Helium leak testing pressurized parts often goes hand in hand with pressure proof testing. Many products must withstand high internal pressures while also maintaining leak-tight integrity. Manufacturers commonly perform both tests during production to ensure safety, compliance, and long-term performance.
This article explains how engineers combine helium leak testing pressurized parts with gas pressure proof testing in a safe and production-ready process.
Why Helium Leak Testing Pressurized Parts Requires Proof Testing
Some products, such as refrigeration compressors, heat exchangers, and pressure vessels, must pass a pressure proof test in addition to a leak test. For example:
- UL 207 requires proof testing for refrigeration-containing components
- The ASME Boiler and Pressure Vessel Code allows optional gas pressure proof testing as an alternative to hydrostatic testing
Engineers often use dry compressed air or nitrogen for proof testing. Because gas stores significant energy, teams must apply strict safety controls during pressurization.
Integrating Proof Testing with Helium Leak Testing Pressurized Parts
Manufacturers can perform proof testing and helium leak testing pressurized parts on the same system. This approach reduces handling, shortens cycle time, and improves process consistency.
- A typical integrated process includes:
- Gas pressure proof testing
- Gross leak screening
- Helium charging for leak detection
- Optional helium evacuation and recovery
- Optional nitrogen back-fill
This sequence supports both safety validation and leak integrity verification.
Helium Sniffing for Pressurized Parts
Helium sniffing works well for large pressurized parts with leak rate limits near 1 × 10⁻⁵ atm·cc/sec or higher. In this method, operators pressurize the part with helium and scan potential leak points using a probe.
To support consistent results, manufacturers often use a dedicated helium charge station. This station controls pressure, purges residual gases, and prepares the part for sniffing.
Helium sniffing offers flexibility, especially when full-chamber testing is impractical.
Safety Considerations for Helium Leak Testing Pressurized Parts
Because proof testing uses high gas pressure, safety must drive system design. Engineers commonly add:
- Safety interlocks that verify doors or shields are closed
- Pressure relief mechanisms
- Controlled venting sequences
When manufacturers use vacuum chambers for leak testing pressurized parts, they must also plan for worst-case failures. Thick chamber walls, protective cladding, or isolated test rooms help protect personnel from pressure release or shrapnel.
Helium Leak Testing Methods for Pressurized Parts
Engineers select the leak test method based on part size, leak rate requirement, and production flow.
Common methods include:
- Helium Sniffing
Manual detection of helium escaping from a pressurized part - Helium Accumulation
Automated capture and measurement of helium inside an enclosure - Helium HATS™
A patented hybrid accumulation method using partial vacuum - Helium Vacuum
Full-vacuum testing with helium applied across the pressure boundary
Each method supports helium leak testing pressurized parts at different sensitivity and throughput levels.
Equipment for Helium Leak Testing Pressurized Parts
LACO Technologies engineers custom systems to integrate pressure proof testing with helium leak detection. These solutions include:
- Automated hard-vacuum leak testing systems
- Custom vacuum chambers
- TITAN VERSA helium leak detectors
- Integrated safety and control systems
Summary: Reliable Helium Leak Testing Pressurized Parts
Leak testing pressurized parts becomes more effective when engineers integrate proof testing into the leak test process. With proper system design, manufacturers can safely validate structural integrity and detect leaks using the same equipment.
By combining safety controls, appropriate test methods, and helium detection, production teams achieve reliable results while meeting regulatory and performance requirements.
