Shenandoah National Park in Shenandoah, VA, and the Federal Highway Administration (FHWA) recently completed a culvert rehabilitation project using Snap-Tite® from ISCO Industries, LLC. The scope of the rehabilitation project included 56 decaying corrugated metal culverts with inside diameters ranging from 18-inches to 36-inches.

Slip-lining to rehabilitate lines is a classic application of high-density polyethylene (HDPE) Snap-Tite piping and its patented HDPE pipe joining system. This project was unusual because traversing the Appalachian Mountains required installing pipe on slopes as steep as 60 degrees. Such limited working areas further heightened the advantages of the Snap-Tite system.

Although the job initially specified cured-in-place technology to re-line the pipe with synthetic material, JSI Paving & Construction, Springfield, VA, contractor, was given a chance to bid the project using Snap-Tite. JSI won the award and set to work on the three-county project.

The Park’s objective was to rehabilitate these culverts without damage to the environment and to save money. According to the cost study conducted by Shenandoah National Park and JSI, using Snap-Tite will result in a cost saving of $200,000.

“This is an ideal solution for the Park system,” says Jeff Stack, co-owner of JSI. “The customer is getting all the advantages of Snap-Tite – a better, stronger, longer-lasting pipe – in a cost-effective package.”

Rehabilitation of 4,800 linear feet of pipeline was completed on time in November 1999. Ten-foot sections of Snap-Tite were supplied in order to ease installation and to preserve the surrounding existing trees and underbrush. Since there was no need for special equipment to join the pipe, JSI was able to line the culverts successfully with minimal disturbance to their surroundings.

In addition to ease of installation and the watertight performance of the joints, the physical characteristics of the pipe offer many advantages:

• Snap-Tite is made from HDPE solid wall pipe, a lightweight, flexible material. HDPE weighs 70 to 90 percent less than concrete, cast-iron, or steel pipe of the same dimension, which facilitates material handling on the job site.

• The extremely smooth inside surface of Snap-Tite delivers excellent flow capacity. Snap-Tite HDPE has a lower Manning roughness coefficient (0.009) than concrete or corrugated metal, so it's extremely slick. Its Hazen Williams flow factor is 155. In many applications, the Snap-Tite liner will handle greater flow than the existing concrete or corrugated metal being rehabilitated.

• Snap-Tite demonstrates outstanding resistance to chemicals and corrosion. In addition, it is extremely durable and resistant to abrasion.

Snap-Tite’s Long List of Advantages
Ease of installation is one key to Snap-Tite’s many advantages over culvert replacements. In fact, several studies have shown that the largest expense item with culvert repair projects is not the pipe itself but the installation, maintenance, road repair, and liability costs. The Snap-Tite system saves on labor costs by eliminating the time-consuming process of cutting and repairing roads. There’s no need for specialized equipment or special training, so costly equipment rentals and additional labor also are eliminated.

Once the old culvert is flushed and inspected to ensure that a liner pipe can be inserted without any obstructions, a four-person crew can easily rehabilitate a single 80-foot culvert using only shovels, a backhoe, and come-along chains.

Precision machining of the joint component on the ends of the of PE 3408 HDPE pipe creates a system of grooves. Out in the field, the pipe sections are properly aligned and “locked” in place to create watertight seals.

Summary
ISCO Industries, Inc., a technology leader in the HDPE industry, is a fabricator and manufacturer of HDPE piping products. Offering several stocking locations, its corporate headquarters are in Louisville, Kentucky. ISCO manufactures Snap-Tite® at a plant near its corporate headquarters, as well as its facilities in Startex, South Carolina and Shafter, California. For more information on ISCO Industries, visit www.isco-pipe.com or call 1-800-345-ISCO.

For more information, call ISCO at (800) 345-ISCO, or locate your regional sales representative.

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