Abstract: A safety pressure relief assembly of the rupture disc type guards against pressure differentials, beyond a predetermined range in a vent system, and includes a relief disc perforated to permit reverse flow without rupture, a sealing disc positioned adjacent the relief disc and blocking positive flow through the perforations, a support member with a stay structure positioned to support the sealing disc nested within the relief disc, and a cutting member positioned to cut the sealing disc at a predetermined vacuum within the vent system. The relief disc has a concave surface and a convex surface. When a predetermined vacuum pressure differential is applied to the assembly, the sealing disc and the support structure are inverted to project away from the relief disc.

Abstract: A low pressure venting panel acts to safely vent a pressure vessel, such as a bag house, from overpressure conditions. The venting panel is particularly responsive and predictable at low pressures. The panel includes a thin rupture body with a central group of apertures and slit lines emanating from the apertures. A thin sealing membrane is bonded to one surface of the rupture body at least in the area of the slits. The characteristics of the sealing membrane enable the membrane to resist expansion in the area of the slits when pressure is applied to the rupture body, thereby resisting rupture of the membrane up to the design rupture limit of the venting panel.

Abstract: A safe pressure relief assembly of the reverse acting rupture disc type guards against very low pressure differentials and includes a thin, bulged sealing disc, a cutting member positioned in spaced relation to the sealing disc and extending a substantial transverse distance thereacross and a sealing disc support member having a stay arrangement projecting into supporting engagement with the concave side of the sealing disc, the stay arrangement having a resistance to collapse sufficient to retain the sealing disc out of contact with the cutting member only up to a predetermined differential pressure.

Abstract: A safe pressure relief assembly of the rupture disc type guards against pressure differentials beyond a predetermined range extending both above and below zero and includes a positive relief disc which is perforated to permit negative flow without rupturing, a sealing disc normally blocking the perforations, a cutting member positioned in spaced relation to the sealing disc and extending a substantial transverse distance thereacross and a sealing disc support member having a stay arrangement projecting into negative supporting engagement with the sealing disc, the stay arrangement having a resistance to collapse sufficient to retain the sealing disc out of contact with the cutting member only up to a predetermined negative pressure. The subcombination of sealing disc, stay arrangement and cutting member is separately useful, especially as a very low pressure relief device.

Abstract: A safety pressure relief device of the reverse buckling type includes a puncturing element and a rupture disc having a groove or score line formed in the flange portion of the disc. The score line does not materially affect the rated pressure of the device during normal operation, and functions as a backup safety feature by providing a line of weakness along which the disc will tear if the pressure relief device is accidentally placed in a backward or reversed orientation with respect to the process, and/or if the cutting blades are inadvertently omitted from the rupture disc assembly.

Abstract: A reverse buckling disc arrangement for direct mounting eliminates separate inlet and outlet seating rings for the disc flange. Centering ring units on both sides of the disc have flanges doubling as the seating rings. The centering ring projecting toward the higher pressure supports a screen for protecting the disc dome while permitting necessary flow-through.