DN>=50 valve, stem and bracket between the use of lubricated bearings, and stem exposed part should be dust-proof measures to prevent atmospheric corrosion. TwentyDoes it mean that all DN>=50 valves, valves and supports must be lubricated with bearings, or that only the bearings are used between the valve stem and the bearings?
All need dust protection measures, long time, in order to prevent the garbage things adhesion
When the utility model is used, a thin layer of grease is applied on the exposed part of the valve stem, so that lubrication can not only be played in operation, but also can prevent the exposed part of corrosion.
Apply a thin layer of grease can be on the exposed parts of general use, mainly to prevent locking or switch between the valve stem packing for a long time due to friction is not in place, but also to lubrication and corrosion of the
