Specialized Expansion Joints for Marine Engines
Product Announcement from American BOA, Inc.
Northrop Grumman Avondale Industries recently contracted with American BOA to design and build the expansion joints required for the T-AKR Sealift vessels powered by diesel engines. The LMSR's (Large, Medium-speed, Roll-on/Roll-off) ships can carry an entire US Army Task Force, including 58 tanks, 48 other track vehicles, plus more than 900 trucks and other wheeled vehicles.
Each vessel requires (16) 36" and (2) 54" expansion joints for the four engine exhaust system. The challenging design required: (a) very low natural frequencies to allow resonance during start-up and each bellows location had unique requirements depending upon orientation and firing order; (b) total movement and vibration stress needed to be extremely low (<20,000 psi); (c) aggressive vibration required the 5 ply universal bellows to use special convolution geometry; (d) bellows were produced from Inconel 625LCF to resist salt water chloride attack; and (e) each unit had to fit into a piping space less than three feet long.
To learn more about the ways that American BOA can assist with expansion joints in your challenging application click on the product details weblink on the right or e mail your inquiries