A fluid flow control system serving as an inflow port from a fluid reservoir (R) to the interior of a production pipe (S) is in the form of a housing (3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l). The housing has a primary flow path (18) and a secondary flow path (19). The secondary flow path is in fluid communication with a chamber (B) in which is arranged an actuator (5) for a valve device (4), the valve device arranged to open and close the primary flow path. At least one flow restrictor (1,2) is arranged in the secondary flow path, the flow restrictor arranged to provide a pressure to chamber (B) sufficient to actuate the valve to an open position when the fluid flowing through the secondary flow path is oil, and a pressure sufficient to actuate the valve to a closed position when the fluid has a viscosity and/or density less than oil.

A throttle valve includes a throttle valve element; a support member that supports the throttle valve element, the support member including a valve element support portion, and a shaft portion that is connected to the valve element support portion, the shaft portion having a gas passage and an inlet port; a mounting member that mounts the support member in a throttle valve flow passage; a filter that is disposed on an outer peripheral surface of the shaft portion to cover the inlet port, in a space whose axial length is defined by the shaft portion and the mounting member; and gaskets that are respectively disposed between one axial end of the filter and the mounting member and between the other axial end of the filter and the shaft portion.

An apparatus for allowing the repetitive oscillation of pressure in a container or vessel having a finite volume. The apparatus comprises a valve having first opening, a valve enclosure having a second opening, and a first tension device. In some embodiments the apparatus can have a chamber capable of oscillating in volume. The oscillation of the chamber volume causes a decrease in the pressure of the container. As the pressure of the space or container decreases, two openings of the apparatus become more proximate. Eventually the openings partially overlap, allowing a gas, or fluid, to enter the container, increasing pressure of the space or container. As a result of the pressure increase, the first opening and second opening become less proximate by a force of the first tension device. The apparatus can allow the container to approach substantially perfect vacuum and rise toward atmospheric pressure.

A fluid flow control device serving as an inflow port from a fluid reservoir (R) to the interior of a production pipe (S) is in the form of a housing (3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l). The housing has a primary flow path (18) and a secondary flow path (19). The secondary flow path is in fluid communication with a chamber (B) in which is arranged an actuator (5) for a valve device (4), the valve device arranged to open and close the primary flow path. At least one flow restrictor (1,2) is arranged in the secondary flow path, the flow restrictor arranged to provide a pressure to chamber (B) sufficient to actuate the valve to an open position when the fluid flowing through the secondary flow path is oil, and a pressure sufficient to actuate the valve to a closed position when the fluid has a viscosity and/or density less than oil.

A check valve comprises a valve housing defining a pair of valve openings, a pair of flappers pivotably mounted for rotation relative to the housing between an open position in which they permit fluid flow through the respective valve openings and a closed position in which they prevent fluid flow through the valve openings, and a stop pin extending across the valve such that the flappers will contact the stop pin in their open positions. Each flapper comprises a primary flapper element and a secondary flapper element, each pivotally mounted to a hinge pin extending across the valve. The primary flapper element further comprises a flapper opening formed therethrough. The secondary flapper element is pivotally mounted to the hinge pin such that it may rotate relative to the primary flapper element for opening or closing the flapper opening.

A fluid flow control device includes a housing having a fluid inlet (7) and at least one fluid outlet (8). A first fluid flow restrictor (1) serves as an inflow port to a chamber (B) in the housing, and a second fluid flow restrictor (2) serves as an outflow port from the chamber (B). The first fluid flow restrictor and the second fluid flow restrictor are configured to generate different fluid flow characteristics; and the chamber (B) includes an actuating device (5a-1) that is responsive to fluid pressure changes (P.sub.2) in the chamber. The first fluid flow restrictor (1) and the second fluid flow restrictor (2) are configured to impose respective different fluid flow characteristics based on different fluid properties.

A check valve comprises a valve housing defining a valve opening and a web extending across the valve opening. First and second mounting posts are provided on the valve housing on opposite sides of the opening and extend away from the opening. Each mounting post has a transverse bore formed therein.

A check valve comprises a valve housing defining an opening and a plurality of flapper elements each having a proximal end and a distal end, the flapper elements being pivotally mounted to the valve housing at their proximal ends for pivotal movement between a closed position, in which they block the flow of fluid through the opening and an open position in which they permit the flow of fluid through the opening. Each flapper element is generally triangular or trapezoidal in shape such that the flapper elements create a generally conical or frustoconical shape when in the closed position.

The invention relates to an electromagnetically actuatable gas valve for metering a gaseous fuel into a suction tract of a motor, in particular a gas or diesel gas motor, comprising a valve seat (1) which is designed as a flat seat and which has multiple annular webs (3) that are arranged in a concentric manner and are connected via at least one radially running web (4) in order to delimit circular or semicircular through-flow openings (2). The electromagnetically actuatable gas valve further comprises a movable valve plate (5) which sealingly interacts with the valve seat (1) and which has multiple annular sealing webs (6) that are arranged in a concentric manner and can be brought into an overlapping arrangement with the circular or semicircular through-flow openings (2) of the valve seat (1). According to the invention, the rigidity of the valve seat (1) and/or the valve plate (5) is substantially constant in the radial direction, the rigidity of the valve seat (1) being greater than the rigidity of the valve plate (5). The invention further relates to a method for increasing the seal of an electromagnetically actuatable gas valve.

A check valve with a housing and a first flapper rotatable about an axis between open and closed positions includes a first spring mechanism operatively positioned between a static component and the first flapper. When the first flapper is in the closed position there is a distance between the first spring mechanism and either the static component or the first flapper.