Expansion Bellows.
From the photo`s you can see examples of a correctly fitted bellows and a bellows which is incorrectly fitted. It is obvious from the incorrectly fitted bellows that no allowance was provided for the expansion of the steam line, whereas with the other bellows enough allowance was made for the expansion. Remember when fitting the bellows, a steam line expands at approximately 2mm for every meter of piping. Sufficient anchor points should be provided so that the piping does not push the building or any brackets on which it is resting. The steam piping must be able to move on its supports either by means of hanging brackets or on rollers or as illustrated with slide brackets which allows the piping to expand along its length while preventing it from moving either up or towards the side.