Disclosed is a cover for a utility vault and a method for making such covers. The cover is formed from fiberglass reinforcement layers and a polymer mix matrix. The reinforcement layers include a bottom reinforcement layer, one or more edge reinforcement layers, and a top reinforcement layer. A first portion of the edge reinforcement layer overlaps a portion of the bottom reinforcement layer and a second portion of the edge reinforcement layer overlaps a portion of the top reinforcement layer. The reinforcement layers are formed from fiberglass fabric and may include fiberglass layers whose fibers are oriented quadraxially. The polymer mix impregnates the fabric layers and forms the bulk of the cover. The polymer matrix bonds the reinforcement layers so that forces applied across the top and bottom layers are communicated to the edge reinforcement layer. The polymer matrix includes a thermoset polymer resin and an expanded glass bead filler.

A subgrade vault system with a locking lid assembly is provided. Specifically, a subgrade vault suitable for housing utility and similar equipment is provided, the vault comprising a main body portion, a cap, and a lid that may be selectively secured with one or more rotatable locking mechanisms to prevent or deter unauthorized access to vault contents.

A manway open and close assist device that is operably connected to at least one upper hinge attachable to a manway cover and a lower hinge attached to a vessel or tank. The device comprises. A disc-like piston is mounted on a threaded input screw and at least one anti-rotation member to provide linear translation of the piston due to rotation of the input screw. A cylindrical and tubular housing that receives the threaded input screw, the anti-rotation member, and the piston, wherein the housing has a plurality of helical grooves disposed in its inner surface that receive teeth on the outer surface of the piston. The housing may be fixed to the upper hinge member(s) and a rotation of the housing and attached hinge member(s) is effectuated by rotating the input screw and resulting linear movement of the piston to open and close the manway cover.

A manway open and close assist device that is operably connected to at least one upper hinge attachable to a manway cover and a lower hinge attached to a vessel or tank. The device comprises. A disc-like piston is mounted on a threaded input screw and at least one anti-rotation member to provide linear translation of the piston due to rotation of the input screw. A cylindrical and tubular housing that receives the threaded input screw, the anti-rotation member, and the piston, wherein the housing has a plurality of helical grooves disposed in its inner surface that receive teeth on the outer surface of the piston. The housing may be fixed to the upper hinge member(s) and a rotation of the housing and attached hinge member(s) is effectuated by rotating the input screw and resulting linear movement of the piston to open and close the manway cover.

This disclosure is directed toward a heated tailgate for use in cold climates. The heated tailgate may be used with a self-contained heated portable vacuum slurry box. The slurry box generally includes a vacuum tank, a structure attached to the tank, a vertical tailgate, and a hook for pulling the slurry box onto a vehicle. The heated tailgate provides that the slurry cuttings within the slurry box which are adjacent to the tailgate do not freeze and provides for a way in which the tailgate may seal to the vacuum box.

This invention is a mechanism enabling rapid manual opening and closing of a pressure vessel lid without using tools. A pressure vessel bears two circular mating rings welded to the adjacent rims of the vessel lid and shell respectively with the latter ring grooved to house an O-ring. These mating rings are externally tapered to match the internal tapers of a pair of semi-circular external clamping elements. The mechanism applies tension at the vessel perimeter to draw the external clamping elements radially inward, engaging male and female tapers with sufficient force to compress the O-ring and maintain static clamping of the pressurized lid and shell. Tension is produced by levered rotation of two diametrically-opposed slotted plates where cylindrical pins mounted on the ends of the external clamping elements ride in the plate slots and cam action applies mechanical advantage causing the pins to converge. The mechanism incorporates very few components which are readily manufactured and multiple safety features prevent unintentional actuation.

A tank cover, especially a cover on a sewage treatment tank, is provided with an access opening with a liftable hatch cover. Along with the hatch cover is a safety barrier or grate, either connected directly to the hatch cover or to structure surrounding the hatch opening. When the hatch is opened the barrier is deployed to prevent a worker from accidentally falling through the opening. In one form the barrier is pivotally attached to the bottom side of the hatch cover, and can be swung out as the hatch is opened to form an A shaped or roof shaped barrier, with the hatch cover and the barrier both inclined and essentially forming a roof over the opening. Braces or struts hold these components in the erected position and provide barriers from the sides. For entry of a person through the opening, the barrier or grate can be retained against the bottom of the hatch cover as the cover is swung fully open, through 180. In another form the barrier is secured to tank cover structure just below the hatch cover and can be left in place as a horizontal barrier when the cover is fully opened. For access into the tank the barrier/grate can be swung back in the same direction as the access cover and stacked on the opened access cover.

An apparatus includes a superstructure including cylindrical vessel with a conical bottom section and an opening near the base of the cone; an air assisted puffer device near the base of the cone; an air blower attached near the base of the cone, wherein the air blower is configured to produce air velocities of at least about 40 ft/min; a gently sweeping elbow attached after the blower exit; and a hatch fitted to the top of the vessel that allows for a funnel to be connected to the tank thereby allowing bulk barite powder to be loaded into the top of the tank from bulk bags. A barite powder blend including: a blend of barite particles with a size of about 1 micron and barite particles with a size of at least about 325 mesh, wherein the D50 of the blend is not greater than about 325 mesh.

An apparatus includes a superstructure including cylindrical vessel with a conical bottom section and an opening near the base of the cone; an air assisted puffer device near the base of the cone; an air blower attached near the base of the cone, wherein the air blower is configured to produce air velocities of at least about 40 ft/min; a gently sweeping elbow attached after the blower exit; and a hatch fitted to the top of the vessel that allows for a funnel to be connected to the tank thereby allowing bulk barite powder to be loaded into the top of the tank from bulk bags. A barite powder blend including: a blend of barite particles with a size of about 1 micron and barite particles with a size of at least about 325 mesh, wherein the D50 of the blend is not greater than about 325 mesh.

Embodiments described in this specification are generally directed to a bolted hinge assembly for a waterbox cover (a waterbox hinge assembly). The waterbox hinge assembly generally does not require welding on the waterbox cover or the heat exchanger in an HVAC system (HVAC unit hereinafter). Further, the waterbox hinge assembly may be installable to the HVAC unit without removing the heat exchange fluids (e.g., water, refrigerant, etc.) from the HVAC unit. In some embodiments, the waterbox hinge assembly can be installed on an HVAC unit without removing any bolts from the waterbox cover. Once installed, the waterbox hinge assembly can be left in place so that it can be reused anytime the HVAC unit is serviced.