Abstract: The invention relates to a sealing device for such throttle valves as comprise a valve housing with a valve seat and a pivotally mounted throttle member which may be pressed against the valve seat to bring about a sealing contact between two interacting sealing surfaces, one on the throttle member and the other in the valve housing and a sealing ring to be mounted in a slot in the valve. The invention is characterized in that the sealing ring (5) has a cross-section of a homogeneous, radially elongated body part (8) of considerable rigidity and resistance to radial deformation, that said body part at its head end (11) has a sealing surface (12) which is one of the two said sealing surfaces, and that from the "hip" part of the said homogeneous body part extend two essentially radial legs (14, 15), which form flanges of the sealing ring, said flanges being arrnaged to be pressed axially against the walls (18, 19) of said slot.

Abstract: A valve seat contains a seat ring (12) with flat, parallel side faces (19, 20). The seat ring consists of steel or possibly of PTFE. When the valve is being shut by a throttle (1), a sealing surface of the throttle is pressed against the seat ring which adopt itself as to form and position to the mean line of the throttle, and the seat ring is displaced in a groove (18) in the plane of the seat. A couple of spring washers (10, 11) sealingly engage the parallel side faces of the seat ring. When the throttle is reopened the spring washers secure the seat ring in its position.

Abstract: A butterfly valve with a seal face (4)having two opposite, essentially spherical sections (h, i) intersected by a symmetry plane (k) through the throttle which coincides with an axis through a point (n) parallel with the torsional axis (j) of the throttle and two opposite, essentially conical sections (f, g) on both sides of the symmetry plane. The spherical and the conical sections successively merge into each other. When the throttle is revolved to shutting position, the sealing line (a) which has circular shape is pressed against a valve seat (18) shaped as a circular ring made of steel. An eccentrical location of the torsional axis (j) will cause that a surface contact between throttle and valve seat wil occur simultaneously along the entire sealing line in the shutting movement.

Abstract: A butterfly valve with a seal face (4) having two opposite, essentially spherical sections (h, i) intersected by a symmetry plane (k) through the throttle which coincides with the torsional axis (j) of the throttle and two opposite, essentially conical sections (f, g) on both sides of the symmetry plane. The spherical and the conical sections successively merge into each other. When the throttle is revolved, the conical surfaces are pressed against a valve seat (18) shaped as a circular ring made of steel. This seat then assumes a more and more elliptical shape finally to adjust itself entirely to the elliptical mean line of the seal face.