A 5-person Lehigh capstone project sponsored by Westlake Pipe & Fittings — designing and building a testing apparatus to run high-cycle fatigue tests on restrained joint integral bell (RJIB) PVC pipe systems, targeting compliance with ASTM F1674 and UL requirements.
This was a five-person Lehigh ME capstone team (Brennan Cruz, Max Peinkofer, Layne Raczy, Benjamin Ratner, and Nathan Sugimoto) sponsored by Westlake Pipe & Fittings. The brief was to design and build a testing apparatus capable of high-cycle fatigue testing on restrained joint integral bell (RJIB) PVC pipe systems — widely used in municipal water infrastructure — and to work toward compliance with ASTM F1674 and UL requirements.
Beyond the apparatus itself, the team was also asked to provide design recommendations for improving RJIB pipe performance based on the failure modes observed in industry and in testing.
Our team started with stakeholder research, interviewing general contractors, a nuclear maintenance engineer, a civil engineer, and a strength-of-materials professor to understand real-world failure points, then built a needs/metrics matrix and a risk-assessment plot to prioritize which subsystems to prototype first.
Utilizing a function diagram, our explored several full-system design concepts: a pneumatic design using a pressure magnifier and regulated air over water tank, a hydraulic design using a linear actuator against a piston, and a design using a positive-displacement pump paired with an accumulator tank and a PLC for closed-loop pressure control. An early accumulator prototype, built from a 2 liter soda bottle and a balloon, validated the basic pressure-response concept before committing to a full prototype build.
A Failure Modes and Effects Analysis (FMEA) guided where to add redundancy and refine the design for reliability and safety. During final testing, the team found the pressure regulators weren't behaved as expected and reconfigured the apparatus, with input from Westlake, to get a proper pressure cycle.
The reconfigured apparatus produced a pressure curve that behaved as hoped, demonstrating clear, repeatable control over base and peak pressure using just an on/off valve — validating the core approach for cyclic pressure testing.
The team's final design was a working, semi-automated prototype that logged complete pressure cycles rather than a fully automated system. Solenoid valves, a digitally controlled regulator, and full PLC integration were identified as the next steps needed to run the apparatus unattended through the full one-million-cycle test specified by ASTM F1674 — work the report lays out for Westlake or a future capstone team to pick up.
The complete capstone final report — covering stakeholder research, design ideation, FMEA, FEA, and final testing results — is available as a PDF.
Read the Full Capstone Report (PDF) →