Patent ID: 9551429
Date: 2017-01-24
CPC Classifications: F16K

Claim:
1. An over-pressure relief device comprising: a reverse-acting rupture disc including a central bulged section having a concave face and a convex face, and an outer flange section in surrounding relationship to said bulged section, said bulged section including a laser-defined reversal initiation feature that controls the pressure to which said rupture disc must be exposed in order to initiate reversal of the concavity of said bulged section and defines a location on said bulged section at which reversal of the concavity thereof begins upon exposure to said pressure, said reversal initiation feature being an ablated area located on said bulged section that has been subjected to an ablation operation in which the thickness of said bulged section has been reduced by the ablation of disc material therefrom and having a thickness that is less than the thickness of the bulged section surrounding said ablated area, said ablated area including a first ablated portion and a second ablated portion, said first and second portions being located within the same face of said central bulged section, said second ablated portion having a depth that is greater than the depth of said first ablated portion, at least part of said second ablated portion being located within the margins of said first ablated portion.