Demanding requirements in a dangerous environment
In burner management systems, extraordinary reliability is expected from the on-off and safety valves, as unnecessary shutdowns of a heater would cost hundreds of thousands of dollars on a daily basis. In hazardous cases especially, the safety shut-off valves must close under all circumstances. In addition to shut-off safety, the on-off valves in front of the burners are responsible for managing the correct heat temperature. This means that reliable switching is very important, as it reduces operational costs and increases the heater efficiency.
The refinery’s emphasis on complying with and even exceeding the standards for tightness and safety established by the European health, safety and environmental (HSE) regulations made its valve selection task even more difficult. The company also expected that the chosen valves should be able to perform like new over a long period of time. As shutdowns for inspection and maintenance are costly, regular shutdowns are normally scheduled only once every four years, and they need to be performed as quickly as possible to minimize downtime.
Moreover, to protect the health of the operators and the environment, the best possible valve sealing over its full operational lifetime was required to avoid fugitive emissions of hazardous and toxic fuel gases.
OMV Petrom S.A. chose Jamesbury™ Series valves for its fuel gas safety shutdown and burner on-off applications. These soft-seated 7000 and 9000 ball valves are made for highly demanding uses such as fuel line emergency shut-off and switching applications.
The valves’ seating design and material provide superior long-term bubble tightness that withstands a high number of thermal cycles and valve strokes, even exceeding the 250,000 strokes required by EN 161, which is the standard for automatic shut-off valves in gas applications. Additionally, the cavity relief feature enables safe operation, even in the event of sudden temperature increases. This allows any fuel gas overpressure that might build up in the ball valves’ cavities to be released automatically on the upstream side.
Moreover, the shaft sealing design ensures the highest level of reliability and safety while achieving the lowest possible operational costs. The ball valve series is certified according to the most relevant fugitive emission standards, such as TA-Luft/VDI 2440 and ISO 15848-1 BH.
To fulfill European directives, the refinery followed EN 746-1, the standard for safety requirements in combustion and fuel handling systems, which requires that only EN 161-certified valves can be used in burner management systems. These shut-off valve units are approved by TÜV Rheinland according to EN 161 Class A and certified according to IEC 61508 SIL 3. The approvals include the intelligent safety solenoid with partial stroke testing and diagnostic features that provide additional safety and predictive maintenance capabilities.
Stabilized costs and shorter downtime
Since the refinery had all relevant certificates for the fuel gas shut-off valves and therefore fully complied with European regulations, the on-site approval process was accelerated.
High process stability and safe operation in the refinery have been achieved through the unique design of these valves created specifically for burner applications. In turn, this has ensured that the operational targets of the process heaters are met according to the planned shutdown schedule.
The simple and maintenance-friendly design of the burner valves has reduced operational costs and shortened downtime in the refinery. Additionally, full support has made the implementation of the new valves a smooth process.
This blog post has been up-dated in July 2020, due to company name change to Neles.