A safety grill or grate for use with a camera and the like during maintenance.

A flange cover mounting and dismounting device, which comprises: a base part, comprising a fastener element with a fastener hole array, and being fastened on a flange cover mounting surface by the fastener hole array; and a jib arm assembly, having a first end being pivotally connected to the fastener element, and a second end being connected to the flange cover. The flange cover mounting and dismounting device can be fixed to the flange cover mounting surface having a corresponding fastener hole array, which is convenient for mounting and dismounting a flange cover. In addition, under most circumstances, the fastener hole array on the flange cover mounting surface is intrinsically owned by the devices, which originally can be applied to connect modules of each device or used for other applications.

A temporary manhole cover includes a hinge to permit a portion of the cover to be pivoted open and closed. And a roller for use with a hose or rope facilitates cleaning and inspection of the manhole.

A manhole device and corresponding system including a manhole is described. The manhole device comprises a main body having an upper portion, a lower portion and a securing means. The securing means is engageable with the manhole such that when secured to the manhole, the upper portion protrudes above a surface level and the lower portion is retained below the surface level in the manhole. The main body provides means for alignment for construction around the manhole while providing a barrier to prevent access to vehicles, people and debris during the construction process. A method of construction is also provided.

A liner for a manhole cover is made up of stackable sections. Each stackable section is formed of a plurality (e.g. 4) pieces. Each piece comprises a first arm and a second arm which are substantially perpendicular to one another, the first arm being longer than the second arm, and both arms comprising connection means to allow the pieces to be connected together. The respective dimensions of the first arm and the second arm are chosen such that, when the piece is incorporated into a stackable section comprising three other corresponding pieces that are connected to each other in a sequence of a second arm of one piece connected to the first arm of an adjacent piece to form a quadrilateral stackable section, a further corresponding piece can fit within the stackable section along an axis substantially parallel to the longitudinal axis of the first arm. Further corresponding pieces can thus be arranged within a complete stackable section to maximize the number of pieces that can be transported in a given space.

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.

Described are hatch assemblies comprising a frame having sidewalls, a pivotally connected cover, and a number of easily repairable and replaceable torsion-spring-assisted hinge assemblies. Hinge assemblies may comprise a torsion spring having a coiled body along the center axis of which a carriage bolt is inserted. Once one end of the torsion spring that extends vertically from the center axis is engaged by a support member, such as a semi-open enclosure that is mounted on a hinge plate, the spring is rotated and supports the torque generated by the weight of the cover when operated by a user. Advantageously, this provides for a controlled and almost effortless opening and closing of a heavy door or covers of hatch assemblies.

In the present invention, when a circular lid body is opened or closed by a hinge-coupling structure at an eccentric location out of a circle, the circular lid body can be opened or closed without interference between an edge protrusion part of the circular lid body and a circular edge support frame of a support frame body. Therefore, the present invention is useful in that the present invention has overcome innumerable interferences on arcs through a curve insertion scheme of a circular structure, that is, a curve insertion scheme by a rotational inclination angle ? of the edge protrusion part and an operation model view of an S-shaped hinge curve part.

A system and method for protecting workers, vehicles, and well-heads by enclosing well-site cellars with a series of framed plates. Each plate is perforated and configured for lifting with holes for hoisting the plates. Each plate is lipped to be retained by longitudinal edges of the cellar. A plurality of plates supports a platform for supporting a pipe wrangler adjacent a cellar based wellbore.

A hatch assembly comprising a frame presenting a frame opening, a hatch for opening and closing the frame opening, a plurality of pivot assemblies. At least two pairs of the pivot assemblies each provide a hatch pivot axis at or adjacent a side of the hatch, an engagement mechanism engagement mechanism configured to releasably engage the pivot assemblies to couple the hatch to the frame, and an actuation mechanism. The engagement mechanism comprises a plurality of pins, each pin movable between an extended position to engage a said pivot assembly and a retracted position to disengage from the pivot assembly. The pins are oriented so that longitudinal axes of the pins in each pair of pins converge enabling the hatch to remain coupled to the frame when the hatch is pivoted between the closed position and an open position.