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Newstan was the winner earlier this year of the NSW Minerals Council Health and Safety Innovation Award for its purpose-built Centennial Hydraulic Control System (CHICS). The system limits worker exposure to the failure of high-pressure fluid system components.

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The Newstan team was driven to design the system after an incident at the mine when there was unintentional repressurisation of a hydraulic system after it had been isolated and dissipated. Employees were exposed to the potential for a high-pressure injection injury.

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This was all in spite of the hydraulic system being isolated correctly, in accordance with Newstan’s Isolation Procedures.

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The incident led to an investigation by the mine and the Department of Primary Industries which found the root cause of the incident was the failure of the seals in a 40mm ball valve.

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The seals were found to be eroded by the hydraulic fluid flowing across the seals at high velocities. This occurs when the valve is partially open, or “throttled” – a procedure typically used when restoring pressure to the circuit to avoid “shock loading” to components.

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It was decided that the best way to tackle the risk was through engineering controls.

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With this in mind, the Newstan team – together with information and help from APT Training, a mine safety officer and the occupational health and safety committee – designed a new system which allows the isolation and restoration of pressure with a sequenced key system; pressure to be re-applied to the system at a controlled rate; dissipation of pressure at the isolation points; and visual verification of the isolation procedure all at one point.

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This system can be installed as stand-alone unit or in multiples to establish a common board for complete area isolation of incoming supply. The system uses a bypass metering system to slowly introduce pressure to the hydraulic circuit during restoration.

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This will reduce high-pressure transient spikes that fatigue hoses and components; prevent operators from metering flow with the ball valve during restoration, an operation which resulted in high-velocity fluid-eroding valve seals; and increase the reliability of the valve system and reduce maintenance costs.

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The system also combines all isolation valves and components required, reducing the complexity and likelihood of physical damage.

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“This innovation is an important and timely innovation for control of high-pressure hydraulic systems and represents a very significant safety improvement,” Centennial Northern Operations general manager Steve Bracken said.

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“The transferability of this innovation to other longwall mining operations and industries which use hydraulic power will provide significant safety benefits.”

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Centennial Coal holds the intellectual right to the design. A complete valve with Fortress Locks costs about $30,000.