Complete refurbish of a leak tester that was releasing defective parts to a Japanese OEM line
The client operated a leak tester that had been modified multiple times over the years, with no documentation: unlabeled cabinet, impossible-to-trace wiring, improvised mechanisms with shims, indecipherable PLC logic. The machine was passing bad parts as good. That leak reached the Japanese OEM as a formal complaint. This was the first time Lübeck worked with this client.
The machine wasn't measuring anything, but it was reporting everything as good
Root cause: seal occlusion. The actuators were misaligned; upon closing, the seal blocked the inlet port before pressurization. The test equipment detected "zero leak" because air wasn't even entering the part. Test specification: 5 sccm at 150 kPa.
Scope constraint: the contract was refurbish, not fabrication. The client ended up auditing as if it were built from scratch, including components Lübeck never received in scope.
- Electrical wiring unlabeled and undocumented
- Pneumatic actuators misaligned relative to fixturing
- Occlusion failure: circuit wouldn't seal under test
- No operation manual or maintenance history
- Active complaint from Japanese OEM for defective parts released
- Electrical cabinet rebuilt from scratch, fully labeled
- Actuators realigned, fixturing reconstructed
- Dynamic occlusion test validated before sealing
- Operation and maintenance manual delivered
- Zero Japanese OEM complaints in +1 year of operation
Rebuilding from scratch was the fastest route with the lowest risk
Strategic decision: the option of doing a survey to preserve useful connections consumed time that wasn't available. The Lübeck team had been doing leak testing for years — rebuilding from scratch was faster and safer. Cabinet and control rebuilt in 1.5 weeks.
Forensic redesign of nests
Elimination of shims and improvised mechanisms. V-supports that ensure the tube's tangential position, ignoring non-critical dimensional variations of the part.
Dynamic occlusion test
Sequence added to the PLC: first the actuator seals the bracket leaving tubes unsealed; for 2 seconds the system validates that airflow exists. If no flow, the machine flags occlusion and stops before wasting time on an invalid test.
Electrical cabinet from scratch in 1.5 weeks
HMI programmed from scratch with intuitive flow. Cable combing, color coding, and labeling per IEC 60204-1 / NFPA 79.
Safe pneumatic logic
The original monostable valves caused actuators to return regardless of obstruction — an unsafe condition. Replaced with a configuration that prevents movement when the guard is interrupted. Safety curtains with SR716 relay, safety distance calculated per ISO 13849-1.
Zero complaints. Zero adjustments. Two more projects.
"The real problem wasn't the visible scrap: it was the parts that were actually scrap but that the previous machine passed as good — they reached the Japanese OEM and generated formal complaints."
— Portfolio documentation, case 02
We diagnose.
We don't guess.
If you have test or automation equipment you can't trust, we can diagnose it and give you a technical report before committing to a refurbish budget.