KF versus Sanitary

Curiosity question.

Sanitary junctions use a gasket, with a raised area that matches the grooves on the junctions.

KN junctions are completely flat and use a flat flange, that has a centering ring.

Both types use tri-clamps

I know that the KN types are used mostly with vacuum lines, while the sanitary types are used at ambient, vacuum and pressure.

Are KN types ok at pressure?

Does anyone use KN equipment for anything that is not vacuum related?

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The KF clamps I have used do not at all look safe for pressure- I think it’s a vacuum only system


Oops…thanks for the correction…KN…KF…what’s one letter among friends.

Obviously the title should read KF versus Sanitary…sorry

Yes KF are not rated for pressure above ambient. I’m not sure what pressure they can take in practice.

This one time I hooked the exhaust port on my pump up to my spd for a run.

The kfs held fine

I shot a stopper up and cracked it on the ceiling that day lol

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Oof. Yeah i have accidently blown out glass plugs on my wiped film before. From adding cleaning ethanol to the system without disconnecting the vacuum line first.

I know someone who did that on his VTA and cracked the body!!!

Could you imagine lol

I think dude got fired

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Working with glass wiped films gives me anxiety. We broke a glass body before (from overtightening flange). I was so happy when we went steel.

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You know what the replacement body cost?

I think it was like 10k for the VTA or something crazy like that

This was a chemtech and it wasn’t quite that much. I think it was 3500. Still a much more expensive piece of glass than i feel comfortable being my workhorse.

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If used with an over pressure ring, KF fittings are rated for pressure. KF10 100psi, pressure rating goes down as size of fitting goes up.