Nut in a flanged joint, by rubbing against the surface of the flange, creates a groove which, depending on its depth, affects the relation between tightening torque and tension on the stud. This phenomenon is more pronounced on small bolts.
Washers – FM Tech. Solution
Protect flange surfaces from the friction act of the nuts
By increasing the size of the bolts this phenomenon is less common, however, the use of washers is recommended as a very effective measure.
According to ASME PCC-1, the use of washers improves the transmission of the load on the studs.
Use of washers
Washers protect the surfaces of the flanges from the friction actions of the rotating nuts; reducing, even in the case of bolt tensioning, the relaxation phenomena due to the locking of the nut on the surface of the flanges.
Avoiding that local deformation, on the flange surface, increases with time.
Using washers with the proper outer diameter and thickness will reduce the specific pressure on the flange.
This will minimize the effects of locking and seizure between nut and flange surface, and in particular in case of high temperatures.
Do you know that..
- VED, in accordance with ASME PPC-1 ed. 2019, designs and manufactures “Washers-FM” with geometric and mechanical characteristics that greatly improve the reliability of the flanged joints.