Quality / Service Technical Reference
3-Way Valve Difficult to Open - AJYA90LALH / AOTA90LALT
Commissioning report - valve found excessively tight
A quality assurance problem report identified an instance where the 3-way valve was excessively tight during commissioning on the affected outdoor units listed below.
Affected Units
| Model | Serial Number | Manufacture Date |
|---|---|---|
| AJYA90LALH | R303292 | 17 July 2014 |
| AOTA90LALT | R102250 | 7 July 2014 |
Both units were manufactured on Outdoor Unit B Line.
Reported Problem
During commissioning, the 3-way valve was found to be too tight.
Factory Investigation
- The 3-way valve is tightened after heat-run testing.
- The heat-run testing standard specifies a tightening torque of 10 N·m for the liquid valve.
- Workers use a torque wrench when tightening the 3-way valve.
- The factory manufacturing process records for the affected units showed no abnormality.
Factory Stock Survey
A survey of factory stock found no similar problem.
Investigation Conclusion
The factory investigation was unable to reproduce or identify a manufacturing-process issue that would explain the reported tight valve.
FGL considered that there may have been adhesion at the valve joining surface. One possible explanation was surface unevenness causing the mating surfaces to adhere; however, this was only a hypothesis and was not confirmed by the investigation.
Finding: No confirmed root cause was established. The issue was to remain under observation, with further analysis to be carried out if another sample became available.
Service Guidance
- If a 3-way valve is unusually difficult to operate during commissioning, do not assume excessive factory tightening is the confirmed cause.
- Confirm the valve condition before applying excessive force.
- Inspect the valve and surrounding pipework for signs of damage or abnormality.
- If the valve cannot be operated normally, record the model and serial number and escalate the case for technical review.
- Where possible, retain the affected component or unit for further analysis.
Information to Collect if the Issue Reoccurs
| Item | Details Required |
|---|---|
| Unit identification | Full model and serial number |
| Valve | Which valve is affected and whether it can be moved at all |
| Commissioning stage | When the issue was identified |
| Evidence | Photos of valve, cap, stem and surrounding pipework |
| Component retention | Retain the valve/unit for analysis where practical |
Important: The original investigation did not establish a confirmed manufacturing defect or root cause. Any recurrence should be documented and assessed on its own evidence.