CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application under 35 U.S.C. § 371 of International Application No. PCT/DE2017/000411 filed on Dec. 2, 2017, and claims benefit to German Patent Application No. DE 10 2016 015 190.0 filed on Dec. 21, 2016. The International Application was published in German on Jun. 28, 2018 as WO 2018/113808 A1 under PCT Article 21(2).

FIELD

The invention relates to a mounting device for a flat seal of a flange connection.

BACKGROUND

CF flanges are described in ISO 3669 at the nominal widths of DN 16 to DN 250, and in more detail in ISO/TS 3669-2 at the nominal widths of DN 10 to DN 400.

CF flanges are based inter alia on the CONFLAT flanges by the company Varian. CF flanges are used for connections of ultra high vacuum (UHV) components; the flanges themselves are comprised of stainless steel, the sealing material is usually copper.

A CF connection consists of two symmetrical flanges with cutting edges; a metal flat seal which is centered in a flat undercut, or a turned groove, or a channel of the CF flange; and a sufficient number of screws which ensure the necessary high contact pressure. In addition to fixed flanges which are each to be aligned around a hole position, there are rotatable collar flanges so that the flanges can be oriented arbitrarily about their major axis.

To produce an ultra high vacuum (UHV), special requirements are to be placed on materials and connections. The CF standard ISO/TS 3669-2:2007 has been established for this purpose in UHV engineering. The CF flanges are made from stainless steel circular blanks on CNC lathes. The flanges are normally divided into two parts and consist of an inner part with the sealing surface and an outer part with the screw holes. The flanges have the groove for receiving the seal on the vacuum side, and a cutting edge as a sealing surface. Because of the low leakage rate and high bakeability required in UHV engineering, the sealing of the CF flanges takes place via a flat seal made of oxygen-free (OFHC) copper. This generally can be used only once due to the plastic deformation by the cutting edges. The contact pressure, for example, is generated by the screws which are tightened without distortion.

During assembly, the cutting edges of the flanges press into the enclosed sealing disk and deform it. What is known as extrusion takes place on the outer cutting flanks; the cutting process takes place at the same time on the inner side. Creeping is limited by the outer vertical flange walls so that very high pressures occur in the boundary layer. Under the high pressure, the copper conforms to the microstructure of the cutting edges and fills smaller surface defects, thereby producing a metallic ultra high vacuum-tight connection.

QCF components and the associated VaCFix® tension chains are a product design of VACOM. They have conical tightening surfaces and combine the sealing principle of the ConFlat® flange (cutting edges according to ISO/TS 3669-2) with a simple assembly via what is known as a chain lock. The QCF components can be assembled faster, more easily, and at the same time in a more space-saving manner, and are normally connectable by means of adapters to all existing vacuum systems. The CF-QCF adapters allow the user to use the QCF connection technique on existing UHV systems, and thus to work flexibly as well as independently of suppliers. The advantage of the QCF technology lies in the shorter assembly time, by up to 75%.

(Q)CF flange connections have a low leakage rate of <1.0E-11 mbar I/s and are bakeable. CF flanges are available in a size from DN 10 to DN 400, QCF flanges in a size from DN 16 to DN 100.

Different kits and flange connections are available from different suppliers. Rotatable or fixed flange connections with and without pipe socket, reducers, T-pieces and crosspieces, and a variety of other components are marketed for CF flanges.

SUMMARY

In an embodiment, the present invention provides a mounting device for a flat seal of a flange connection. The flange connection includes a first flange, a second flange, and a flat seal arranged between the flanges. The mounting device includes a clamping jaw for a clearance between the first flange and the second flange. The clamping jaw tapers at an end to a nose for holding the flat seal.

