9x and LEAP Nozzle Pressure Test Vessel

Redesigning a Pressure Test Vessel for Safety and Ergonomics

This Project was the first project I completed outside of an academic setting. This project was assigned to me as a sort of educational/trial project at my first internship, and I worked closely with several manufacturing engineers to complete it. Unfortunately I was unable to obtain images of the completed project upon its completion. The goal of the project was simple, improve the design of a pressure test vessel that could be used to test two similarly sized fuel nozzles, the 9X and LEAP. There was a currently existing pressure test vessel for the nozzles which worked, but were quite heavy leading to ergonomics and cost issues related to its use and assembly.

My first task of the project was to determine what could be changed to improve the design. I started by running some calculations to determine the factor of safety on the device. While I don't remember the exact factor of safety I do remember it was much larger than it ever realistically needed to be, somewhere in the ballpark of 35. I presented this information to the engineers overseeing me and suggested that we reduce the thickness of the pressure vessel, which they approved of. I drastically decreased the wall thickness of the device, lowering the factor of safety from 35 to 10 keeping it more than enough for safe use. This reduction lead to the overall weight and material cost of the vessel halving.

The Project was not complete however, the walls of the new design was too thin for the old screws used to hold the nozzles in place. Screws of decreased length could not be used as the force of the pressure vessel was high enough to prevent their safe use. Upon bringing up this issue to the engineers overseeing me they directed me to use whatever solution I saw fit but focus on keeping the weight to an absolute minimum. With this constraint, and after evaluating several options ,I decided to double the amount of securing screws decreasing the force on an individual screw and improving bringing the factor of safety on the screws up to the same level as the rest of the pressure vessel. Following this final addition, the vessel was complete and it was ready for a design review. The design was approved quickly and several were made for use on the factory floor.

As stated earlier I worked closely with a group of manufacturing engineers while working on the project. The group mainly oversaw and checked my work to ensure I did everything correctly, however, I did go to them for help or advice from time to time. Overall my work was very good, I had thoroughly checked my calculations by the time I presented them to the team and there were never any issues on that front. However, since I was just an intern and had never done any work in which I had to actually design something they helped extensively with the design process, giving me advice on how and what to do.

I would consider the project a success, partially because the new design was accepted but more so what I learned. In terms of engineering no part of the project was particularly difficult, but I learned many important lessons on how to work as an engineer. In addition, the success of this project built my self confidence in a way that academic work never could have. Going forward this confidence would push me to take on projects that I knew would push me and force me to expand my engineering skills.