The plug inside a A105 Forged Lubricated Plug Valve has a cavity in the middle along its axis. You can see this in the image. Lubricant chamber at the bottom and the sealant injection fitting at the top ensure the supply of lubricant.

The small check valve below the injection fitting prevents the sealant from flowing in the reverse direction once the sealant is injected into the cavity.

Plug surface gets constantly lubricated by the sealant that moves from the center cavity through radial holes into lubricant grooves on the plug surface. Now why we required all this? Many plug valves are of all-metal construction.

The narrow gap around the plug may allow leakage, and if you reduce the gap further, it will increase the friction and plug may get stuck inside the valve body.

If you need Lubricated Plug Valve, you can contact us.