What size pipe will you be served?

Safety is, of course, a big concern for those who will be potentially living near gigantic high-pressure natural gas pipelines like PennEast. But, as I’ve documented before , how safe the pipe will be for you depends on exactly where you live. Thanks to the “Class Location” system, if you live out in the beautiful country side with few neighbors, you’re going to get a pipe that’s less safe. If you live in a city you’ll get the strongest possible pipe.

My post above talks about many of the details of how Class Location works and the safety “features” it defines. But one of the things not mentioned there is exactly how thick the pipeline will be for those locations. Which is ashamed – having a hard number help many people understand these things better. So let’s get those hard numbers out there!

What The Thicknesses Are

Pipeline thickness varies depending on the quality of steel being used (in terms of what’s called the yield strength of the material , the envisioned maximum operating pressure, the diameter of the pipe, and the safety factor associated with your class location. Fortunately we know all of these values for PennEast:

Yield Strength 70,000 psi (X70 pipe)
Operating Pressure 1,480 psi
Pipe Diameter 36”

And the “design factor” based on class location is as follows:

Class 1

Class 2

Class 3

Class 4





What this means is that Class 1 locations have the pipeline operating at up to 72% of its safety margin.  Class 2 locations will operate at 60% of the safety margin.  Class 3 is at 50% of safety margins.  And Class 4 is at 40% of safety margin.

Now, as a practical matter you can’t vary the pressure of the pipeline, and you’re not going to generally vary the steel or diameter either, so what class location affects is the pipeline thickness.  The lower your class location, the smaller the thickness of the pipe.  Here’s the formula for figuring out what thickness should be used:

Thickness = (Max Pressure * Pipe Diameter) / (2 * Yield Strength * Design Factor)

Plugging in the numbers for PennEast, we have:

Thickness = (1480 psi * 36″) / (2 * 70000 * Design Factor)

And finally with this we can show the thickness based on Class Location:

Class 1

Class 2

Class 3

Class 4





As you can see, class location has a HUGE impact on thickness.  Class 1 pipe will be a hair over 1/2″ thick.  Class 2 pipe is almost 2/3″ thick.  Class 3 pipe is just over 3/4″ thick.  And Class 4 pipe is nearly 1″ thick.

How To Figure Out Your Class Location

You can find out your class location from the PennEast application maps.  If you go here:

…on the right side top of the page you’ll see a section entitled “Pipeline Mainline Maps (Appendix C). These are the construction maps for PennEast. It looks like this:

C2 – Mile Marker 0 to Mile marker 5
C3 – Mile Marker 5 to Mile marker 10
C4 – Mile Marker 10 to Mile marker 15
C5 – Mile Marker 15 to Mile marker 20
C6 – Mile Marker 20 to Mile marker 25
C7 – Mile Marker 25 to Mile marker 30
C8 – Mile Marker 30 to Mile marker 35
C9 – Mile Marker 35 to Mile marker 40
C10 – Mile Marker 40 to Mile marker 45
C11 – Mile Marker 45 to Mile marker 50
C12 – Mile Marker 50 to Mile marker 55
C13 – Mile Marker 55 to Mile marker 60
C14 – Mile Marker 60 to Mile marker 65
C15 – Mile Marker 65 to Mile marker 70
C16 – Mile Marker 70 to Mile marker 75
C17 – Mile Marker 75 to Mile marker 80
C18 – Mile Marker 80 to Mile marker 85
C19 – Mile Marker 85 to Mile marker 90
C20 – Mile Marker 90 to Mile marker 95
C21 – Mile Marker 95 to Mile marker 100
C22 – Mile Marker 100 to Mile marker 105
C23 – Mile Marker 105 to Mile Marker 110
C24 – Mile Marker 110 to Mile Marker 115

These are maps broken down by PennEast Mile Marker.  If you know your mile marker, go into the appropriate file, and you’ll find the construction maps for you site.  Here’s mine:


The top part of the map shows visually what’s going on.  Then there’s a bunch of lines below that.  Those lines are characteristics broken down by where they are on the map.  I’ve called out two of them – they are Class Location and Design Factor.  These are what PennEast consider to be the Class Location for that portion of the map, and the Design Factor as well.  They change the Design Factor in some cases separately from the Class Location.  In this example, I am listed as Class 1 (oh boy!) with an associated design factor of 0.72.  But a little sliver is shown wth a design factor of 0.6.  That sliver is Hewitt Road, they use slightly better pipe under roads.

So find your own map and you can find the class location and design factors for your area.

Don’t know your mile marker?  Email me your address at “thecostofthepipeline@gmail.com” and I’ll let you know.

Hey I Thought PennEast Wasn’t Using Class 1 Pipe?!?

So did I.  But the construction maps do have Class 1 all over the place.  More importantly, they specify a design factor in the construction maps, and those design factors match up with Class 1 ones.

PennEast should be called out for claiming they are using Class 2 as a minimum in all locations when their actual construction plans call for Class 1 in many sites.


Published by

Mike Spille

I'm a thinker, an analyzer, a synthesizer. Maybe not in that order. I live in West Amwell NJ with my wife Kristina, our two kids Day and Z, our two dogs Fern and Cinna, and three cats Ponce de Leon, Oliver, and Doolittle.

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