Double cone closures

Double Cone/Fluor Double Cone 20,000 12-36 Gasket Matl Depends on configuration Lapping of groove required Use with either threaded or flanged closure... 

Like most high pressure joints, the double cone requires precision machined surfaces. In addition, proper bolt loads and tightening procedures are critical. Double cone gaskets can be used with either a bolted flat head or threaded closure type configuration. 

Figure 8-10. Threaded closure with double cone gasket...

From a design standpoint, the total hydrostatic end force, H, is taken by the threads in a threaded closure, or by the studs in other designs. Various types of gaskets can be used with either design but all are the self-sealing type such as Bridgman, delta or double cone. 

Figure 8.10 Flanged closure 1, screwbolt 2, extensometer 3, nut 4, washer 5, flange 6, doubled cone gasket 7, closure.

A final complication is the fact that closure systems (particularly those which assist in the dispensing or administration of a product) are becoming more complex and more sophisticated. The list which follows indicates many of the various closures and closure systems which are available for both primary and secondary packs as seals or closures can be temporary or permanent, certain packs may have a series of closures created by the way in which they are converted or manufactured. A tinplate built-up aerosol container, for example, has four permanent seals, i.e. welded or soldered side seam, a cone and a dome held to the container body by double seams, a swaged-in valve cup, and an operational valve system (the in-use closure). Some of the systems will therefore be described in further detail. 

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