Frequent loosening of nuts caused by system vibration - becomes a Reliability issue

  

Checks points to prevent loosening of nuts/ bolts:

1. Ensure nuts don't have appreciable lateral play on bolts. This could be judged by visual inspection.

2. Nuts should sit on perfect flat surface .Avoid point or line contact between nuts and seating surface.

3. In case seating surface is not machined face, use of spring washers beneath the nuts can help.

4. In case spring washers cannot accommodate on seating surface because of increased size of bolt hole dia, place suitably machined flat washers on seating surface and then place spring washers on top of it beneath the nuts..