Powder valve
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Help! I bought a hard-sealed butterfly valve, thinking it would provide solid sealing, but when it arrived there was only one sealing ring on it! The sealing of the valve body and the valve disc is achieved through the seal ring on this valve disc! Because the medium is nanoscale powder, this seal ring becomes unusable after just a few uses! I spent a day in physical stores and found that some of them manufacture hard-sealed butterfly valves with a four-layer metal seal, with three layers of graphite in between! Does a hard-sealed butterfly valve of this kind count as one that involves direct contact? Is there really a hard-sealed butterfly valve that features true direct contact?
Yes, you can send me a private message. However, it’s not recommended to use a hard seal for powders, as it can lead to blockages. Soft seals are great; they provide a tight seal.
For hard-sealed butterfly valves in China, they all use the multi-layer structure of graphite and stainless steel as you mentioned. Domestic technology for direct competition in the field of pure metals is not advanced enough; even if sealing is possible, zero leakage cannot be achieved
For valves used on powders, it is recommended to use a dual-valve system for control; soft seals are acceptable. A pre-shut-off valve can be installed to prevent the powder from getting stuck, while the second valve is the one that actually provides sealing. Setting up a dual-valve system doesn’t increase costs much, and the requirements for the valves are significantly reduced.
http://bbs.hcbbs.com/thread-1320253-1-1.html
It’s a full head-on confrontation; some valve seats and sealing rings are welded with STL
You can take a look at Metso’s butterfly valves; their design features direct contact between the components. It uses a floating valve seat, and sealing is ensured through the difference in hardness of the metals.
For true head-on applications, a triple-eccentric butterfly valve is necessary. In the case of powdered materials, it is possible for the powder to press against the sealing surfaces at the moment the butterfly valve is closed; it is recommended that you try a hard-sealed ball valve instead
It seems no one is interested in this post; I’ll take care of it myself. It’s recommended to use a coaxial valve. In the case of a powder medium.