US 12,013,072 B2
Fluid shut-off system and shut-off method
Toshiyuki Sato, Shiga (JP)
Assigned to SUIKEN Co., Ltd., Shiga (JP)
Appl. No. 17/802,186
Filed by SUIKEN Co., Ltd., Shiga (JP)
PCT Filed Feb. 19, 2021, PCT No. PCT/JP2021/006294
§ 371(c)(1), (2) Date Aug. 25, 2022,
PCT Pub. No. WO2021/177055, PCT Pub. Date Sep. 10, 2021.
Claims priority of application No. 2020-037588 (JP), filed on Mar. 5, 2020.
Prior Publication US 2023/0081652 A1, Mar. 16, 2023
Int. Cl. F16L 55/105 (2006.01); B26D 3/16 (2006.01); F16K 3/02 (2006.01)
CPC F16L 55/105 (2013.01) [B26D 3/16 (2013.01); F16K 3/0281 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A shut-off system comprising a straight pipe made of a polyolefin-based material, and a flat plate-shaped knife gate that stops flow of fluid in the straight pipe, wherein:
a semicircular arc-shaped first cutting blade is formed on a distal end side of the knife gate to cut open the straight pipe to form a slit-shaped opening that extends elongated in a circumferential direction of the straight pipe;
an arc band-shaped sealing portion is formed on a proximal end side of the knife gate to be in contact with cut surfaces, of the straight pipe, the cut surfaces defining the opening;
the knife gate includes a pair of side edge portions, that connect the semicircular arc-shaped first cutting blade and the arc band-shaped sealing portion;
the semicircular arc-shaped first cutting blade and the pair of side edge portions, of the knife gate bite into an inner circumference surface of the straight pipe along the inner circumference surface;
the knife gate is formed in a flat plate shape having a first surface and a second surface opposite to the first surface,
the first surface and the second surface each extending from the first cutting blade to the sealing portion and between the pair of side edge portions;
the slit-shaped opening extends in the circumferential direction on the straight pipe; and
the sealing portion of the knife gate is formed in the arc band shape, extending from one end of the opening in the circumferential direction to another end of the opening, and extending from the inner circumference surface to an outermost surface, which is on an outermost side, of the straight pipe from the one end to the other end.