An additive manufacturing system can include a powder dispenser; a gate adjacent to the powder dispenser; a recoater blade system; and a control operable to move the gate with respect to the powder dispenser to selectively dispense powder from the powder dispenser.

A seal with a wedging element for adjustably compressing the seal. The seal abuts a surface, such as a gate of a gate valve, to seal against the surface with a sealing force that prevents fluid flow therebetween. The sealing force of the seal may be increasing or decreasing compression by adjusting the wedging mechanism. For example, as the seal wears away due to friction between the seal and a sliding gate, the compression may be increased in the wedging mechanism to increase the sealing force to a low threshold.

An additive manufacturing system can include a powder dispenser; a gate adjacent to the powder dispenser; a recoater blade system; and a control operable to move the gate with respect to the powder dispenser to selectively dispense powder from the powder dispenser.

A bidirectional gate valve including: a blade (200) installed in a valve housing (100) having first and second passage holes (110, 120) to open/close the first and second passage holes (110, 120); a shaft (300) coupled to a lower portion of the blade (200); a first driving block (400) including: a first cylinder (410) which is provided under the valve housing (100) and into which the shaft (300) is inserted; a first piston (420) installed inside the first cylinder (410) and coupled to a lower portion of the shaft(300) to vertically move the shaft (300) according to pressure change inside the first cylinder (410).

The present invention is characterized by including: a blade (200) installed in a valve housing (100) having first and second passage holes (110, 120) to open/close the first and second passage holes (110, 120); a shaft (300) coupled to a lower portion of the blade (200); a first driving block (400) including: a first cylinder (410) which is provided under the valve housing (100) and into which the shaft (300) is inserted; a first piston (420) installed inside the first cylinder (410) and coupled to a lower portion of the shaft (300) to vertically move the shaft (300) according to pressure change inside the first cylinder (410); and horizontal movement guide rollers (430, 430) respectively provided on both outer sides thereof to guide the horizontal movement of the blade 200; a second driving block 500 which is coupled to a lower portion of the first guiding block 400 so as to be vertically movable and which guides the horizontal movement of the blade 200 according to the vertical movement thereof such that the horizontal movement guide rollers (430, 430) are respectively inserted into both inner side surfaces the second driving block 500; a third driving block (600) provided under the second driving block 500 and having therein: first and second mounting parts (610, 620) provided as respective independent spaces; a second piston (611) provided to the first mounting part 610 and coupled to the second driving block 500 to vertically move the second driving block 500 according to pressure change inside the first mounting part (610); and a movement restricting member (621) which is installed to the second mounting part (620) so as to be vertically movable and restricts a downward movement of the second piston (611); and a main body bracket (700) provided under the valve housing (100) to accommodate the first, second, and third driving blocks (400, 500, 600).

An additive manufacturing system can include a powder dispenser; a gate adjacent to the powder dispenser; a recoater blade system; and a control operable to move the gate with respect to the powder dispenser to selectively dispense powder from the powder dispenser.

A gate valve for use in oil field applications and including a seat seal assembly. The seat seal assembly includes primary, secondary, and tertiary seals for sealing the space between the seat rings and the valve body. The provision of multiple seals in the seat seal assembly provides redundancy that allows for maintenance of the seal between the components even if one or two of the individual seals fail.