Abstract: A fluid flow monitor has coaxial conductive annular supports separated by an insulating gasket and connected by a conductive member. One support has a lesser external diameter and a smaller internal diameter than the other to reduce the chance of accidental short circuiting. Wires are attached to each support, a third wire supplies a floating ground to ensure monitor tripping is not caused by a ground fault. Tabs on the inner perimeter of the supports may mount the conductive member.

Abstract: A fluid flow monitor has coaxial conductive annular supports separated by an insulating gasket and connected by a conductive member. One support has a lesser external diameter and a smaller internal diameter than the other to reduce the chance of accidental short circuiting. Wires are attached to each support, a third wire supplies a floating ground to ensure monitor tripping is not caused by a ground fault. Tabs on the inner perimeter of the supports may mount the conductive member.

Abstract: An improvement is provided in a safety pressure relief device adapted to be installed between a standard base flange and a standard hold-down flange including a first crowned rupture member, a second crowned rupture member, a resilient sealing membrane, the resilient sealing membrane being positioned between the first crowned member and the second crowned member, the first crowned member being positioned with respect to the second crowned member with its convex side away from the second crowned member, the convex side of the second crowned member being away from the first crowned member, both the first and second crowned members being perforate to allow pressure fluids to pass therethrough to be exerted against the sealing member, and means securing the first crowned rupture member and the second crowned rupture member to the resilient sealing member.

Abstract: A reverse buckling rupture disc safety device wherein there are associated cutting means, these cutting means releasably mounted in a sub-assembly, allowing ready replacement of the cutting means.