Abstract: The present invention relates to a non-stagnant piping system and it is an object of this invention to provide a piping system such that the fluid inside the upstream side piping of a valve portion and inside the valve will not become stagnant in a super pure water line and chemical solution, etc., regardless of whether the valve is in a closed or opened state.A diaphragm valve 3 having a by-pass means 3b installed on the upstream side of the valve portion 3a is mounted in the sub-line 2 branched from the main line 1 in the piping system, and a pressure reducing unit 4 having a pressure reducing portion by a throttling portion 4a, and a by-pass 4b communicating with the throttling portion 4a is installed on the downstream side of the branch point with the sub-line 2 in the main line 1, and moreover, both by-pass means 3b and 4b communicate with each other.

Abstract: The present invention provides a control valve with an improved closing function that functions over a long period of time and the flow rate control can be carried out over a wide range.A valve body (1) is provided inside thereof with a partition (4) separating an inlet passage (2) and an outlet passage (3). The partition (4) is provided with an opening portion (5) communicating the inlet passage (2) and the outlet passage (3).A shutoff valve (10) is disposed opposite the opening portion (5). The diameter of the opening portion (5) is increased and curves toward the side of the shutoff valve (10).A control plug (12) is arranged on and projected from the lower end of the shutoff valve (10); said control plug being located on the large diameter side of the opening portion (5), is coaxial with the opening portion (5), and has a flange portion (12a) defining an orifice (14) between the inner surface of the opening portion (5) and the flange portion.

Abstract: In a ball valve wherein the rotation of a ball (1) provided in a valve chest (8) opens and closes a valve, an orifice (4) is provided in a passage (3) of the ball, and communicating passages (5) connecting the upstream side of the orifice (4) with the valve chest (8) and communicating passages (6) connecting the downstream side of the orifice with the valve chest (8) are provided. The passage (3) provided in the ball (1) has a large aperture at one end (30) and a small aperture at the other end (31), the respective communicating passages (5) (6) are formed so as to communicate the passage (3) with the valve chest (8) when the valve is opened, and the aperture of the passage (32) whereat a seat carrier (11) of the small aperture side of the ball faces the ball is made substantially the same as the aperture of the small aperture side end (31) of the passage of the ball (1).

Abstract: A constant flow valve comprises a valve body (5) having an inlet passage (2), an outlet passage (3), and a hollow chamber (4) disposed between the passages and inclined with respect to the inlet passage at a certain angle; an opening (7) for connecting the outlet passage with the hollow chamber, an inner circumferential face of the opening being tapered from an upstream side toward a downstream side; a lid body (17) fitted to the valve body; a spindle (9) supported by the lid body and movable back and forth along the axis of the opening; a cylinder (10) integrally arranged at a lower end of the spindle; a valve shaft (12) freely arranged inside the cylinder and positioned substantially on the axis of the opening; a valve plug (13) fitted to a front end of the valve shaft to create an orifice between itself and the opening; and springs (14, 15) disposed inside the cylinder to force the valve plug away from the opening.

Abstract: A constant flow valve comprising a valve casing having a flow passage having a curve due to a partition arranged between an inlet flow passage and an outlet flow passage, a chamber located above and between the inlet flow passage and the outlet passage, and an opening communicating the inlet flow passage with the chamber and tapered from the downstream side toward the upstream side; a cap attached to the valve casing and supporting a cylinder arranged coaxially with the opening and able to move forward and backward, and having a sealing surface at the lower end thereof which is pressed against a valve seat of the opening; a valve plug slidably fitted in the cylinder and having a through hole communicating with the opening, and arranged coaxially with the opening so that an orifice is always defined between the opening and the end of the valve plug; and a spring arranged between the valve plug and the cylinder, to bias the valve plug away from the opening.