With over 1,300 linear feet of various-sized steel pipe needing to be lined, Trinity River Authority's (TRA) Central Regional Wastewater System (CRWS), an influent pump station in Dallas, Texas -- along with the pipe fabricator involved -- decided to apply an innovative ceramic epoxy lining from Tnemec Inc., a manufacturer of coatings and coating systems for exterior and interior environments.
Tnemec's Series 431 Perma-Shield PL is a coal-tar-free, modified polyamine ceramic epoxy with low pigment volume concentration, as well as a 100-percent solids formulation for maximum performance. When tested using rapid evaluation of coatings and linings (the Severe Wastewater Analysis Test [S.W.A.T.]), Series 431 remained in the "excellent" range after 28 days of exposure.
"The area and its wastewater facilities have a history of specifying a different lining system," said Rick Penner of Midwest Coating Consultants Inc. "But Series 431 Perma-Shield PL offered them equal or better performance and was easier to apply, so they chose the Tnemec system."
The pipe was manufactured and coated in the city of Scammon, Kan., before being shipped to Dallas. Representatives from the corresponding states worked together to achieve a quality end result.
"John Barry from The Barry Group LLC in Texas worked very hard with the engineer to make sure they had a quality specification," said Penner. "I worked with the applicator to ensure surface preparation and application went smoothly. Mid America Pipe already has excellent internal quality standards, so they were very accommodating with our recommendations."
The interior of all pipes was prepared according to SSPC-SP5/NACE 1 White Metal Blast Cleaning with a minimum 3-mil profile. With the majority of the pipe being as large as it was, the applicator stood inside the pipe to spray-apply Series 431 at 40- to 50-mil dry film thickness (DFT). The lining was applied to the smaller steel pipe with a rotary spray gun using the same plural component equipment as the other pieces.
"The owner enjoyed the lining enough that they approved using Series 431 for another project connected to the wastewater plant," said Penner. "And all parties involved that have seen the lining after application, in the shop and in the field, were truly impressed with the look and consistency of the end result."
The Central Regional Wastewater System currently serves 21 contracting parties and approximately 1.2 million people in the Dallas/Fort Worth area. It is capable of providing complete treatment for monthly average flows of 162 million gallons per day (MGD), while removing 99 percent of conventional pollutants from raw wastewater. WWFor more information, visit www.tnemec.com.
More WaterWorld Current Issue Articles
More WaterWorld Archives Issue Articles
