Stadco: from weekly valve failures to two years without a single one
Stadco's hydraulic presses had at least one valve failure a week, and each replacement took up to three days of work. Two years after offline filtration was installed, there has not been a single valve-related failure.
ISO 4406 cleanliness code
Stadco stamps steel and aluminium body parts for the automotive industry, and the plant’s hydraulic presses run around the clock. The presses had valve failures at least once a week. Each valve costs around £20,000, and a replacement could take up to three days of maintenance work.
Oil analyses showed critical particle contamination and a high varnish level (MPC to ASTM D7843). Much of the contamination had settled at the bottom of the tanks. A full system flush was not possible, because the presses could not be taken out of service for that long, and two earlier attempts with other filtration solutions had not solved the problem.
Delta Xero cartridge units were installed across the plant, one to four cartridges per machine depending on oil volume. The oil gradually worked its way through the system as a cleaning agent, and after 12 months the tanks and components were clean. Today only the cartridges are changed, typically every 8 to 12 months, and full oil changes are no longer necessary.
Two oil analyses from an independent laboratory (Polaris Laboratories), taken six weeks apart, show the improvement in figures: the cleanliness code fell from ISO 19/17/12 to 14/12/09, and the MPC value from 45.9 to 3.5. Two years have now passed since installation without a single valve-related failure.
The figures before and after
| Measurement | Before | After |
|---|---|---|
| ISO 4406 cleanliness code | 19/17/12 | 14/12/09 |
| Particles above 4 µm per ml | 2,644 | 133 |
| Particles above 6 µm per ml | 975 | 35 |
| Particles above 14 µm per ml | 26 | 4 |
| MPC (varnish potential) | 45.9 | 3.5 |
| Valve failures | at least one a week | 0 in two years |
“The customer is extremely happy. When swapping out the old cartridges with the new, improved Delta-Xero cartridge there were signs, proved with independent oil sample reports, that the new cartridge performed significantly better than the old units. The oil cleanliness was cleaned to a better level and not only that, it achieved this quicker as well.”