Selflocking of spring hangers

[thermmech]

In our plant we had number of cases where spring hanger locking nuts have moved into "locked position" due to piping vibration - nuts tend to slide down. That resulted in spring hanger casing damages and temporarily increased piping loads. To minimize such occurrences I'm thinking we could replace existing *plain nuts* with those with plastic inserts.

Does anyone have an opinion on the effectiveness of the proposed or an alternate suggestion? Would appreciate some help for this practical issue.