Pressure hardware for a modular inter-wall elastomer seal

Claim 1

In a seal block assembly for forming a modular, annular conduit-to-wall-opening seal of the kind comprising a plurality of elastomer seal blocks joined to each other in an annulus around a conduit, each seal block having at least one pressure bolt aperture therethrough parallel to the conduit axis, the seal blocks being axially compressed and radially expanded to form a seal between the conduit and an external encompassing wall, the assembly including a plurality of sets of pressure hardware for compressing and expanding the seal blocks, each set of pressure hardware comprising: a bolt having a plural-facet head of given size and shape integral with one end of a bolt rod, the bolt rod having a threaded portion extending longitudinally from its other end toward its bolt head end; a first molded resin pressure plate having a recess larger than the bolt head so that the bolt head seats in freely rotatable relation in the recess, with peripheral access for a wrench around the bolt head and with no metal-to-metal sliding contact when the bolt is tightened; the recess being deep enough so that the bolt head does not project substantially out of the recess; a second molded resin pressure plate having a stepped socket facing outwardly of the pressure plate, the socket having an inner plural-facet socket portion of predetermined depth and given maximum transverse dimension and an outer socket portion having a transverse dimension greater than the maximum transverse dimension of the inner socket portion, with a shelf at the outer edge of the inner socket portion affording an annular bottom surface for the outer socket portion; and a plural-facet nut of predetermined size and shape, complementary to the inner socket portion so that the nut seats entirely therein in non-rotatable relation, the nut having an internal aperture threaded to engage the threaded portion of the bolt rod, the nut having an integral flange on its outer side, engaging the bottom surface of the outer socket portion to distribute stress from the bolt and nut to the second pressure plate; the second pressure plate further having a second bolt-receiving aperture therethrough, smaller than the nut, aligned with the socket to admit the other end of the bolt rod into engagement with the nut.