How a maintenance overhaul prevented 280 hours of downtime

Every three years, the ZH compressor at the Solvay hydrogen peroxide factory in Póvoa de Santa Iria, Portugal, has to be powered down and given a maintenance overhaul.
But while the critical ZH compressor is silent, production grinds to a halt. So when the company heard it needed an overhaul that would require it to be out of service for three weeks, Atlas Copco and Solvay technicians developed a plan to complete the maintenance project in just nine days of intense work.

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Overhauling ZH within nine days instead of 3 weeks

As part of its preventive maintenance contract, the 10-year-old ZH compressor at the Solvay facility has a major overhaul every 24,000 hours, ie every 3 years.


Equipped to save energy and guarantee reliability, the compressor must undergo regular preventative maintenance – and this time the compressor needed to have its rotors balanced. Under normal circumstances, this would take three weeks but, because the ZH compressor plays such a fundamental part in the production process, the company could not afford it to take so long.

“Thanks to Atlas Copco’s flexibility and cooperation, and their awareness of the impact this compressor’s absence would have on us, we managed to put together a work plan that allowed us to overhaul the compressor in record time.”

Ramiro Dionísio, Head of the project at Solvay

No room for error

In order to complete the overhaul in 9 days, there was no room for error. On the first day of work, shortly after the rotors were removed, an international carrier was waiting at the gates to take them to Germany for balancing.

“Nobody does this balancing work in Portugal, so the parts have to go directly to the manufacturer,” says Ramiro Dionísio.

24 hours later, the rotors arrived in Germany, and within 3 days the work was completed and the rotors returned to Solvay.

A team of two Atlas Copco technicians and two Solvay employees then reassembled the equipment.

“The entire overhaul was completed in nine days. The tenth day was spent monitoring the machine as it went back into production,” Dionísio says. “Let’s hope it lasts at least another 80,000 hours”.