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Supagraf® LF Rings - for valves

Description
Supagraf^® LF Rings represent a major enhancement of the operational capabilities of graphite sealing rings used on valve stems. 

The rings are precision moulded from high purity expanded grahite foil to which a special low friction coating has been sinter bonded. This 5μm thick coating is sinter bonded to the expanded graphite before the moulding process to ensure maximum service life.

Typical applications

• Valves where fugitive emission control to 50ppm or less is required.
• Valves that handle dry gases and other fluids, where friction on standard graphite seals is unacceptably high.
• Valves that suffer judder, hesitation or erratic action due to carbon pick-up or high-spot friction on the spindle.

Prime features

• Greatly reduce the torque needed for efficient valve action.
• Save on power consumption and enable smaller actuators to be used.
• Lower the break-out friction for smoother valve operation.
• Retain exceptionally low friction characteristics with fugitive emission control for up to 20,000 valve cycles.
• Subsequent manual adjustment extends performance to 60,000 cycles.
• Fire-safe capability enables rings to be used in plant subjected to fire rating tests.
• Can be supplied live-loaded.

Chemical properties
Chemically inert to most media in the range pH 0-14.

Service capabilities - valve stem duties
Maximum operating temperature:  +350°C.
Minimum operating temperature:   -200°C.
Maximum system pressure:            250bar.

Low friction capabilities
See pdf file offered below for details of test results and graphs.

How supplied
Precision moulded rings in endless form or with single split or matched scarf-split halves. Sections 1.5mm to 40mm; diameters 2mm ID to 1100mm ID.

Click here to download the Compression Packing Guide pdf (2.17MB)      

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