Apparatus are provided for an access system for a passage defined in a component. The passage is surrounded by a flange, and the access system comprises a plug adapted to be coupled to the flange of the component to seal the passage. The plug includes a sidewall and an overhang coupled to the sidewall. The overhang is configured to substantially surround at least a portion of the flange and the plug is movable between a first, unsealed position and a second, sealed position upon the application of a force.

Apparatus are provided for an access system for a passage defined in a component. The passage is surrounded by a flange, and the access system comprises a plug adapted to be coupled to the flange of the component to seal the passage. The plug includes a sidewall and an overhang coupled to the sidewall. The overhang is configured to substantially surround at least a portion of the flange and the plug is movable between a first, unsealed position and a second, sealed position upon the application of a force.

A lid for a utilities vault having a moldable core and a reinforcement matrix positioned within the core, the reinforcement matrix including longitudinally and laterally extending intersecting members and a plurality of lid feature housings positioned on and attached to the intersecting members, the lid feature housings extending through the core and protruding to the upper and lower surfaces of the lid, and the plurality of longitudinally and laterally extending intersecting members have a height sufficient to provide reinforcement without a perimeter member for the reinforcement matrix.

A manway cover assembly can be used to control access to the interior of a railroad tank car or other type of tank or structure. The manway cover assembly can have a tightening system, such as a screw tightening system and an attachment system. The attachment system can have a ledge configured to engage a flange that surrounds an opening. A cover can control access to the opening. The tightening system can secure the ledge to the flange and lock the cover over the opening. A manway cover assembly can also be used for selectively sealing an access passageway of a tank. The manway cover assembly can have an internal seal that remains sealed independent of movement between the cover and the opening within a set range of movement.

A manway cover assembly can be used to control access to the interior of a railroad tank car or other type of tank or structure. The manway cover assembly can have a tightening system, such as a screw tightening system and an attachment system. The attachment system can have a ledge configured to engage a flange that surrounds an opening. A cover can control access to the opening. The tightening system can secure the ledge to the flange and lock the cover over the opening. A manway cover assembly can also be used for selectively sealing an access passageway of a tank. The manway cover assembly can have an internal seal that remains sealed independent of movement between the cover and the opening within a set range of movement.

A plastic article useful as a riser assembly for a septic tank or as part of another structure is comprised of a multiplicity of identical shape conical wall plastic risers. The risers are attached to each other at joints by tabs which engage rim segments; each end of the riser has alternating tabs and rim segments. A riser assembly wall undulates in the lengthwise direction. The risers nest within each other for shipment or storage.

A multipurpose relocatable structure includes a floor system, a framework secured to the floor system, and walls coupled to the framework. The walls include a number of panels that are secured along adjacent vertical edges. The multipurpose relocatable structure may include a preconfigured interior, one or more doors having an emergency escape hatch, a protected electrical connector, an environmental control system that is configurable between operational and transport configurations, and lifting corners having securement apertures.

A multipurpose relocatable structure includes a floor system, a framework secured to the floor system, and walls coupled to the framework. The walls include a number of panels that are secured along adjacent vertical edges. The multipurpose relocatable structure may include a preconfigured interior, one or more doors having an emergency escape hatch, a protected electrical connector, an environmental control system that is configurable between operational and transport configurations, and lifting corners having securement apertures.

A tank assembly for receiving liquids comprises a tank body. The tank body includes a tank wall defining an enclosed tank cavity. The tank body also includes a manhole lid attached to the tank wall and movable from a closed position covering a manhole in the tank body to an open position uncovering the manhole. A liner includes a flexible liner wall defining an enclosed liner cavity. An opening is formed in the liner wall to permit liquid to be introduced into the liner cavity. The liner also includes a fitting secured to the liner wall at the opening in the liner wall. A first end of a hose is attached to the fitting for conducting fluid to the liner cavity. A valve is attached to a second end of the hose. The valve and the second end of the hose are releasably attached to the manhole lid.

A tank assembly for receiving liquids comprises a tank body. The tank body includes a tank wall defining an enclosed tank cavity. The tank body also includes a manhole lid attached to the tank wall and movable from a closed position covering a manhole in the tank body to an open position uncovering the manhole. A liner includes a flexible liner wall defining an enclosed liner cavity. An opening is formed in the liner wall to permit liquid to be introduced into the liner cavity. The liner also includes a fitting secured to the liner wall at the opening in the liner wall. A first end of a hose is attached to the fitting for conducting fluid to the liner cavity. A valve is attached to a second end of the hose. The valve and the second end of the hose are releasably attached to the manhole lid.