A butterfly valve includes a valve body-side valve seat section, a valve box-side valve seat section, and a valve movement mechanism. The valve movement mechanism includes a cam groove, a cam projection, and a reverse key. The valve movement mechanism moves the valve body in an extending direction of the flow passage along with rotation of the valve shaft between a blocking position and an open position. One of the valve body-side valve seat section and the valve box-side valve seat section is formed of a laminated material composed of alternatingly stacked plates made of metal and plates made of expanded graphite.

A butterfly valve includes a valve body-side valve seat section, a valve box-side valve seat section, and a valve movement mechanism. The valve movement mechanism includes a cam groove, a cam projection, and a reverse key. The valve movement mechanism moves the valve body in an extending direction of the flow passage along with rotation of the valve shaft between a blocking position and an open position. One of the valve body-side valve seat section and the valve box-side valve seat section is formed of a laminated material composed of alternatingly stacked plates made of metal and plates made of expanded graphite.

A double eccentric valve includes a first bearing and a second bearing spaced apart from each other along a center axis of a rotary shaft. When a motor is operated and the valve element is at a controlled folly-closed position corresponding to a fully-closed state, the rotary shaft is inclined about the first bearing serving as a fulcrum and is out of contact with the second bearing. When a valve opening degree is a predetermined opening degree corresponding to a valve open state of the valve element, the rotary shaft is restrained by the second bearing. In a small opening range between the valve opening degree at the controlled fully-closed position and the predetermined small opening degree, a variation amount in open area relative to a variation amount in valve opening degree is smaller than that in an opening range larger than the predetermined opening degree.

A double eccentric valve includes a first bearing and a second bearing spaced apart from each other along a center axis of a rotary shaft. When a motor is operated and the valve element is at a controlled folly-closed position corresponding to a fully-closed state, the rotary shaft is inclined about the first bearing serving as a fulcrum and is out of contact with the second bearing. When a valve opening degree is a predetermined opening degree corresponding to a valve open state of the valve element, the rotary shaft is restrained by the second bearing. In a small opening range between the valve opening degree at the controlled fully-closed position and the predetermined small opening degree, a variation amount in open area relative to a variation amount in valve opening degree is smaller than that in an opening range larger than the predetermined opening degree.

A vacuum chamber (2) for a direct air capture process and enclosing an interior space (13) for housing an adsorber structure (1) is given comprising a contiguous circumferential wall structure (115) along an axis (15), which circumferential wall structure (115) in an axial direction is closed by an inlet and an outlet axial wall (116), respectively. Both axial walls (116) comprise at least one closing stainless steel lid (6) allowing for, in an open position, gas to be circulated through the vacuum chamber (2) for passing an adsorber structure (1), and, in a closed position, to close the interior space (13) and to allow evacuation of the interior space (13) down to pressure of 500 mbar.sub.abs or less.

A vacuum chamber (2) for a direct air capture process and enclosing an interior space (13) for housing an adsorber structure (1) is given comprising a contiguous circumferential wall structure (115) along an axis (15), which circumferential wall structure (115) in an axial direction is closed by an inlet and an outlet axial wall (116), respectively. Both axial walls (116) comprise at least one closing stainless steel lid (6) allowing for, in an open position, gas to be circulated through the vacuum chamber (2) for passing an adsorber structure (1), and, in a closed position, to close the interior space (13) and to allow evacuation of the interior space (13) down to pressure of 500 mbar.sub.abs or less.

An eccentric valve has a drive mechanism, a drive force receiving part, a bearing for supporting a rotary shaft, and a return spring for generating a return spring force. During non-operation of the drive mechanism, the eccentric valve generates a separating-direction urging force to cause the rotary shaft to incline about the bearing serving as a fulcrum and urge the valve element in a direction away from the valve seat, the separating-direction urging force being a force caused by the return spring force. Either the valve element or the valve seat is provided with a sealing member to seal between the valve element and the valve seat during non-operation of the drive mechanism.

Provided is a valve, comprising a valve body (10), a valve rod (30), a valve seat (50, 60), and a valve core assembly (20). The valve core assembly (20) is mounted inside the valve body (10) and comprises a valve core (21). The valve core (21) is articulated to the valve body (10), and the valve core assembly (20) further comprises a drive member (22), a positioning member (24), and a flexible member (23). The positioning member (24) is mounted on the valve core (21) such that it may move relative to same. The flexible member (23) is mounted between the positioning member (24) and the valve core (21); thus the drive member (22) has a separable fitting relationship with the positioning member (24), such that the valve has three drive relationships while it is being closed: that is, the drive member (22) fits with the positioning member (24) to form a relatively static first transmission relationship; a second transmission relationship in which the drive member (22) presses the positioning member (24) to cause the positioning member (24) to move relative to valve core; the second transmission relationship between the drive member (22) and the positioning member (24) is switched to a third transmission relationship between the drive member (22) and the valve core (21). The valve has the advantages of few component parts, a simple manufacturing process, a simple structure, and good utilization of space.

An erosion prevention structure for a sealing surface of a valve includes a valve body, a valve seat, a valve core, a valve sleeve and a valve rod. A valve seat mounting hole is provided in the valve body and located between a medium outlet and a cavity; the valve seat is arranged in the valve seat mounting hole; the top surface of the valve seat is provided with an annular table; the outside surface of the annular table is a sealing surface A, wherein an included angle is formed between the sealing surface A and a horizontal surface; an annular flange is arranged at the bottom of the valve core and located at the outer side of the valve core; the inside surface of the annular flange is a sealing surface B, wherein an included angle is formed between the sealing surface B and a horizontal surface.

An erosion prevention structure for a sealing surface of a valve includes a valve body, a valve seat, a valve core, a valve sleeve and a valve rod. A valve seat mounting hole is provided in the valve body and located between a medium outlet and a cavity; the valve seat is arranged in the valve seat mounting hole; the top surface of the valve seat is provided with an annular table; the outside surface of the annular table is a sealing surface A, wherein an included angle is formed between the sealing surface A and a horizontal surface; an annular flange is arranged at the bottom of the valve core and located at the outer side of the valve core; the inside surface of the annular flange is a sealing surface B, wherein an included angle is formed between the sealing surface B and a horizontal surface.