Ohio Firm Fights Flatness and ‘Ovality,’ Which Are Real Problems
Bending the tubes that carry natural gas fuel to a natural gas engine can impede performance and increase the risk of failure. It’s an overlooked problem involving geometry and physics, and can be minimized with care and planning and the use of proper materials, AFV Natural Gas Fuel Systems GM Kevin Dickey writes in a recent blog post.
“When bent tube assemblies are being engineered,” Dickey says, “ovality and flattening are often disregarded.” Increased ovality means a decrease in wall thickness on the outside of the bend, which can affect the integrity of the fuel system.
“The best solution can often be to re-route the tube and lessen the angle of the bend,” he says. He details the problem with reference to the diameter of the tubes being bent, wall thickness of the tube, centerline radius of the bend, ovality percentage, and ASME guidelines on the subject.
Ohio-based AFV notes that it has been supplying tube and hose assemblies for natural gas vehicle fuel systems since 2009. The firm offers application assistance, reverse engineering, prototyping, design for manufacturability and assembly, product leak and pressure testing, and supply chain an inventory management solutions, primarily for vehicle retrofitters.
“The fuel line system overall,” Dickey says, “needs to reflect the engineering thought that went into the routing and layout.”
“When it comes to NGV bent tube fuel lines, beauty is in the eye of the beholder.”
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Source: Alt Fuel Express with Fleets & Fuels follow-up