The use of O-Rings in vacuum seal applications differs with respect to the usual uses, for the dimensions and the finishing of the housing that holds the ring.
Actually, to guarantee the air vacuum seal, the housings must have dimensions such that it allows the O-Ring to occupy almost the entire available space (figure 1); in this way, all of the housing surfaces become seal surfaces and therefore their finishing must be very accurate. Finally, to guarantee a good seal effect it is recommended using compounds containing a low penetration coefficient to gases and a low Compression Set, particularly important in relation to the flattening that the O-Ring undergoes from more sides. To reduce the penetration to the gases, and the loss of weight of the compounds in vacuum presence linked to the liberation of the most volatile loads, particular lubricants can be used. For any further related queries, we ask you kindly to contact our technical department