An easy manufacturing method of a slip stopper, and apparatus therefor, that has a great slip stopping effect and can be used for a location where a problem occurs if a though hole is opened therein. After a protruding portion is formed on a steel plate, by using a first punching die unit, so as to protrude from the upper surface in a plate thickness direction, a concave portion and drain channels are formed in the protruding portion by shear planes that extend substantially perpendicular to the steel plate upper surface and have been half-blanked so as not to open a through hole in the steel plate by using a second punching die unit.

The present invention provides an improved rupture disk apparatus and manufacturing method. The apparatus includes a rupture disk having at least one area of weakness formed by the displacement of material through a partial shearing motion. The weakened area is capable of withstanding pressure cycling because the rupture disk flange acts to support the weakened area during use. The apparatus further includes a safety member adjacent to the rupture disk on the outlet side to ensure opening, the safety member having at least one rupture-initiating, stress-concentrating point positioned to contact the rupture disk weakened area.

A rupture disc system comprises a rupture disc including a dome portion and a flange portion interconnected by a transition region and a mounting mechanism for mounting the rupture disc by the flange portion thereof in a pressure relieving vent. The rupture disc includes a thickness reducing groove at least partially circumferentially surrounding the dome portion and located in the transition region thereof. Preferably, the rupture disc is of the reverse buckling type and the groove does not completely surround the dome portion so as to define a tab or hinge within that part of the transition region which is ungrooved or not as deeply grooved as a remainder of the transition region. In addition, the slope or radius of curvature may be increased in the region of the tab. The rupture disc also includes an indentation on the dome portion. The indentation is preferably greatest on the dome portion at a location spaced from the transition region and directly between the tab and a crown of the dome portion. In addition, the mounting mechanism includes a lower ring member having an arcuate projection which extends into the vent. Preferably, the arcuate projection is located so as to be relatively close to and so as to align with the tab such that the dome portion wraps about the projection when reverse buckling and rupture occurs. Methods are disclosed for producing the disc with the groove and the indentation.

The present invention provides an improved rupture disk apparatus and manufacturing method. The apparatus includes a rupture disk having at least one area of weakness formed by the displacement of material through a partial shearing motion. The weakened area is capable of withstanding pressure cycling because the rupture disk flange acts to support the weakened area during use. The apparatus further includes a safety member adjacent to the rupture disk on the outlet side to ensure opening, the safety member having at least one rupture-initiating, stress-concentrating point positioned to contact the rupture disk weakened area.

The present invention provides an improved rupture disk apparatus and manufacturing method. The apparatus includes a rupture disk having at least one area of weakness formed by the displacement of material through a partial shearing motion. The weakened area is capable of withstanding pressure cycling because the rupture disk flange acts to support the weakened area during use. The apparatus further includes a safety member adjacent to the rupture disk on the outlet side to ensure opening, the safety member having at least one rupture-initiating, stress-concentrating point positioned to contact the rupture disk weakened area.