The Dynamics of Trenchless Piercing Tools in the Gas Industry: A look at Nicor Gas

To say that deregulation has prompted the gas industry to become more efficient is a gross understatement. Since its beginnings in the late 1970s to present day, deregulation has reshaped the way business is done in the natural gas industry, putting the focus on competition, lower prices and satisfying the customer. The push for greater efficiency has resulted in dramatic changes in the structure of natural gas utilities and the way utilities approach the various facets of day-to-day business.

This condition has also made gas utilities leaders in the development and usage of new field technologies. Nicor Gas, Naperville, IL is a good example of a gas utility that has improved its efficiency and benefited through the use of new technologies. One type of technology that has certainly made an impact for Nicor is trenchless technology, specifically piercing tools.

According to Paul Adam, Nicor Distribution Supervisor the company’s usage of piercing tools can be partially attributed to deregulation. He said, “The customer definitely expects more these days then they did even 10 or 15 years ago when they knew there was only one supplier in town. They have choices now. With deregulation we have to step it up, be more cost effective and efficient. Using piercing tools on installations and upgrades is one important way we can contribute to that goal.”

Chris Beykirch, piercing tool specialist from trenchless equipment manufacturer TT Technologies, Aurora, IL agrees with Adam’s assessment. He said, “Field operations is a good place to see how gas companies are improving their efficiency. As a trenchless equipment manufacturer, one way we help contribute to that efficiency is by continually trying to improve the reliability and accuracy of the Grundomat tools we provide. When it comes to piercing tools, reliability and accuracy are the two key factors to success.”

Utility Background

Founded in 1954, Nicor Gas is an investor-owned natural gas utility that serves nearly two million customers in northern Illinois, excluding Chicago. Nicor Gas is the largest natural gas distribution company in Illinois and one of the largest in the United States. The company maintains a 29,000-mile distribution system that is connected to seven interstate pipelines. In addition, Nicor Gas transports and stores natural gas for customers that purchase their own gas supplies. These commercial, industrial and residential customers total 129,000.

Adam said, “Our service area is rather large and we’re constantly growing. It’s interesting how we grow. Construction usually starts north of Chicago and then expands out. Within one or two years it’s like a wave that just keeps going from north end, to the central, to the south end and then back up. And that’s how our new business has been. It follows that construction pattern.”

According to Adam, a majority of Nicor’s fieldwork is devoted to upgrading exiting systems and performing new service installations. A smaller portion of work deals with conversions to natural gas. It is in the field, with its distribution centers, where the relationship between Nicor and the piercing tool shines.

Adam said, “Company wide we maintain numerous distribution centers. These centers are located throughout our service area. Each center is made up of six to ten two-man crews, each responsible for a specific area. A majority of the work is maintenance and upgrading of existing lines. To demonstrate the usage of trenchless in Nicor, almost every crew is equipped with at least one piercing tool. We have piercing tools ranging in diameter from 2 1/2 inches through 4 inches. We are also adding some 1 3/4 tools that the crews call pencil shooters or sidewalk shooters.”

Polyethylene Pipe

Trenchless technology flourishes in the gas industry because of the industry’s dedication to customer service and efficiency. It also flourishes because of the gas industry’s wide acceptance and preference for Polyethylene (PE) Pipe. The use of PE is important because it helps facilitate the use of trenchless pipe installation equipment like piercing tools.

According to PE pipe manufacturer/distributor ISCO Industries President Jimmy Kirchdorfer, the relationship between PE pipe and the gas industry is a healthy one. Kirchdorfer said, “The gas industry was really the first utility industry to embrace PE pipe industry wide. One of the big reasons the gas market has accepted polyethylene pipe so quickly is the zero leak factor. They absolutely can’t have leaks. The other important aspect of the use of PE in the gas industry is trenchless technology. There is such a great pairing between trenchless technology and PE pipe. Both of them flourish when it comes to gas distribution and service.”

Adam agreed, “Since we’ve been putting more and more PE in the ground we’ve had fewer maintenance issues. As we replace old copper lines and old steel lines with PE, the less problems we’re having.”

The Piercing Tool Factor

The piercing tool can be used to install PE service lines and mains in several ways. For service lines and mains up to 2-inches, crews commonly pull the new PE in when removing the piercing tool’s air hose. This is usually done with pipe diameters of 2 inches and smaller. Basically the crew completes the bore, removes the tool, attaches the new pipe to the air hose and then pulls the new pipe in place using the hose. Typically other crewmembers will assist in the process by pushing the PE from the other end if needed.

Another way to install PE pipe is to attach it directly to the piercing tool using a threaded PE pipe adapter. This is typically done with larger diameter pipe, from 2 inches through 6-inches.

According to TT Technologies’ Beykirch, this method is sometimes modified in certain soil conditions. He said, “In sand or loose soils that tend to collapse quickly, sometimes crews will pull in a larger diameter pipe with the Grundomat, then insert the smaller diameter service or main into the larger pipe. This is called a slip bore. The larger pipe can then be removed or left in the ground.”

Finally, when installing small diameter pipe, 5/8-inch through 1 1/4-inch, the pipe itself can be used as the piercing tool’s air hose by utilizing an air nipple. By making the product pipe function as the air hose, the crew simply removes the tool once the bore is complete and everything is in place.

On The Job

A typical service line installation for a new service or upgrade consists of two or three bores, ranging anywhere from 50 to 75 feet in length. Because the service area of Nicor Gas is so large, soil conditions can vary greatly from job to job.

Adam said, “We get a mixture of everything here. You might be in an area one day with a lot of clay and mixed soil and then the next job you encounter rock, lime and bedrock. Along the Fox River you get quiet a variety of soil conditions so it just depends where you’re at.”

Dealing with the variety of soils makes the accuracy and power of the piercing tools extremely important. According to Adam in the past Nicor utilized moling technology (mole rods) for main and service line installations. This process, however, is sometimes questionable in the field.

Adam said, “The moling equipment works like a big drill. It consists of rods and various sized drill heads. The rods are connected to a motor. As you mole, more rods are added. It’s not very accurate; it’s not very reliable and it’s not very cost effective either. The rods are expensive and it’s possible to use them just one time and bend them.

The Grundomat is just the opposite. It is time saving, cost effective and reliable. It’s a reliable tool because you know that when you set it, it’s going to make it through and you’re going to find it on the other end.”

According to Beykirch that accuracy and power is due in part to a unique design. He said, “The Grundomat’s major improvement over standard piercing tools is its reciprocating head. The chisel head assembly moves independently of the main casing, assisted by a spring, creating a pilot bore for the rest of the tool body to follow. This ultimately leads to greater bore accuracy. The chisel like action helps the tool to power through difficult soils and obstructions without being pushed off course.”

Trenchless Beneficiaries

Nicor Gas is not the only beneficiary of trenchless technology. The customer ultimately benefits as well. Adam said, “The customer really benefits from trenchless equipment like piercing tools by not having to be inconvenienced by the disruptions associated with other non-trenchless pipe installation methods. Their lawns and landscapes remain intact. Driveways do not need to be torn up. And roads can remain open while trenchless installations are being performed.

We can achieve more with smaller crews and save substantial amounts of money on restoration costs. It really is a win/win situation for everyone.”

 

by Jim Schill

Pipeline & Gas Journal, January 2002