DISTANCE-LOCKING OF BELLOWS
Apart from the required nut and bolts for fitting, the bellows are supplied with two locking bolts. Each locking bolts have four non-slippery locking nuts of 1/4" size.
At the time of fitting, a bellow can be stretched / squeezed / bent with the help of locking bolts in order to make it suitable for particular position.
Once fitting of the unit is over, all the bellows should be locked in their fitted position. For that locking nuts should be gently rested on the bellow flanges from both the sides. This will prevent the bellow from unnecessary expansion / contraction / bending which could induce stress to the glass fitting.
In cases where bellow is attached to a agitated vessel which generate vibrations, bellows should not be locked completely in order to prevent the vibrations from transferring further. Instead they should be half-locked as follows :
a. In vacuum applications, locking nuts should be softly rested on the bellow flanges from the inner side so that bellow would not contract in vacuum. The other two nuts at outside should be kept 2mm away from the flanges.
b. In pressure applications, locking nuts should be softly rested on the bellow flanges from the outer side so that bellow would not expand in pressure. The other two nuts at inner side should be kept 2mm away from the flanges.
c. In atmospheric applications, all four locking nuts should be placed 2mm away from the bellow flanges. This will prevent the excessive expansion / contraction of bellow in case of accidental pressure / vacuum and will provide enough flexibility to prevent the vibrations from transferring further.