What type of packing is most commonly used on globe valves?

Globe valves commonly use Teflon string packing due to its excellent properties that suit the valve's operational requirements. Teflon, or polytetrafluoroethylene (PTFE), is known for its exceptional chemical resistance, low friction, and high-temperature tolerance. These characteristics make it ideal for sealing applications in globe valves, which are frequently subjected to a range of fluids and pressures.

The use of Teflon string packing helps ensure a reliable seal at the valve stem, preventing leaks while allowing smooth operation. Its resilience against common chemicals and its ability to maintain performance over time contribute significantly to the longevity and efficiency of the valve.

While other packing materials like nylon or graphite string have their applications, they may not provide the same level of performance or compatibility with various chemical processes typically associated with globe valves. Viton is similarly effective but is generally chosen for specific scenarios that demand its unique properties, such as high-temperature environments. Thus, Teflon string packing is the preferred option for globe valves in many setups due to its versatile benefits.