摘要:
A fluid flow control device includes a regulator for operating at high pressures and an integral bypass valve. The regulator and the bypass valve each include a control assembly that is movable between an open position and a closed position. The regulator and bypass valves are biased into the open positions and adapted to move into the closed positions when an operating pressure rises to above respective regulator and bypass set-point pressures. The bypass set-point pressure is lower than the regulator set-point pressure such that when the operating pressure rises above the bypass set-point pressure, the bypass valve automatically closes and allows the regulator to perform under normal operating conditions. So configured, the bypass valve is arranged to accommodate at least some of the fluid flow through the system until the operating pressure reaches the normal operating pressure, which is somewhere between the bypass and regulator set-point pressures.
摘要:
A pressure balanced solenoid operated valve includes a solenoid portion having a coil. A valve member portion is connected to the solenoid portion. The valve member portion has a body including: first and second valve seats; a first cavity positioned between the first valve seat and a valve outlet port. A valve member slidably disposed in the body has a resilient valve element positioned between the first and second valve seats, the resilient valve element when in direct contact with the first valve seat defining a valve closed position. A bleed port created in the body between the first valve seat and the valve outlet port and opening into the first cavity provides a flow path for a pressurized fluid present at the second valve seat in the valve closed position to continuously flow out through the valve outlet port.
摘要:
Methods and apparatus for bypassing a positioner in an active control loop are described. An example actuator assembly includes a pneumatic actuator and a transfer station. The transfer station includes a body defining flow paths that enable fluid to flow between a supply pressure, a valve positioner, and the pneumatic actuator and between the supply pressure and the pneumatic actuator to bypass the valve positioner without disrupting a process loop including the valve positioner. The transfer station also includes a plurality of fluid flow control devices to control the fluid flow through the flow paths.
摘要:
In some embodiments, a gas distribution apparatus may include: a manifold having a gas inlet to receive a process gas from a fast gas exchange unit and a first gas outlet to provide the process gas to a first gas delivery zone; a plurality of flow restrictors fluidly coupled to one another in parallel and to the gas inlet, wherein each of the plurality of flow restrictors are configured to allow at least a portion of a total flow of a process gas through each of the plurality of flow restrictors; and a plurality of valves each coupled to respective ones of the plurality of flow restrictors, wherein the plurality of valves are configured to be selectively opened to allow the process gas to flow through selective ones of the plurality of flow restrictors to provide a desired percentage of a total flow of the process gas to the outlet.
摘要:
Disclosed is an automatic pressure reducing valve. A body includes a hollow portion, an inlet portion and an outlet portion for flow of a fluid and has an internal space. A cylinder is installed inside the hollow portion and has at least two holes formed in its wall. An piston is movable along the inner side of the cylinder and adjusts opening rate of the holes according to a fluid pressure difference between an inlet portion and an outlet portion.
摘要:
A pressure control system remotely controls pressure within one or more remote zones, each respectively connected to an enclosure through a conduit, by controlling flow of a fluid into and out of each enclosure. The pressure of the fluid is measured within each enclosure. An estimated pressure within each zone is computed, as a function of the measured pressure in the enclosure and known characteristics of the conduit and the zone. For each zone, an inlet proportional valve and an outlet proportional valve of each enclosure is operated so as to control the input flow rate of the fluid into the respective enclosure and the output flow rate of the fluid out of the enclosure as a function of a pressure set point and the estimated pressure, thereby regulating pressure within the zone in accordance with the pressure set point.
摘要:
A variable flow rate controller is provided herein. The controller may have a linearly traversable switch such that the controller is primed to flush air bubbles out of the fluid system of the controller prior to administering fluidic medication to a patient. Moreover, the controller may have a plurality of valves which may be independently opened and closed by a caming surface. To close the valve, a first seal may be disposed between offset inlet and outlet to prevent fluid from flowing from the inlet to the outlet. To open the valve, the first seal is disposed on one side of both of the inlet and outlet. Fluid if permitted to flow from the inlet to the outlet.
摘要:
Disclosed is an automatic pressure reducing valve. A body includes a hollow portion, an inlet portion and an outlet portion for flow of a fluid and has an internal space. A cylinder is installed inside the hollow portion and has at least two holes formed in its wall. An piston is movable along the inner side of the cylinder and adjusts opening rate of the holes according to a fluid pressure difference between an inlet portion and an outlet portion.
摘要:
The inventive sliding valve (8) comprises a slide (18), which is mounted in a manner that enables it to move transversal to the passage channel (11). This valve is provided with an asymmetrical design whereby enabling the pressure prevailing in the passage channel (11) to reach a side of the slide (18) via suitable ducts (25, 26), whereas the other side is not subjected to any pressure or only to a constant low pressure. A pressure spring (29) works counter to the pressure and holds the slide (18) in the open position. In the event the fluid pressure prevails, the slide (18) is displaced into the blocking position in which it remains until the pressure falls below the switching limit once again.
摘要:
The inventive sliding valve (8) comprises a slide (18), which is mounted in a manner that enables it to move transversal to the passage channel (11). This valve is provided with an asymmetrical design whereby enabling the pressure prevailing in the passage channel (11) to reach a side of the slide (18) via suitable ducts (25, 26), whereas the other side is not subjected to any pressure or only to a constant low pressure. A pressure spring (29) works counter to the pressure and holds the slide (18) in the open position. In the event the fluid pressure prevails, the slide (18) is displaced into the blocking position in which it remains until the pressure falls below the switching limit once again.