Automated leak tester for aerospace ball valves at Collins Aerospace

Company overview

Collins Aerospace is a global leader in technologically advanced and intelligent solutions for the global aerospace and defence industry, known for its stringent quality and safety standards.

Executive summary

The development of a custom leak tester has provided Collins Aerospace with a state-of-the-art solution, featuring:

• A highly automated testing process with automated changeovers for multiple valve types.
• Continuous and precise control over all critical test parameters, including flow, pressure, and temperature.
• Integrated validation and calibration capabilities to ensure persistent measurement accuracy.
• A robust, modular design that ensures reliability and operator safety.

Project objectives

Collins Aerospace required a solution to:

• Design and construct an advanced leak test stand for aerospace ball valves.
• Achieve the highest possible degree of test automation with minimal operator intervention.
• Implement continuous monitoring and control of the working medium's flow, pressure, and temperature.
• Incorporate the ability to validate and calibrate the tester using specially made gauges.

The challenge

The project's main challenge was to create a highly automated system capable of performing complex leak tests on three different types of ball valves. The solution demanded precise, continuous control over both a high-pressure (35 bar) pneumatic system and a sophisticated hydraulic system. A core requirement was to integrate a reliable method for validation and calibration to meet client procedures. The entire system had to be engineered to meet rigorous aerospace standards, with a paramount focus on operator safety.

The solution

A comprehensive leak test stand was designed and built on a modular ITEM aluminium profile frame. This frame is logically divided into four zones: a working area with a convenient rotatable control panel, an air and hydraulic preparation zone, a drying chamber with bubble test capability, and a main control cabinet. The working zone is engineered for maximum automation, facilitating valve rotation and changeovers between three types of ball valves.

The stand features a robust pneumatic system operating at 35 bar with multi-stage pressure reduction and compressed air cylinders to support the system against network pressure drops. A fully functional hydraulic system was implemented with three stages of filtration and continuous measurement of flow, pressure, and temperature using high-precision sensors from Bronkhorst and WIKA.

Leak testing is performed by an integrated ATEQ F620 tester. The test sequence is fully automated by a PLC, which is connected to and controlled by an operator via a custom LabView application. To ensure measurement integrity, a ‘unit dummy’ with test orifices was created to allow for easy validation of the hydraulic system. Operator safety is ensured through a sealed test chamber, safety controllers, and safety limit switches on the main access door.

Key achievements

High-degree of automation

The system fully automates the testing sequence, including valve rotation and changeovers between different product types, minimizing manual input.

Precision process control

Continuous measurement of flow, pressure, and temperature ensures highly accurate, reliable, and repeatable test conditions.

Integrated validation system

The custom-made ‘unit dummy’ allows for quick and reliable validation of the tester's measurement accuracy, fulfilling key client requirements.

Robust system design

The pneumatic system is stabilized against pressure drops, and the hydraulic system features advanced filtration and control for maximum reliability and uptime.

Safety-compliant engineering

The tester adheres to stringent safety standards with a fully enclosed test chamber and redundant safety systems, ensuring operator protection.