ABSTRACT
The most serious problem in mounting diaphragms is the introduction of spurious forces which may adversely affect the Performance of the diaphragm. These so-called mounting stresses may be of a mechanical or a thermal origin. If the diaphragm is not perfectly flat or parallel with the mounting base, unwanted forces are generated. In the design of any diaphragm Joint, attention should be given to proper location and fixity of the diaphragm during the welding process. Electron-beam welding done in a vacuum is especially useful in welding aneroid capsules, as evacuation of the capsule becomes automatic in welding. Laser-beam welding permits welding of metals in inert gas atmosphere rather than in a vacuum—an important advantage over the electron-beam welding. Intergranular corrosion is a phenomenon which occurs mainly with austenitic stainless steels when they are heated or cooled through the temperature range of about 800 to 1650°F.
