Grantee Research Project Results
Final Report: Reduced Cost Sewer Pipe Relining Using Ultrasonic Tape Lamination
EPA Contract Number: 68D01054Title: Reduced Cost Sewer Pipe Relining Using Ultrasonic Tape Lamination
Investigators: Player, John
Small Business: Foster-Miller Inc.
EPA Contact: Richards, April
Phase: II
Project Period: September 1, 2001 through September 1, 2003
Project Amount: $224,867
RFA: Small Business Innovation Research (SBIR) - Phase II (2001) Recipients Lists
Research Category: SBIR - Pollution Prevention , Nanotechnology , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
Description:
During this Phase II research project, Foster-Miller, Inc., adapted and optimized its Ultrasonic Tape Lamination (UTL™) technology for sewer pipe liner joining. The developed techniques are adaptable for rehabilitating existing infrastructure and have been demonstrated for new construction. Foster-Miller demonstrated ultrasonic welding of Ameron plasticized polyvinyl chloride (PVC) pipe lining material. Weld strengths comparable to state-of-the-art hot-air welding methods were achieved at rates of up to five times faster.
Plunge welding with ultrasonics was down-selected as the most reliable approach for welding PVC seams on concrete surfaces. A prototype mobile sewer pipe relining system was designed, built, and demonstrated based on this method. Foster-Miller used the prototype system to install two PVC liner segments in a man-rated sewer pipe at rates two to five times faster than the current state-of-the-art PVC lining process, while maintaining the 2,000 parts per square inch (psi) weld strength requirement.
Summary/Accomplishments (Outputs/Outcomes):
The primary goal of this Phase II research project was to design and fabricate a field-deployable ultrasonic system capable of rapidly joining sewer pipe liners during the rehabilitation of existing infrastructure in new construction. Foster-Miller experimented with a range of 20 kHz ultrasonic welding methods to expand on the success of the Phase I research project, during which the goal seam shear strength of 2,000 psi was achieved at welding rates five times faster than the current state-of-the-art seaming technique, the hot-air welding method. The primary goal was to determine if alternate 20 kHz welding methods, such as radial or continuous shear welding, would provide greater rate capability while maintaining high weld quality and the goal shear strength. In both alternate methods, the ultrasonic tool makes continuous contact with the pipe liner throughout the welding process over the full length of a seam. In contrast, the conventional plunge welding method used in Phase I to demonstrate the 5-fold rate increase requires the ultrasonic tool to be repositioned for each weld cycle. Ultimately, the most promising alternative higher rate welding method, radial welding, as well as the continuous shear method, were found not to provide sufficient weld quality. The plunge weld method, which provided the highest weld quality, was down-selected for process optimization and carried through the remainder of the program.
Once the plunge welding technique was optimized, Foster-Miller designed, fabricated, and demonstrated a field-deployable mobile seam welding system. A photograph of the field deployable Phase II system is shown in Figure 1. The Branson Ultrasonics Corporation collaborated with Foster-Miller to design and build a cost-effective, field-deployable ultrasonic lamination system based on their commercial products. Locally, the Massachusetts Department of Environmental Protection (MassDEP) and the Massachusetts Water Resources Authority (MWRA) supported the team in an advisory role.
Figure 1. Photograph of the field deployable Ultrasonic Welding System
Conclusions:
The existing water and sewerage infrastructure is in great need of nationwide rehabilitation. The cost-intensive nature of the existing rehabilitation techniques has driven the U.S. Environmental Protection Agency (EPA) to pursue new technologies that have the potential to significantly reduce the labor time of relining these infrastructure systems. There is a wide range of pipe sizes associated with these systems. Much of the technology development to date has focused on the smaller diameter, typically less than 24 inches. Foster-Miller was given the opportunity to adapt its UTL technology for welding PVC pipe liners for the larger man-rated sewer pipes (more than 48 inches in diameter). This category of sewer pipes represents 5 percent of the pipes needing rehabilitation and has been estimated to comprise roughly 30 percent of the cost of the national rehabilitation effort.
During this Phase II research project, Foster-Miller explored multiple 20 kHz ultrasonic welding methods capable of welding PVC liner material and down-selected plunge welding, the most reliable technique for optimization. During the optimization process, Foster-Miller explored the range of welding control schemes as well as the range of process parameters and established the most repeatable combination for use in the remainder of the project. This control and process parameter combination enabled welding process rates of 15 inches per minute, a factor of five times faster than the state-of-the-art hot-air welding technique.
Once the plunge welding technique was optimized, Foster-Miller incorporated key ultrasonic equipment components from its team partner, Branson Ultrasonics, to design and fabricate a prototype mobile welding system suitable for man-rated sewer pipes. The design incorporates many off-the-shelf ultrasonic components that provide a cost-effective mobile welding unit for the sewer lining rehabilitation industry.
The demonstration phase of the project illustrated that the ultrasonic welding system could be adapted for welding PVC liners successfully over rough cement surfaces with repeatable results. Seams along both the circumference and the length of the demonstration sewer pipe section exhibited good quality and appeared to be fully sealed. The seam welding demonstration using the prototype mobile system was documented in video format and is being made available to the EPA, MWRA, MassDEP, Boston Water Sewer Commission, and Ameron.
Foster-Miller recommends that future research make use of the mobile system in new projects and rehabilitation projects to determine the specific design improvements useful for the field environment. If additional welding rate improvements are desirable, it is recommended that additional funding be made available for developing the necessary radial ultrasonic welding equipment modifications to enable this as a continuous ultrasonic welding method.
Journal Articles:
No journal articles submitted with this report: View all 1 publications for this projectSupplemental Keywords:
sewer pipe relining, ultrasonic seam welding, Ultrasonic Tape Lamination, UTLTM, polyvinyl chloride, PVC, hot-air welding, plunge welding, sewer pipe, infrastructure rehabilitation, urban infrastructure, pipe liner, mobile welding system, small business, SBIR., Scientific Discipline, Water, Civil/Environmental Engineering, Civil Engineering, Engineering, Engineering, Chemistry, & Physics, Environmental Engineering, Ultrasonic Tape Lamination (UTL), sewer pipe, water pipe, infrastructure , Massachusetts Water Resources Authority (MWRA) , Massachusetts DEPSBIR Phase I:
Reduced Cost Sewer Pipe Relining Using Ultrasonic Tape Lamination | 2001 Progress Report | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.