Truck works is not using hot-dip galvanizing on liquid transportation tanks.
Truck Works Inc. (TWI), a Phoenix, Ariz., based corporation and an original equipment manufacturer (OEM), integrated a proven technology with a new application.
This new cost effective solution involves an old technology by hot-dip galvanizing (HDG) liquid transportation tanks. Previous to this new HDG application, customers’ options were limited to applying an epoxy coating over bare steel or costly aluminum and stainless steel.
Epoxy coating, a commonly used element in the industry, has an inherited downside. If the coating is improperly installed or damaged, the steel underneath is exposed and corrosion occurs. Aluminum and stainless steel, although having extreme resistance to corrosion, has a much higher price tag, making it virtually unfeasible for most applications.
Corrosion of steel caused by exposure to atmosphere, soil, water or chemicals could be eliminated by 25 to 30 percent by the use of corrosion protective methods such as painting or powder coating, using stainless or weathered steel, and hot-dip galvanizing, according to TWI. However, the process of HDG provides a uniform coating of zinc, which seals the steel from corrosive environmental contact. Many may perceive HDG as cost prohibitive on an intial cost basis, but due to regular process improvement, HDG has become more competitive (and often less expensive) on an initial cost basis than other corrosion protection systems. Furthermore, because galvanized steel requires no maintenance for 70 or more years in most environments, it is often two to six times more economical on a life-cycle basis (AGA).
Despite the difficulty of predicting corrosion, it is important to note that galvanized coatings on steel used in submersed applications is still one of the best methods of corrosion protection. HDG process involves fully immersing fabricated steel in molten zinc, which leaves the steel with a metallurgically bonded alloy coating. This HDG process is currently available in the 1,500 to 4,200 gal. configurations for use in non-potable liquid transportation applications. It is important to note that the HDG process relieves the stress of the steel tank that it incurs while being rolled and welded together, according to TWI.
Coating or painting steel does improve the lifetime of the tank; however, in combination with galvanizing the tank is where the greatest return can be found. Test results show that suitable paint coatings on galvanized steel achieves a synergistic effect in which the duplex coating (estimated painting coating life + estimated galvanized life (x 1.5)) lasts up to three times as long as its equivalent paint coatings on black steel.
It is common for HDG steel to perform flawlessly in harsh water environments such as seawater for eight to 12 years. HDG also can sustain wide temperature ranges as well as a pH range of 5.5 to 12 without suffering a higher rate of zinc corrosion. HDG can contribute positively to sustainable development initiatives because of its longevity in corrosion protection, 100 percent recyclability, and minimal environmental impact (AGA). The HDG coating consists of more than 98 percent zinc metal, which is not only naturally occurring but is 100 percent recyclable without the loss of any properties. Further, because galvanizing provides maintenance-free corrosion protection for 70-plus years, it does not require additional energy, materials, or environmental impact expended to constantly maintain the coating (AGA). This equates to reduced service repairs and adding life to equipment by eliminating the need to replace the tank as frequently, thus improving the overall value for investment
HDG tanks are offered with a greater warranty period than they have previously offered on TWI’s painted steel or lined tanks. TWI is currently testing this product and is in the formal process of acquiring potability certification from the National Sanitary Foundation (NSF). Once the certification is acquired, TWI will expand the availability of this process for use in other markets besides the potable water arena, as its first strategic move with focus toward other industries seeking cost effective solutions to additional liquids transportation.
For more information, visit www.truckworksinc.com.