Quick question, when using the stainless steel clamps between two kf25 ports, how tight should I twist it down? should I use a wrench and really tighten it down all the way, or should I just tighten it until I can no longer turn it with my hands?
Thanks for any input
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Personal opinion; hand tight, then quarter or half turn more with a tool.
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Another question, should the gaskets be greased every time? Definitely grease em every now and then to keep the gasket material “hydrated”, but is it essential for the best vacuum performance?
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You should allow vacuum to seal it up and go one turn past that. Never tighten them down all the way. This ruins and deforms the seal and causes leaks. Kf fitting will create a 1 micron seal without even needing to tighten them. The wingnut is for safety and assembly. It has nothing to do with seal. You should just go one or two turns past touching. And you’ll be fine.
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No, do not grease. Kf is a dry seal down to 5-8 scale depending who made it. Grease will only cause leaks and make the seal elaster out of position and warp.
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If you are using tools, your misusing kf fittings.
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Along this line, should gl gaskets be greased?
As in gl14/gl18. It depends. We used to grease them bc we didn’t know better - but in my opinion no absolutely not. They are a dry seal. We make our own gl fitting now and they are so high quality they have a sealing device in them.
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Is using grease dependent on gasket material? I find most gaskets used with KF are viton, what about another material?
A proper connection like this should avoid grease. It will allow the material to become slippery and slide out of position and sealing nature. Especially becausee with grease you can apply more surface pressure and movement.
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