FEATURE PRIMARY & SECONDARY CONTAINMENT SPRAY, COAT AND CONTAIN
Flexible polyurea coating from VersaFlex, provides seamless containment for industrial facilities and field applications
W
hen used for primary or secondary containment, traditional coatings
have been too inflexible and not sufficiently elastic to accommodate ground, concrete or metal substrate movement. This deficiency can lead to cracks or holes developing in both the substrate and the coatings, which can compromise containment. However, the formulation of tough,
monolithic, flexible coatings such as polyurea are now resolving this issue for contractors, engineers, and facility managers. When applied directly to concrete or metal surfaces, polyurea not only reinforces and protects the underlying substrate, but can also bridge gaps or cracks of 1/8” or larger. Furthermore, polyurea is now being pre- applied to geotextile liners that can be quickly rolled out in sheets to protect more heavily damaged surfaces or for use in field applications such as dirt or gravel pads at drilling sites. Once installed, applicators need only coat the seams of the liners to create a monolithic surface suitable for containment. Whether at refineries, industrial plants, or other manufacturing facilities, regulations demand the use of primary and secondary containment systems to keep toxic or hazardous substances from escaping into the ground and potentially entering the water supply. This implies primary containment
(typically via a concrete or metal storage vessel that holds chemicals or liquids) is not foolproof. Though durable, metals corrode, concrete cracks and is porous as well, so will leach liquids if uncoated. Therefore, secondary containment, in the form of concrete pits with barriers installed around the perimeter of a tank or other storage container, is often required. To protect these structures, coatings
such as epoxies, tars, and polyurethanes are often applied as an added barrier of protection. However, these traditional coatings are often inflexible when cured and can crack along with the concrete. “Typical coatings do not hold up well to substrate movement or daily, seasonal, or process-related thermal expansion and contraction, which can lead to cracks and leaks,” said Jim Collins, co-owner of South
44 JULY/AUGUST 2017 | PROCESS & CONTROL
variations of temperature and humidity. “After spraying the polyurea, return to service is almost instantaneous, which can make a big difference in minimising production downtime,” said Collins. “We coated about 8,000 sq. ft. of concrete in 12 truck-offloading areas that required drive-in containment with VersaFlex polyurea. Within minutes of spray application, trucks were safely driving across it.” In some instances, instead of spraying polyurea directly to the substrate, pre- sprayed composite panels can offer advantages for containment over soil, gravel, or even concrete that is too damaged to be effectively rehabilitated. “For primary containment at oil field
Penn Resources, a US-based producer of containment systems. After considerable research and testing,
Collins says he turned to an advanced polyurea system from VersaFlex, a manufacturer of spray applied polyurea for primary and secondary containment. When applied to substrates such as concrete or steel, the spray-applied waterproof coating creates a durable, seamless, flexible, protective barrier that stops leaks and strengthens the integrity of primary and secondary containment systems. The coating exhibits superior physical properties such as hardness, tensile strength, as well as crack bridging and elongation up to 400%, to create a robust, industrial-grade protective lining. “Polyurea can bridge cracks as well as flex at a rate similar to concrete and steel,” said Collins. “This not only helps it last but also seals the concrete so it does not absorb contaminants if there is a spill inside the contained area.” While traditional coatings such as
cementitious, epoxies, tars, and polyurethanes will prematurely fail if not installed under a relatively narrow range of temperatures, polyurea is designed for installation and use from -40°F to +350°F. It sets and cures quickly and will withstand decades of freeze-thaw cycling, and wide
Secondary containment, in the form of concrete pits with barriers installed around the perimeter of a tank or other storage container, is often required as a back-up to primary containment
drilling sites, we used to put various plastic systems on the well pads, but we moved away from that because plastic was not durable enough,” said Collins. Repairing plastic liners also presents a
problem at the seams, when damaged areas are cut out and new sections welded in. As a solution, Collins turned to geotextiles with pre-applied polyurea for durability and reusability benefits. “Polyurea products are so much more durable than plastics for containment systems,” he said. “When needed, we can custom apply more polyurea millage to geotextile panels and berms to accommodate even the heaviest truck use and vehicle abuse.” To verify the strength of the polyurea
coating on containment mats and berms, in fact, Collins conducted a number of tests. “I ran an 11,000 pound skid loader onto a containment mat, stood the forks straight up and tried to puncture it – but it did not puncture through,” he said. “We also ran 6,044 fully loaded water trucks across a containment system and it withstood it with zero holes and no compromise to the liner.”
After spraying the polyurea, return to service is almost instantaneous
Collins credits both the durability of the VersaFlex polyurea as well as its extended recoating window for the ability of his company to extensively reuse its containment systems. “To reuse a containment system, we’ll
cut it up into rolls, roll it up and move it. Then we’ll take it back out, respray certain areas, and reinstall the original containment system at another location,” explained Collins. He concluded: “We’ve found the extended open window for recoat and repair of the VF380 polyurea allows us to easily cut out any damaged section of geotextile, put a new piece in, and spray the seams to make it virtually seamless again. We get better repair and more reuse out of our containment systems.”
VersaFlex
www.versaflex.com
/ PROCESS&CONTROL
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61