Accessories Service and Overhaul Capabilities A sample of our capabilities is listed below. If you don’t see what you are looking for, please call us. Fuel Systems Pumps, Fuel Amplifiers, Refuel/Defuel Panels and Valves Environmental Systems Environmental Control Units (ECUs), Turbo Compressors, Outflow Valves, Flow Limiters, Heat Exchangers, Mixing Valves, Shut Off Valves and Fans Other Systems Fire warning and control systems, master warning systems, brake systems, de- ice systems, hydraulic systems.