ABSTRACT
Bellows are the most flexible of all pressure-summing devices. Bellows of extremely low range and size can be produced by the electrodeposition method where a thin film of metal is electrode-posited on a mandrel which is then removed by melting it away from the bellows. The basic assumption is made that the bellows consist of a number of diaphragms mounted in series and rigidly joined to each other. An advantage for welded bellows is the larger number of convolutions per unit length that may be incorporated in the bellows. Bellows for volume compensation are commonly used in oil-filled devices such as gyros, accelerometers, and other floated instruments. The linearity of bellows depends on the linearity of the individual bellows element. Ideally, the bellows should be capable of compensating through the full temperature range and maintaining a positive pressure on the fluid at all times, as voids or "cavitation" could be very troublesome.
