ZERUST® VCI Packets Preserve the Internal Surfaces of Fuel Tank Systems During Shipping and Storage

Problem

The world’s largest construction equipment manufacturer had a facility that fabricates and assembles power systems on skids for the Oil & Gas industry. The equipment manufacturer was in need of internal corrosion prevention of the fuel tank for the power system. The 1,650-gallon fuel tank was fabricated into the base of the skid assembly, using carbon steel alloys. They previously coated the interior walls of the baffled fuel tank system with a mixture of a Vapor Corrosion Inhibitor (VCI) additive and diesel. The coating was accomplished by rotating the massive skid’s base 360° on the horizontal axis. A uniform coating of the diesel/VCI mixture was completed after several rotations. The engineer wanted a solution that’s more efficient with regard to both labor and resources, to apply a VCI remedy to the internal surfaces of the fuel tank.

Solution

The manufacturer required 1 year of corrosion prevention in a closed (sealed) fuel tank system. ZERUST® initially discussed fogging a mixture of Axxanol™ 710C and diesel, after rinsing the system with AxxaVis™ HST-10 which thoroughly cleans the organic soils from all metal interior surfaces. This approach seemed plausible, but left concerns for moisture entrapment of the HST-10 in the baffled areas and Axxanol™ 710C had yet to be vetted as a compatible mixture with diesel. The discussion turned to the use of a VCI powder alternative, but consideration had to be given to both the deployment and removal of the powder. ZERUST® looked to ActivPak®-35 VCI diffuser packets as a product that would fill the entire vapor space, given an adequate number of packets could be inserted into the fuel tank. Retrieval of the packets was a concern, as failing to remove an individual packet could result in a fuel blockage scenario. There were a limited number of ingress points to insert the ActivPak®-35 packets and the opening size was close to 8”. ZERUST® developed a ActivPak®-35  VCI packet container that would fit down the (8) service points and was sealed with a threaded steel cap. A flanged lip was welded to the rim of the fabricated container, suspending it in the steel-capped area. The body of the steel was slotted with multiple vents, to allow adequate dispersion of the ZERUST® ActivPak®-35 packet VCI vapors into the vapor space.