Abstract: A device for emergently relieving pressure comprises a flexible plate bent downward and having its periphery attached to the inner surface of a hatch coaming, wherein the periphery of the plate is welded to the inner surface of the coaming at appropriate intervals, and the gap between the remaining part of the periphery of the plate and the coaming inner surface is sealed by a sealant.When a specified pressure exerts on the flexible plate, the plate starts bending back upward. With the upward bending of the plate, the welds between the plate and the coaming are deformed and broken, allowing the plate to be blown off from the coaming. Thus the device, if installed on a fuel tank, serves to relieve the pressure in the tank for the maintenance of safety.

Abstract: A heat insulating construction, formed on the hold bottom plates below a spherical tank of a liquified gas carrying vessel, consists of blocks of rigid urethane foam bonded to the hold bottom plates, filling members such as fiber glass inserted into the joints between the rigid foam blocks and adhesively bonded thereto, and a layer of glass mesh and adhesive covering the rigid foam blocks and filling members.

Abstract: A secondary insulating barrier for protecting the hold of a ship below a spherical low temperature liquified gas storage tank installed therein comprises at least two layers of rigid foam synthetic resin sprayed on the hold plates and covered by a layer of glass mesh and adhesive. Alternatively, the layers of synthetic resin, glass mesh and adhesive are applied to plywood attached to the hold plates by joists, thus forming an air space between the secondary barrier and the hold plates. Where the hold plates have a multi-surface construction, laminated rigid urethane foam blocks are butted end-to-end and are bonded to each other and to the plywood sheets at the corners between adjacent hold plates, the spray-formed layers are applied between the blocks, and the whole is covered by a protective layer of glass mesh and adhesive.

Abstract: A heat insulating construction for the outer wall of a low temperature liquified gas storage tank comprising a number of blocks or plates of rigid foam insulating material bonded to the outer wall, with seats for receiving pressing jigs for the bonding operation secured to the outer wall in the joints between the insulating blocks. The joints are filled with soft synthetic foam, embedding the seats therein, a moisture-proof layer covers the insulating blocks and joints, and a water-proof material covers the moisture-proof layer.

Abstract: An insulating construction for a low temperature liquified gas storage tank consists of a plurality of heat insulating blocks or plates of rigid foam, each covered with a gas-tight sheet bonded thereto and each bolted at its approximate center to the outer wall of the tank. The joints between adjacent plates are filled with a heat insulating material and a gas-tight cover is applied to the exposed portions of this filler material and to the exposed ends of the bolts. Preferably, the inner surfaces of the plates are separated from the outer wall of the tank by spacers, providing a space which is filled with a soft foam resin and which forms a passage for conducting any leakage gas from the tank to a pipe located in a plate below the bottom of the tank and discharging such gas to the outside of the insulating construction.