Abstract: A gated mold for casting concrete pipe requires no wedges or bolts for securement. A core mold may be contracted by lifting at an actuation point, and expanded by resting on a base ring. An external mold may be expanded by lifting at an actuation point, and contracted by resting on a base ring. The mold gates are opened and closed with sets of collapsing links pivotably attached to a longitudinally extending actuation column. Longitudinal motion of the actuation column forces the links to collapse or extend, thereby expanding or contracting the mold. Appropriately positioned actuation and lifting points are provided such that the mold can be lifted vertically along the longitudinal axis containing the mold center of gravity.

Abstract: A heat ablative coating composition is prepared by combining an epoxy silane resin, an epoxy resin, a silicone intermediate, a silicon-modified polyether, an aminosilane, at least one organometallic catalyst, at least one organic solvent, water, at least one filler, optional nonsilicon-containing amine catalyst, and optional pigments and thixotropic agents. The heat ablative coating composition is applied to a substrate to form a film having a build thickness in the range of from about 0.1 to 0.5 inches that is capable of curing at ambient outdoor temperature in about seven days, depending on ambient conditions. The heat ablative film so formed is designed to undergo a slow thermal decomposition when exposed to high temperature conditions without igniting or causing excessive smoke, and is designed to have good thermal conductivity to protect the underlying substrate from thermal decomposition.

Abstract: A coupling device is used for joining two pipes. Each end of the coupling has a pair of adjoining grooves in its inner surface. Each groove has at its largest diameter a substantially flat portion located at its innermost end and then tapers in the direction of the coupling end. At the junction between the two grooves, the diameter of outermost groove is greater than the diameter of the innermost groove, forming a small circumferential ridge. An O-ring is initially set in the innermost groove and is compressed as the pipe is pushed into the coupling. The O-ring is further compressed as it rolls down the ramp of the inner groove as the pipe is partially retracted from the coupling. As the O-ring is pulled past the circumferential ridge between the grooves, it expands into the flat portion of the outer groove, forming a seal between the pipe and the coupling and a positive indication of sealing.

Abstract: A sprayable, trowelable epoxy polysiloxane based coating and flooring composition exhibiting excellent weatherability in sunlight and superior chemical, corrosion and impact resistance after curing is made up of: (a) a resin component which includes a non-aromatic epoxy resin having at least two 1,2-epoxy groups per molecule; a polysiloxane and an organooxysilane; (b) an difunctional aminosilane hardener component; (c) an organotin catalyst; and (d) an aggregate or pigment component. Organic solvents and flow modifying agents may be added to facilitate spray application. The resin component, hardener component, aggregate component and desired catalysts are combined in the presence of a sufficient amount of water to promote the hydrolysis of polysiloxane and/or organooxysilane and the polycondensation of the silanols produced by such hydrolysis. The aminosilane and epoxide resin react to form a cured linear epoxy polymer.

Abstract: A technique for joining a larger and a smaller pipe wherein the smaller pipe has an outside diameter smaller than the inside diameter of the larger pipe. An inner and an outer gasket are used to form the joint. The inner gasket has an inclined outer surface forming a wedge shaped profile and is stretch fitted over the smaller pipe. The outer gasket has a portion of its inner surface matched to the inner gasket outer surface and is compression fitted into the inner surface of the larger pipe whereby the portion of the smaller pipe having the inner gasket is encased by the larger pipe. The smaller pipe is then pulled away from the larger pipe until the inner gasket wedges against the outer gasket forming a locked sealed joint.