Triple offset butterfly valve manufacturer give some common lubricants used for butterfly valve shafts and discs .
Grease
Grease is a thick lubricant that provides long-lasting lubrication and corrosion protection. Common types used for butterfly valves include:
Lithium grease:Excellent for high/low temperatures. Resists water washout.
Lithium complex grease:Also suitable for a range of temperatures and pressures. Resistant to corrosion and oxidation.
Fluorinated grease:Provides lubrication even for molybdenum and other soft alloy surfaces. Good for high heat and pressures.
Oil
Mineral, synthetic or silicone oils can also work as lubricants for butterfly valves. Some examples include:
Mineral oil: Inexpensive, general purpose oil. Must be reapplied frequently due to evaporation.
Synthetic oil: Esters, polyalphaolefins (PAO), etc. Provide better high/low temperature performance and oxidation resistance than mineral oil.
Silicone oil: High temperature, chemically inert oil. Does not evaporate, even at high heat. Can withstand up to 600 F. Non-toxic and odorless.
Molybdenum disulfide (MoS2)
This is a dry powder lubricant that is applied to surfaces and compacted before use. It provides long-lasting lubrication at high heat/pressure and resists wear/corrosion. Often used on molybdenum shafts. requires reapplication for heavily loaded valves.
Wax
Paraffin, beeswax and microcrystalline waxes can coat surfaces to prevent corrosion. They melt at surface temperature, providing a lubricating film. More brittle than oils/greases at lower temperatures. Essential to re-apply after valve maintenance.
Grease-impregnated PTFE tape
PTFE tape with a lithium-based grease embedded provides lubrication while sealing threads. It can prevent galling and ensure valve closure tightness. Easily reapplied. Works for a range of temperatures and pressures.