Process heat medium heater stack under construction showing lift lugs at top and painter’s trolley rails near top of stack. Combustion air preheat duct for refinery process furnace. Construction of top panel of convection section of process refinery furnace showing bullhorn anchor clips for castable refractory. API furnace vertical cylindrical heater modular panel; sized to permit shipment to refinery site for modular assembly. Convection section of API fired heater showing transition section to stack. Process furnace modular sections are sized to suit road transport restrictions to plant refinery site. Alloy coil convection section with castable refractory insulation; ready for shipment.