A fluid shut-off device for high temperature employments, for example in the petrochemical field, comprising: - a valve body which extends axially along a body axis between two opposite openings (3, 4) for the inlet and outlet of the fluid, the valve body being provided, at each end thereof delimiting a respective opening, with connection means to a respective joining member to be joined to a fluid inlet or outlet duct; - a shutter rotatably placed in the valve body between the two inlet/outlet openings (3, 4), the shutter being crossed by an axial passageway suitable to put the two opposite openings (3, 4) into fluid communication and being rotatable between a closed position, in which it prevents the passage of the fluid from one opening to the other opening of the valve body, and an open position, in which it allows the passage of the fluid between the two openings of the valve body; - two shutter seats which rotatably support the shutter, wherein each shutter seat is supported by or is integral with a respective drawer; wherein each drawer is elastically affected by a respective elastic compensation member which applies to the drawer a compensation pressure directed towards the shutter, and wherein a head is inserted, with shape and/or force coupling, into each of the inlet/outlet openings (3, 4) of the valve body, the head defining an axial abutment for a respective elastic compensation member, wherein each head has an outer side wall which sealingly engages an inner side wall of the valve body, is axially crossed by a head opening for the passage of the fluid, and is inserted into the respective opening without engaging said connection means with the joining member, characterized in that the outer wall of the head and the inner side wall of the valve body are connected to each other by means of bayonet coupling. - a valve body which extends axially along a body axis between two opposite openings (3, 4) for the inlet and outlet of the fluid, the valve body being provided, at each end thereof delimiting a respective opening, with connection means to a respective joining member to be joined to a fluid inlet or outlet duct; - a shutter rotatably placed in the valve body between the two inlet/outlet openings (3, 4), the shutter being crossed by an axial passageway suitable to put the two opposite openings (3, 4) into fluid communication and being rotatable between a closed position, in which it prevents the passage of the fluid from one opening to the other opening of the valve body, and an open position, in which it allows the passage of the fluid between the two openings of the valve body; - two shutter seats which rotatably support the shutter, wherein each shutter seat is supported by or is integral with a respective drawer; wherein each drawer is elastically affected by a respective elastic compensation member which applies to the drawer a compensation pressure directed towards the shutter, and wherein a head is inserted, with shape and/or force coupling, into each of the inlet/outlet openings (3, 4) of the valve body, the head defining an axial abutment for a respective elastic compensation member, wherein each head has an outer side wall which sealingly engages an inner side wall of the valve body, is axially crossed by a head opening for the passage of the fluid, and is inserted into the respective opening without engaging said connection means with the joining member, characterized in that the outer wall of the head and the inner side wall of the valve body are connected to each other by means of bayonet coupling.