Control valve maintenance
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What lubricant should be used to maintain the dynamic seal between the valve stem and the packing of a control valve? Thanks!
Butter; it’s better to use aviation oil if possible.
Generally, no lubricant is added; the improvement effect of adding a lubricant on the filler is not significant, and in some cases, contact with the medium or an inappropriate choice of lubricant can lead to accelerated aging and damage of the filler. Under high-temperature conditions, there are hardly any lubricants that can be used; ordinary lubricants or butter will cause carbon deposits to form, leading to valve sticking and damage to the valve stem!
Generally, no lubricant is added. If the valve operation is hindered due to friction in the valve stem, simply press the packing gland a bit, or replace the graphite packing. 、
Lubricating grease is generally not applied on the side of the filler; lithium-based grease should be applied to the cylinder side. A little lithium-based grease can also be applied to the bolts and fasteners to prevent rusting. If the valve is a bit stuck, you can loosen the packing; however, it’s also fine to apply some glycerin at the stem packing area. I’ve seen factories use glycerin, and the control valves worked well as a result.
Glycerin is generally used in factories, but I don’t think it works; after a few days, the area becomes completely dark
If you wish, just apply some yellow glycerin.