A cryogenic tank for an aircraft providing a tank access for maintenance and repairing services of equipment inside the tank onboard of the aircraft. An access opening is closed by a removable closure including a multiple wall panel which is vacuum insulated and which is configured and fitted to the multiple tank wall in a manner that the heat ingress into the cryogenic tank is minimized and that no vacuum is impacted by opening and closing the removable closure.

Described herein is an improved externally mounted pressure relief valve that is especially adapted for rail tank cars or other large closed containers that contain or transport fluids, including liquids and gases. The pressure relief valve comprises a plurality of spring assemblies, and each spring assembly contains a pre-determined number of spring leaves. Each spring assembly is coiled upon a corresponding spring drum, and each spring drum is penetrated by a corresponding spring drum bolt. The spring assemblies are preferably aligned in at least two horizontal planes that are parallel to each other and normal to the vertical length of a spring block. The spring block and sealing disk are mounted vertically over the valve seat and within the confines of vertically extending spring brackets.

Described herein is an improved externally mounted pressure relief valve that is especially adapted for rail tank cars or other large closed containers that contain or transport fluids, including liquids and gases. The pressure relief valve comprises a plurality of spring assemblies, and each spring assembly contains a pre-determined number of spring leaves. Each spring assembly is coiled upon a corresponding spring drum, and each spring drum is penetrated by a corresponding spring drum bolt. The spring assemblies are preferably aligned in at least two horizontal planes that are parallel to each other and normal to the vertical length of a spring block. The spring block and sealing disk are mounted vertically over the valve seat and within the confines of vertically extending spring brackets.

In general, in one aspect, embodiments disclosed herein relate to a system for supporting a tool in a manway. The system includes a tool holding device. The tool holding device includes a holder plate, a hinge attached to the holder plate, a holder arm attached to the hinge, a clamp attached to the holder arm, and a resting arm attached to the clamp. The holder plate includes a first connector. The hinge permits swinging the tool holding device into and out of a manway. A second connector is included on the manway to be compatible with the first connector.

Described herein is an improved externally mounted pressure relief valve that is especially adapted for rail tank cars or other large closed containers that contain or transport fluids, including liquids and gases. The pressure relief valve comprises a plurality of spring assemblies, and each spring assembly contains a pre-determined number of spring leaves. Each spring assembly is coiled upon a corresponding spring drum, and each spring drum is penetrated by a corresponding spring drum bolt. The spring assemblies are preferably aligned in at least two horizontal planes that are parallel to each other and normal to the vertical length of a spring block. The spring block and sealing disk are mounted vertically over the valve seat and within the confines of vertically extending spring brackets.

There is provided herein a pipeline closure which is machined as a single piece. In this embodiment, the pipeline closure comprises a door frame which is integral to a flange containing some number of holes for lug bolts along its periphery, the purpose of the holes being to provide a means of attaching the closure to the end of a pipe as is conventionally done. A door is positionable to be opened to allow access to the interior of the pipe or pressure vessel to which the quick opening closure is attached. Unlike prior art closures, the quick opening closure does not have a weld joint that is a potential weak point in the mechanism. Additionally, this embodiment does not require as much space to mount or attach as prior art closures.

A frangible closure coupling is used with or on pipe of a tank that contains a potentially dangerous fluid, such as liquid natural gas. The closure coupling mitigates the uncontrolled release of fluid from the tank in the event of a rupture of a pipe attached to the tank.

A hollow roto-moulded article, having an inner wall defining an interior of the article and integrally formed structure with the inner wall, the integrally formed structure protruding away from the interior of the article, the article formed of a first layer including one or more thermoplastic polymers, and a second layer including one or more fibrous materials.