Custom Stainless Steel Fuel Nozzle Seal

This featured fuel nozzle seal is used on a Pratt & Whitney JT8D jet engine – the power plant for thousands of MD-80 and DC-9 commercial aircraft in the sky today. Our engineering staff worked with Pratt & Whitney engineers to design the critical features of this part. To manufacture the seal, a variety of CNC machining processes were applied with custom made tooling. Using a twin spindle Traub lathe with live tooling, we turned each side, with both sides requiring a dual spring diaphragm, with a .0002″ to .0005″ knife edge radius on both the I.D. and O.D periphery. The knife edges were selectively nitride coated for hardness. Four slots at 90 degrees were CNC machined into the sealer support area below the knife edges. Twelve equally spaced .123″ to .127″ holes were drilled into the face. Throughout the machining process we maintained tight tolerances of +.0002″-004″, and a concentricity tolerance of .0005″. To conduct inspection we relied on an OGP touch probe and a vision system CMM, as well as micrometers, pin gages, a custom thread gage, a drop gage, and an optical comparator. Each seal is 100% inspected under a 20X power microscope for any visual imperfections and 100% vacuum tested for sealing.