Patent ID: 7950409

Claim:
An activation rupture disc unit capable of withstanding a substantially higher back pressure than its burst activation pressure, said unit comprising: a tubular housing having a fluid activation passage, said housing being provided with wall structure defining at least a portion of the fluid activation passage, said portion of the passage having a fluid inlet and a fluid outlet, said wall structure being tapered in a direction such that the fluid inlet of said portion of the activation passage is of less area than the area of the fluid outlet; a rupture disc mounted within the housing in disposition with a central section thereof in fluid-blocking relationship to said outlet of the tapered portion of the activation fluid passage; and a tapered, self-releasing plug positioned in said tapered portion of the fluid activation passage in supporting relationship to the central section of the rupture disc, said plug having surfaces conforming to and engaging the taper of said wall structure and the central section of the disc, respectively, while the rupture disc central section is in fluid blocking relationship to the fluid activation passage, said plug being of sufficient mass to support and prevent rupture of the disc under a back pressure acting upon the disc that is substantially greater than the activation pressure of the disc, said rupture disc having a central bulged section extending across the outlet of the tapered portion of the activation passage, said bulged section having opposed concave and convex surfaces, said plug being provided with a hemispherical end face generally conforming to and engaging the proximal concave surface of the rupture disc.