University of Arizona professor invents lightweight infinite pipeline


August 21, 2012

The InfinitiPipe can be manufactured on site (Image: University of Arizona)

The InfinitiPipe can be manufactured on site (Image: University of Arizona)

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A University of Arizona professor has invented a theoretically infinite pipe that promises to bring down the costs of laying pipelines while reducing environmental damage. Developed by Mo Ehsani, Professor Emeritus of Civil Engineering at the University of Arizona, the new pipe, called InfinitiPipe, is of a lightweight plastic aerospace honeycomb under layers of resin-saturated carbon fiber fabric put together by a new fabricating process that allows pipes to be built in indefinite lengths on site.

Because they’re out of sight, we sometimes forget how much pipe lies buried under our feet. Spreading throughout and between towns and cities there are thousands, if not millions of miles of pipeline carrying fuel, water, sewage, cables and all manner of other things that make up the veins and arteries of modern civilization. The problem is that any large pipe intended to have any strength, such as those made out steel, concrete or heavy plastic, can only be made in very short lengths. This is partly due to the weight of some materials, but mainly because they’re transported on trucks.

This means that a pipeline, no matter how long, is made up of a series of short sections with hundreds or thousands of joints – each one a potential leak. It also means that the pipes often have to be manufactured at distant locations and then shipped and hauled to construction sites over great distances and at great cost.

Ehsani’s InfinitiPipe addresses this problem by moving the manufacturing process to the site itself. He had originally been working on a method to reinforce existing pipes using composite materials. This led to his creating a method for making composite pipes that involved wrapping layers of carbon fabric and plastic honeycomb around a mold called a mandrel. As the pipe was partially finished, it would be slipped down the mandrel while the next length was made.

Then Ehsani realized that he was on to something. "I thought, why don't we just slip this off of the mandrel and continue making this pipe?" Ehsani said. "Never stop."

This meant that the composite pipe could be theoretically infinite – just keep adding honeycomb and fabric, keep moving the pipe down the way and there’s no end to it. In practice, however, there are limits. "We could make a section a mile long," he said. "Of course, every thousand feet (304.8 m) or so, you'd need an expansion joint so the pipe can breathe, but this would certainly not be the same concern we have today, where we have to put a joint every 20 feet (6.09 m)."

Since the InfinitiPipe is made of lightweight materials, transportation costs are much cheaper than for concrete or steel. This makes on site manufacturing an economical proposition. Ehsani envisions a manufacturing unit installed inside of a truck where the pipe would be fabricated and the truck moving forward as the pipeline if fed out.

According to Ehsani, this would have a large impact on both commercial operations, which could move their pipe fabricating trucks anywhere in the world to follow demand, and in the developing world. "Suppose you have a pipeline project in a developing nation," Ehsani said. "You could ship the raw materials to the workers there and they could make this pipe in their own village. No matter what size or shape they want, all they need to do is build a mandrel and make the pipe on the spot. We would be making it with local people under our supervision."

Ehsani is presenting a paper on his new pipe technology at the American Society of Civil Engineers Pipelines 2012 Conference, Aug. 19-22 in Miami.

Source: University of Arizona

About the Author
David Szondy David Szondy is a freelance writer based in Monroe, Washington. An award-winning playwright, he has contributed to Charged and iQ magazine and is the author of the website Tales of Future Past. All articles by David Szondy

If you lay some S-curves into the pipe line and the pipe is as flexible as high strength steel you shouldn't need Expansion joints and it would be less likely to develop leaks. But the choice probably comes down to which costs less the additional pipe, or the additional labor and expansion joint.


A phenomenal idea, and I eagerly wait his adaptation of this tech to roadmaking.

Todd Dunning

I want some tests to see how it performs in the real world before using it to carry hazardous material.


hopefully it'll be cost competitive. often we have better solutions not being implemented because it's more expensive.

Calvin k

If he put a very thin Archimedes screw on the mandrel he could just let it spin it slowly instead of sliding it down the mandrel, but it's a fantastic idea


No mention of the time needed to fabricate the pipe as it's a mutlilayer epoxy system that needs drying time before you slip it off the mandrel.


Probably a good idea to start looking at adding a type of flexible joint into the continous process. Then you can just switch on the machine and start driving. ;-)


i think this would solve the need for expansion joints too

Hahn Jackson

re; Calvin k

Cost is part of the equation in deciding what is the better solution.


Space Elevator! (with smooth shaft for best & vibration-minimized acceleration)...

Green Guru Forever

couple this with that automated brick road layer from europe and you can lay pipe AND create a road in one go!


I'm thinking of all sorts of construction projects from vehicles to homes.


Thank you all for your thoughtful comments. Below are the answers to the questions you had raised. The cost of this pipe is very competitive, especially when you consider that we have little cost associated with transportation and field installation. The pipe is already approved for application in potable water pipes and tanks. Clearly we need to do more tests for other chemicals that may present, such as in natural gas, oil, etc. However, fiberglass pipes that are of lower quality than InfinitPipe are approved and have been in service for such applications. I appreciate your input about flexible joints; certainly something worth investigating. But buried pipes in general are not subject to significant temperature fluctuations and therefore expansion/contraction may not be as big of a concern. At the moment, I believe where this pipe becomes very economical is for transmission lines (that are many miles long) with little need for fittings and in diameters that are larger than 12 inches. While smaller diameters can be made, we loose the cost advantage for transportation.

Pipe Medic
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