Sealing type and material selection for the axial movement of the valve shaft
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Our company has a type of valve in which a cylinder is used to drive the valve stem to move axially in order to open and close it; it operates at a very high frequency, performing more than 2,000 operations per day； Currently, a standard valve with PTFE V-ring gaskets is being used; the seal wears out after a short period of time. Since the material reacts and crystallizes very easily when exposed to air, the leaked material often causes the valve stem to freeze due to the material present, preventing it from moving. I would like to ask the experts here: are there any better sealing methods or sealing materials?
Is it linear stroke or rotary stroke?
It’s best to keep the structure diagram; it’s said that this question cannot be answered. Can metal wound gaskets be used? For non-metallic materials, PEEK could be tried; it is much more wear-resistant than ordinary PTFE
Linear stroke, different from the spiral upward and downward movement of ordinary valves
The structure is the same as that of a regular valve’s packing seal; the difference is that the valve stem is driven by a cylinder to move axially, that is, it is pulled out and inserted； Valves achieve their function through the rotation of the valve stem ； Do you mean using PEEK material for the gasket?
If the operating temperature is not high, I recommend using fluororubber O-rings as seals. The O-rings available on the market are generally designed for static sealing, while what you need here is a seal suitable for dynamic sealing. Additionally, the valve stem should be treated to have a mirror-like surface, which will help increase its service life. I work in the Chengdu market and deal with programmable valves on a frequency similar to yours. They require a switching frequency of 1 million times per year