Abstract: A flow limit valve for limiting the flow rate of a pressurized fluid includes a valve body with an interconnecting cavity of circular cross section. Within the cavity is a piston that slides within the cavity under force generated by a pressure differential across the piston to a closed position in engagement with a seat at the end of the cavity. A first encapsulated magnet is carried within the valve body in a chamber located on the side of the seat opposite the cavity. The first encapsulated magnet can be moved in response to another magnet outside the valve body to move a pin which can extend through the seat when the piston is in a closed position to thereby move the piston to an open position. The magnetic forces applied through the valve body affect internal valve operation via the pin and thus avoids the dange of noxious fluids escaping through sliding seals or flexible membranes.

Abstract: A flow limit valve for limiting the flow rate of a pressurized fluid includes a valve body with an interconnecting cavity of circular cross section. Within the cavity if a piston that slides within the cavity under force generated by a pressure differential across the piston to a closed position which prevents fluid flow through the valve. A pin is provided that is attached to the piston and that protrudes through the piston seat into the outlet side of the cavity when the piston is at the closed position. Opposite the pin is an encapsulated magnet within the valve body that can be moved in response to another magnet outside the valve body to contact the pin attached to the piston to move it to the open position. The magnetic forces applied through the valve body affect internal valve operation via the pin attached to the piston and this avoids the danger of noxious fluids escaping through sliding seals or flexible membranes.

Abstract: An improved flow-controlling mechanism utilizes interference-fitting components and static seals to assure accurate and repeatable fluid flow-controlling settings and to eliminate a leakage deteriorating seals.