Case Study: Medical-Grade Fluid Pathway Tubing — Sub-SCCM Leak Detection at Production Speed
Industry: Medical Devices | Hardware: LD Series Differential-Pressure Leak Tester + LT-D01 Inner-Expansion Quick Connector
| Specification | Value |
|---|---|
| Test Pressure Range | 95–500 kPa |
| Equivalent Test Volume | 40 mL |
| Leak Rate Limit | < 3 SCCM |
| Pressure Decay Limit | < 0.2 kPa·min⁻¹ |
| Cycle Breakdown | Charge 15 s / Stabilize 30 s / Measure 60 s / Exhaust 2 s |
| Total Cycle Time | 107 s |
| Detection Method | Differential pressure (reference-volume bridge) |
Problem
Infusion sets and fluid-transfer connectors represent a Class II sterile-barrier application: a leak rate exceeding 3 SCCM at a test volume of only 40 mL constitutes a patient safety risk. Direct-pressure testers lack the resolution to detect this threshold reliably — at 40 mL, a 3 SCCM leak produces a pressure decay of approximately 0.1 kPa over 30 seconds, below the noise floor of standard pressure transducers.
Solution
The LD Series differential-pressure tester compares the DUT against a hermetically sealed reference chamber of identical volume. The bridge-measurement architecture cancels common-mode pressure disturbances — ambient temperature variation, barometric drift, building HVAC cycling — allowing detection of pressure differentials as small as 0.01 kPa. This is an order of magnitude more sensitive than direct-pressure methods at equivalent test volumes. The LT-D01 inner-expansion connector seals the flexible tubing bore (Φ9.5–Φ24.4 mm) without compressing the outer wall, preserving the tubing geometry during test.
Result
- 3 SCCM leak rate limit reliably detected at 40 mL equivalent volume
- 0.2 kPa·min⁻¹ pressure-decay acceptance criterion maintained across 8-hour production shifts
- 107-second cycle meets throughput requirements for Class II medical device production
- Measurement traceability compliant with ISO 11135 sterile barrier integrity validation requirements