Novel Sealing Solution for Natural Gas Systems

The Challenge

Our client, Hexagon Agility manufactures fuel systems for natural gas. 

Their key market: Heavy Vehicles Running on Natural Gas

Our key focus: The fuel storage system

The biggest issue: The assembly process for this portion of the fuel system is long and costly

The problem given to our team: Reduce the assembly time on the natural gas tank system

Iterative Design

The sandwich-style seal was chosen due to its simplified design via symmetry, in addition to it being the client's preference. It also ensured that wear on the line due to vibration would focus on the easy-to-replace seal, rather than an area where the two metal plates met. Once the type of seal was determined, another iterative design process began on the body of the system. A round and flat design emerged, focusing on aesthetics and pure functionality respectively. Each of these designs was 3D printed to give an idea of how they would fit into the system overall. During this phase, many small changes, such as bolt locations and wall thicknesses were made. These changes emerged from short comings found when physically interacting with the prototype, and became the foundation for the final iterations for the design. 

Testing and Implementation

For the final stage of the project, three major tests took place. The first was a fit test, done with a 3D printed prototype. The purpose of this test was to ensure that the design would fit over the existing fuel line material, and seal completely. It also helped identify potential failure points, where the clamp did not fully compress the seal against the fuel line. This led the final design to incorporate 4 bolt holes, which ensured an even clamping pressure for the seal around the fuel line. Based off the revisions made during the fitting test, a final metal prototype was ordered. This prototype was then fitted to the fuel line, and two tests were conducted, outlined in the table below. A pressure test was run, to ensure the seal would hold at operating conditions. While the true design performance was not met in this test, it was due to issues with the fuel line and not the clamping seal itself. It was determined the seal should meet the full pressure specification, and will  be tested in the future. A leak test was also conducted, which fully passed, meeting all design specification requirements.

Learning and Growth

This iterative process taught me the importance of:

• Iterative Prototyping: Rudimentary prototypes actively help guide the design process, and allow for more feedback than digital models can

• Client Collaboration: Actively incorporating client expertise and requirements into the design process.

• Adaptability: Being willing to pivot and explore new design directions based on testing and feedback. 

In addition, I worked to develop my ability to effectively communicate throughout this project. I took the role of presenting at client update meetings and for final term reports. This helped build my overall skills for effectively communicating my key ideas. I also worked on gathering client needs throughout these meetings, and communicating how our interpretations of these needs changed as the project progressed. All of these have helped build my career skills and advance my skills in engineering, communication, and project management.