A gold-mining operation in South Africa required cooling water for its equipment and refrigerated air throughout the mine. Due to the mine's depth, rock-wall temperature reached 120oF (49oC). If refrigeration was lost, all 6,500 miners had to be evacuated immediately.
Wichita Falls, Texas-based Tranter developed a shallow pass-plate banked in a 35-plate cooling module to satisfy the mine's specific requirements. Dies were built to press the plates, and fatigue-testing verified that the unit could withstand pressure variations inherent in the operating cycle. A sample coil was exposed to more than 1.2 million cycles from 30 to 75 psig, and it did not leak.