The invention concerns a circuit intended to transfer, by means of a pump, first fluid, such as an aqueous urea solution, from a reservoir to an injector, said circuit also containing a second fluid, such as air, and said circuit comprising, downstream of the pump and of the reservoir, a downstream circuit portion which includes, on the one hand, a main branch which leads to the injector and, on the other hand, bypass branch which returns to the reservoir and which is provided with a double-seat valve designed to selectively and automatically adopt: purge configuration allowing to purge the second fluid through the valve out of the main branch, a pressurized supply configuration allowing to direct the first fluid to the injector under a predetermined working pressure, and a recirculation configuration allowing a recirculation through the bypass branch, and to the reservoir, of the first fluid coming from said reservoir.

The invention concerns a circuit intended to transfer, by means of a pump, first fluid, such as an aqueous urea solution, from a reservoir to an injector, said circuit also containing a second fluid, such as air, and said circuit comprising, downstream of the pump and of the reservoir, a downstream circuit portion which includes, on the one hand, a main branch which leads to the injector and, on the other hand, bypass branch which returns to the reservoir and which is provided with a double-seat valve designed to selectively and automatically adopt: purge configuration allowing to purge the second fluid through the valve out of the main branch, a pressurized supply configuration allowing to direct the first fluid to the injector under a predetermined working pressure, and a recirculation configuration allowing a recirculation through the bypass branch, and to the reservoir, of the first fluid coming from said reservoir.

Fluid control valve assemblies for use in fire protection sprinkler systems to control the flow of firefighting fluid to the system sprinklers. The assemblies include a pressure-operated fluid control valve having an internal fluid chamber in which fluid contained therein acts on an internal diaphragm to control the flow of fluid from an inlet to an outlet of the valve. An environment-responsive control device in fluid communication with the internal fluid chamber along a first fluid communication line controls the flow of fluid out of the fluid chamber to initiate actuation of the valve. A fluid-flow latch in fluid communication with the outlet of the valve along a second fluid communication line subsequently controls the simultaneous flow of fluid out of the fluid chamber and the actuation of the valve.

Fluid control valve assemblies for use in fire protection sprinkler systems to control the flow of firefighting fluid to the system sprinklers. The assemblies include a pressure-operated fluid control valve having an internal fluid chamber in which fluid contained therein acts on an internal diaphragm to control the flow of fluid from an inlet to an outlet of the valve. An environment-responsive control device in fluid communication with the internal fluid chamber along a first fluid communication line controls the flow of fluid out of the fluid chamber to initiate actuation of the valve. A fluid-flow latch in fluid communication with the outlet of the valve along a second fluid communication line subsequently controls the simultaneous flow of fluid out of the fluid chamber and the actuation of the valve.

A single-use centerbody assembly for a valve includes: a centerbody, including: a process surface and a back surface; at least one inlet orifice disposed in the centerbody, and at least one outlet orifice disposed in the centerbody separate from the at least one inlet orifice; a peripheral surface extending between the process surface and the back surface; an inlet fitting extending from the peripheral surface; and an outlet fitting extending from the peripheral surface; a control diaphragm facing the process surface, a perimeter of the control diaphragm being bonded to the centerbody so as to define a seal that blocks the passage of fluid; and a backside diaphragm positioned facing the back surface, a perimeter of the backside diaphragm being bonded to the centerbody so as to define a seal that blocks the passage of fluid.

A tray is provided between a supply air port member and an exhaust port member. A peripheral edge portion of an opening portion of an exhaust port of the exhaust port member that faces an output chamber side is a conical guiding portion. A spherical body is disposed between the guiding portion and an inner bottom face of a tray. The inner peripheral wall of the tray fits slidably into the outer peripheral surface of the end portion of the exhaust port member positioned within the output chamber. The other end of the poppet valve is caused to contact the outer bottom face of the tray. Thus, the exhaust port and the spherical body are centered automatically at the position of the center of the exhaust port, regardless of the position of the shaft axis of the poppet valve, so that there will be essentially no sliding friction.

A tray is provided between a supply air port member and an exhaust port member. A peripheral edge portion of an opening portion of an exhaust port of the exhaust port member that faces an output chamber side is a conical guiding portion. A spherical body is disposed between the guiding portion and an inner bottom face of a tray. The inner peripheral wall of the tray fits slidably into the outer peripheral surface of the end portion of the exhaust port member positioned within the output chamber. The other end of the poppet valve is caused to contact the outer bottom face of the tray. Thus, the exhaust port and the spherical body are centered automatically at the position of the center of the exhaust port, regardless of the position of the shaft axis of the poppet valve, so that there will be essentially no sliding friction.

A method, apparatus, and system for stopping a flow of a liquid coolant into, and drawing away a residual portion of the liquid, a portion of a cooling system, e.g., for resistance welding electrodes. The disclosed system does not require more than a single actuator, and in one case uses only a single actuator, coupled to both i) one or more liquid shutoff valves and ii) one or more liquid drawback apparatus. The liquid drawback apparatus draws on the liquid at approximately a same time that the one or more liquid shutoff valves shut off the flow of the liquid from the coolant supply. The liquid drawback apparatus includes a non-return check valve, disposed in the fluid passageway and biased against a normal flow of the liquid from the coolant supply.

A membrane valve for controlling flow and pressure relief, has a format following the anatomy and the action mechanism of a sphincter, in order not to have restriction points to the fluid flow. The valve includes a body provided with terminal sections provided with ends and, internally, a folded membrane which opens and closes according to the flow and/or pressure exerted therein, directly or indirectly, locally or remotely.

A membrane valve for controlling flow and pressure relief, has a format following the anatomy and the action mechanism of a sphincter, in order not to have restriction points to the fluid flow. The valve includes a body provided with terminal sections provided with ends and, internally, a folded membrane which opens and closes according to the flow and/or pressure exerted therein, directly or indirectly, locally or remotely.