Pipeline weights

[larryli2004]

Does anybody have the software for pipeline weight calculation? I have a 6" insulated pipeline. Pipeline may cross some muskeg area. I want to check whether the weight is required.

 

[BigInch]

6" pipe is borderline for weights, 6" lighter walls need weights, however the heavier walls don't. With insulation, plan on using weights.

Have you tried screw anchors??? I have a lot of pipeline held down with those up in the Land of 10,000 Lakes. And even some screw anchors making "H" supports underwater in a bay in Tx. Screw anchors work well and are cost effective when compared against handling & installing all that concrete.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[pennpiper]

Go here:

http://www.pipingdesigners.com/Tools.htm

Then in the second category "calculators"
Click on:
"Imperial Weight Book"
or
"Metric Weight Book "
depending on what units you are working in.
They are useful tools and easy to use.

 

[larryli2004]

Thank you. I got one later. If it is muskeg area, 6" with insulation will require weight. However I will get a test report for muskeg area. If the muskeg is shallow, we might be ok.

 

[BigInch]

What difference does it make if its shallow? Water always finds a way in.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[daviwy]

You can work out the pipe weight if you have the details of the pipe

you need

Pipe material (to get the pipe density)

Pipe outter diameter and internal diameter (to work out volume)
volume = surface area x length

the weight of the pipe will be = volume x diameter

then you need the details of the insulation material and insulation thickness to work out the weight of the insulation

add the two together and you will get the overall weight

if you have any other questions drop me a line.

 

[zdas04]

daviwy,
He is looking for required additional weights to keep a pipeline from floating, not the weight of the pipe.

I always address this problem by determining the weight of displaced water. So, 1 ft of 6-inch pipe with 2-inches of insulation has a total volume of 0.6 ft^3. Assuming fresh water then you are displacing 38 lbm of water. 6-inch standard wall pipe weighs 18.97 lbm/ft, so if you ignore the weight of the insulation and any product in the line you are buoyant by 19 lbm/ft. With that kind of buoyancy I'd look into Big Inch's screw anchors.

David

 

[larryli2004]

David, you are right. I already got the test report and the muskeg is preety bad (3-4 meter deep). I already calculated the weight required (10" weight) and the spacing.

 

[BigInch]

What is a 10" weight?

He's probably displacing something considerably more heavy than water. What's the density of the muck? That's what you need to use when calculating the buoyant force, then add enough weight to get a safety factor of around 1.25 to ensure it doesn't lift up anywhere.

So if you're up there in Canada and you bury it 1 m clear, how do you keep the pipe from sinking to the bottom of the 4m when you put the weights on it?

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[racookpe1978]

Canada = Summertime melt = down how far in that particular swamp/muskedge area/bog will it be melted?

How does he support it across the permafrost (down to the permafrost?) as that layer moved up and down?

 

[BigInch]

Is that another name for permafrost (always frozen)? I think its more like a bog that does freeze and thaw. Then again, even a lot of permafrost is thawing in the hotter summers these days.

Several options;

Actually it could be best to avoid wet areas entirely.

Plus its possible that the gas/oil is hotter than 0ºC and will keep any water melted, so maybe it has to be chilled so its kept frozen, which also avoids ice lensing effects.

Or constructed above ground on supports with heat dissapation fins, so the soil below isn't thawed from the heat (as per TAPS method).

Or buried at 4m depth using weights.

Or bury at higher elevation and provide enough flexibility that it can sink later without overstressing.

Or held at a particular elevation with extensions to screw anchors where the screws are actually embedded well below the 4 m depth.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[daviwy]

Thanks for the correction,

to my knowledge you have means of burying the pipeline underwater. use of a shroud / protective layer on the pipeline and then using the appropriate method to bury this pipeline below the sea?

maybe under the sea bed (muskeg) and then rock dumping around the pipe?

to do this you have to consider a few factors though:

. Environmental permit to do so

. How you can dump not to impact the integrity of the pipe?

. Basic logistics, i.e. where to get what from and how and how much?

 

[BigInch]

Excavation of a trench in bogs can be somewhat difficult at such depths since the sides will probably tend to collapse and make for excavation of a very wide trench. Hauling rock around on top of it also not great. With that depth even extrawide mud wheels can get stuck so mud mats would be required for roadway and neither do much for the flowers and fauna under them either. Haulage must be kept to an absolute minimum.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/