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Read MoreValve packing is a sealing element installed between the valve stem and the stuffing box, preventing media leakage from the valve's moving parts. As a critical sealing component, the packing material's performance directly affects the valve's sealing performance, reliability, and service life.
Key Points for Valve Packing Installation and Maintenance
Installation Specifications
Clean the stuffing box and remove any remaining packing residue
Use staggered cuts (30° to 45° angle) for installation
Tighten layer by layer, maintaining a torque of 5 to 15 N·m
Perform 3 to 5 heat tightening cycles (for high-temperature valves)
Maintenance
Regularly check the gland bolt preload
Observe for leakage (allowable dripping of ≤ 1 drop/minute)
Add lubricant (graphite-based grease)
Replacement interval: Generally 2 to 5 years (depending on operating conditions)
Functions of Valve Packing
1. Sealing
Prevents media leakage: Forms a dynamic sealing barrier between the valve stem and the stuffing box, preventing pipeline media (liquid, gas, or steam) from leaking along the valve stem's axis.
2. Auxiliary functions
(1) Lubrication protection
Self-lubricating materials such as graphite/molybdenum disulfide can reduce the friction coefficient of the valve stem (0.08~0.15)
Reduce valve stem wear and extend service life (increase by 2~3 times)
(2) Adaptability to working conditions
Temperature buffer: Graphite packing can withstand drastic temperature differences from -200℃ to 600℃
Pressure regulation: Metal spiral wound gaskets can withstand 42MPa high pressure impact
Corrosion protection: PTFE packing resists strong acid and alkali corrosion (such as 98% sulfuric acid)
(3) Emergency safety function
Fire-safe packing (such as graphite metal composite) expands at high temperatures to form a secondary seal
Complies with API 607 fire test standards