Abstract: Typically, for automatically dosing shutoff valves, a valve closing body is held in the open position by fixation with soft solder and can be moved into the closed position by means of a spring action. The disadvantage is that it can only be used on small valves and is restricted to the direct influence of temperature on the shut-off valve itself. Hence, the invention provides improvement using a reaction line and a hollow body to form a closed system. The reaction line which is thermo-sensitive all over its length can be laid at any desired distance from the shut-off device so that a fire occurring at a distance from the shut-off device triggers the closing action. The reaction line can, for example, be arranged in a metering and regulating station so that it stretches over the entire station. The advantage of the design as a reaction line is that the reaction time with regard to fire fighting is reduced to a minimum.

Abstract: The ball valve comprises a body (1) provided with two coaxial pipe stubs (4, 5) wherein a ball means (2) rotatable by means of a rotating shaft device floats. In the closed position, the downstream face of the spherical circumference (12) of said ball means mates with a complementary sphere-bent annular body sealing surface (11), a pressure difference building up between the upstream and the downstream sides of said ball means. Said ball means and said sealing surface form a primary sealing system (11, 12) concentric with the pipe stub axis (10). The sealing function of said primary sealing system is reliably achieved by means of a block and bleed system, the annular body sealing surface (11) being split by an annular groove (13) in the wall of said body concentric with said pipe stub axis (10) connected with the control line (14) of a bleed system (14, 15) penetrating said body wall.