What needed solving
Operators had to read painted weights and date codes, then enter the values into the filling system. Worn paint, grime, reflections and cylinder rotation made the task difficult.
How Qualitas solved it
A camera and controlled lighting capture the cylinder markings. Qualitas vision software reads the tare weight and DPT code and supplies the results to the OEM’s filling-line system. Cylinders overdue for pressure testing are rejected from filling.
The markings that control the filling decision
| Field | What it tells the filling line |
|---|---|
| Tare weight | The empty cylinder’s weight, used in the filling process. |
| DPT code | When the cylinder is due for pressure testing. An overdue code triggers rejection from filling. |
DPT means Due for Pressure Testing. The letter identifies the quarter: A ends in March, B in June, C in September and D in December. The following digits identify the year. B26 means testing is due by the end of June 2026; it is a testing-due code, not the cylinder’s physical-life expiry date.
Reading worn and reflective markings
- The camera captures the cylinder’s upper markings under controlled illumination.
- Vision software locates the painted characters and reads them using optical character recognition (OCR). Repeated markings provide additional readings to compare.
- Tare-weight and DPT results feed the filling-line workflow. Cap presence/absence inspection supports the relevant line-stage checks.
The project scope excludes cylinder dents, scratches and other body defects. Completely masked or wiped-out characters cannot be reliably read.
An OEM partnership with production scale
Qualitas supplied the vision camera and lens, character-reading software and operator interface. HT Process Controls handled material movement, mounting, the industrial computer and PLC integration. The system supports IndianOil cylinder-filling operations.
| Outcome | Result |
|---|---|
| Deployment scale | 150 deployments. |
| Filling-line throughput | A filling line increased throughput from 12 to 40 cylinders per minute. |
| Filling eligibility | Cylinders overdue for pressure testing are rejected from filling. |
Hear from HT Process Controls
Sailesh Gupta of HT Process Controls describes the partnership and its impact on cylinder-filling automation.
Share your cylinder variants, marking samples, line rate and PLC interface. We can scope tare-weight reading, DPT validation and cap checks with your filling-equipment team.
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