with the care & feeding of gas piping. However, you got my attention with your mention of "bad grounding issues."

Before you touch a "grounding" connection to a gas pipe, are you aware of the difference between bonding and various forms of grounding and how they relate to gas piping?

There's a whole army of ignorant HVAC techs out there who go around disconnecting "grounding" wires that they think are "bad".

- Jim Katen, Oregon

[MPdesign]

Yes, I am aware that I am ignorant. hehe

I am very aware of electrical grounding systems for buildings. I am very aware of bonding the grounding system on buildings to incoming water pipes as well as bonding to lightning protection systems, etc.

I am not aware of how this pertains to site distribution or natural gas in particular.

The reason that I mention that is because I am aware of *several* locations where the natural gas piping exits the ground for a 2 foot span and then goes back into the ground. These locations are connected to ground leads and ground rods (not a building grounding triangle - just out *open* on the site). I assume that these keep the potential difference between the pipe and the ground constant to stop any potential arcs. Most of these ground wires are cut from lawn cutting services. That is why I ask.

[MPdesign]

Gentleman,

I have found the doc (I think) that anyone would want to read/ reference on the subject of natural gas distribution on a site such as a campus where the owner maintains it all.

Link

[Charlie R]

"Most of these ground wires are cut from lawn cutting services. That is why I ask." Are you sure they are ground wires or are they locator wiring? If the gas piping underground is non-metallic, then they wrap a locator wire around it so you can locate the pipe underground with a metal detector. The wiring simply ends above ground but is not physically attached to the piping.

[MPdesign]

Very good info. Thank you!

I will check. I wondered why you needed to ground wire when 90% of the pipe was metal - and buried underground (i.e. already at ground potential).

I assume that if what you are saying is what I am seeing, then there will be no clamp to hold the wire to the pipe - and when I dig around a bit, there will be no rod.

Thanks again!

[MPdesign]

May also be cathodic protection (if cadwelded) to the piping!?!

[inspector57]

No, just a tracer wire. most modern underground gas pipe is plastic and needs the tracer wire. The riser will be metal but will transition to plastic.

Just for the record, gas piping is not "Grounded" anywhere but all metallic pipe likely to become energized should be "bonded" to eliminate voltage differences just like the bonding of pool equipment.

Grounding provides an intentional low impedance path in electrical circuits for electricity back to the source.

Bonding is there to protect against unintentional voltage that may be present on things that are not part of the electrical equipment.

I'm sure there are those here far more eloquent than I that can expound to correct and put a finer point on the subject.