Patent ID: 8863844

Claim:
A subsea arrangement arranged to form a heat bank for thermally insulating one or more elements of a subsea installation, the subsea arrangement comprising: an external casing enclosing an internal space arranged to accommodate seawater therein having a heat-storing capacity, and arranged to receive said one or more elements of the subsea installation when operationally employed subsea so as to allow heat stored in the seawater within the internal space surrounding the one or more elements to slow cooling of the one or elements, and a pressure equalizing valve for equalization of fluid pressure in said internal space, comprising: a swing arm; a valve member arranged inside the casing, the valve member being carried by the swing arm; and a first end on the swing arm being articulately connected to the casing through a joint so as to be pivotable in relation to the casing about a horizontal or at least essentially horizontal pivot axis, the valve member being secured to the swing arm at a distance from the first end of the swing arm; wherein the swing arm is pivotable about the said pivot axis in a first direction, under the effect of an external fluid pressure acting on the valve member, from a resting position in which the valve member covers an opening provided in the casing to prevent the seawater from flowing through this opening, to a raised position in which the valve member uncovers said opening to allow the seawater to flow through the opening from the surroundings into said internal space for equalization of the fluid pressure therein when the subsea arrangement is lowered into the sea, and wherein the swing arm is pivotable in a second direction, under the effect of gravity, from the raised position to the resting position to thereby prevent seawater from flowing into and out of said internal space when the fluid pressure in said internal space is balanced against the external fluid pressure acting on the valve body, the second direction being opposite the first direction.