A pressure vessel for holding fluids includes a tank and a coating disposed on an outer surface of the tank. The tank defines a cavity for holding fluids, and an outer surface of the tank includes a first visual characteristic. The coating includes an indicator layer, an outer layer, and a first intermediate layer. The indicator layer is disposed on the outer surface, the indicator layer including a second visual characteristic that visually contrasts with the first visual characteristic. The outer layer is disposed over the indicator layer, the outer layer including a third visual characteristic that visually contrasts with the second visual characteristic. The first intermediate layer is positioned between the indicator layer and the outer layer, the first intermediate layer being visually transparent or translucent. The disclosure also describes a coating including an indicator layer, an outer layer, and a first intermediate layer.

Tank for storing liquefied gas comprising a sealed housing defining a storage space for the liquefied gas, the housing comprising a lower end and an upper end, the tank comprising a device for measuring the level of liquid in the housing, the device for measuring the level of liquid comprising, arranged in the housing, a float and a guide for moving the float, characterized in that the guide comprises an end connected to an upper portion of the housing and a lower end connected to a lower portion of the housing, the float being mounted moveably in translation on the guide such that the float is free to slide along the guide, the device for measuring the level of liquid further comprising at least one float position sensor.

A tank including a liner; a reinforcing layer formed of fiber reinforced resin that is arranged on the liner; a label arranged on the reinforcing layer; and a surface layer formed of glass fiber reinforced resin that is arranged to cover the label. The reinforcing layer includes an inner layer, and an outer layer having a cover rate smaller than the inner layer and smaller than 100%, the cover rate being a percentage of a volume occupied by the fiber reinforced resin in space of the reinforcing layer, and the outer layer being arranged on the inner layer, and at least a part of the label is embedded in the reinforcing layer.

A pressure vessel for holding fluids includes a tank and a coating disposed on an outer surface of the tank. The tank defines a cavity for holding fluids, and an outer surface of the tank includes a first visual characteristic. The coating includes an indicator layer, an outer layer, and a first intermediate layer. The indicator layer is disposed on the outer surface, the indicator layer including a second visual characteristic that visually contrasts with the first visual characteristic. The outer layer is disposed over the indicator layer, the outer layer including a third visual characteristic that visually contrasts with the second visual characteristic. The first intermediate layer is positioned between the indicator layer and the outer layer, the first intermediate layer being visually transparent or translucent. The disclosure also describes a coating including an indicator layer, an outer layer, and a first intermediate layer.

Provided are a method for producing a tank with an outer surface profile that allows a thin label to be easily and firmly attached to a surface thereof, and also such a tank. The method for producing the tank, which includes winding fiber bundles containing an uncured resin component in multiple layers around the outer surface of a liner in a first pitch width so as to form a fiber reinforced resin layer, further includes: winding fiber bundles in a second pitch width wider than the first pitch width so as to form a gap with a required width where no fiber bundle is present between adjacent fiber bundles in winding the fiber bundles to form an outermost layer; shaving off a tip end portion of a projection made of a resin that has cured after bleeding into the gap, with a portion of the projection in a predetermined height left unshaved; and attaching a label to a surface obtained through shaving off the tip end portion.

Provided are a method for producing a tank with an outer surface profile that allows a thin label to be easily and firmly attached to a surface thereof, and also such a tank. The method for producing the tank, which includes winding fiber bundles containing an uncured resin component in multiple layers around the outer surface of a liner in a first pitch width so as to form a fiber reinforced resin layer, further includes: winding fiber bundles in a second pitch width wider than the first pitch width so as to form a gap with a required width where no fiber bundle is present between adjacent fiber bundles in winding the fiber bundles to form an outermost layer; shaving off a tip end portion of a projection made of a resin that has cured after bleeding into the gap, with a portion of the projection in a predetermined height left unshaved; and attaching a label to a surface obtained through shaving off the tip end portion.

A tank including a liner; a reinforcing layer formed of fiber reinforced resin that is arranged on the liner; a label arranged on the reinforcing layer; and a surface layer formed of glass fiber reinforced resin that is arranged to cover the label. The reinforcing layer includes an inner layer, and an outer layer having a cover rate smaller than the inner layer and smaller than 100%, the cover rate being a percentage of a volume occupied by the fiber reinforced resin in space of the reinforcing layer, and the outer layer being arranged on the inner layer, and at least a part of the label is embedded in the reinforcing layer.

Provided are a method for producing a tank with an outer surface profile that allows a thin label to be easily and firmly attached to a surface thereof, and also such a tank. The method for producing the tank, which includes winding fiber bundles containing an uncured resin component in multiple layers around the outer surface of a liner in a first pitch width so as to form a fiber reinforced resin layer, further includes: winding fiber bundles in a second pitch width wider than the first pitch width so as to form a gap with a required width where no fiber bundle is present between adjacent fiber bundles in winding the fiber bundles to form an outermost layer; shaving off a tip end portion of a projection made of a resin that has cured after bleeding into the gap, with a portion of the projection in a predetermined height left unshaved; and attaching a label to a surface obtained through shaving off the tip end portion.

A tank manufacturing method includes the steps of (a) forming a reinforcing layer before hardening, (b) embedding at least a part of a label into the reinforcing layer before hardening, and (c) winding glass fiber with thermosetting resin before hardening impregnated so as to cover the label to form a surface layer before hardening. The step (a) includes (a1) forming an inner layer before hardening, and (a2) forming an outer layer before hardening having a cover rate lower than the inner layer before hardening and lower than 100%, the outer layer before hardening being arranged on the inner layer before hardening.

A compressed fluid energy storage system includes a submersible fluid containment subsystem charged with a compressed working fluid and submerged and ballasted in a body of water, with the fluid containment subsystem having a substantially flat portion closing a domed portion. The system also includes a compressor and an expander disposed to compress and expand the working fluid. The fluid containment subsystem is at least in part flexible, and includes an upper portion for storing compressed energy fluid and a lower portion for ballast material. The lower portion may be tapered proximate the flat portion to prevent it from being collapsed by ballast materials. The region between the fluid and the ballast has exchange ports to communicate water between the inside and outside of the containment subsystem. In other embodiments, an open-bottomed fluid containment system is held in position underneath a ballast system by a tensegrity structure.