A regulator includes a valve body and a control element movable between a closed position, in which the control element engages a valve seat, and an open position, in which the control element is spaced away from the valve seat. A stem is operatively coupled to the control element and is axially aligned with a longitudinal axis of the valve body. An indicator assembly is at least partially disposed in the valve body and is operatively coupled to the stem. The indicator assembly includes a rod operatively coupled to the stem and an indicator operatively coupled to the rod. The indicator is arranged to display a position of the control element. The rod of the indicator assembly is movable by the stem between a first position when the control element is in the closed position, and a second position when the control element is in the open position.

A hose end regulator for regulating pressure in fluid includes a main body having a fluid inlet and fluid outlet. A poppet moves between an open position to permit fluid to flow through the fluid outlet and a closed position to militate against fluid flowing through the fluid outlet. A primary spring permits the poppet to move between the open position and the closed position. A flow maximizer minimizes movement of the primary spring until a predetermined fluid pressure is reached within the main outer body.

A gas regulator includes a valve chamber body that houses two valves of the regulator. Valve elements that move to open and close the two valves are received via a same opening into the valve chamber body, which is closed by a plug. The plug can define a first valve seat as well as a piercing element used to pierce a compressed gas cylinder. A retainer can hold a gasket at a valve seat as well as provide a bore or other support for a valve element and valve element spring.

A pressure regulator for a fuel cell system may include: a housing having an inlet port into which gas is introduced, an outlet port through which gas is discharged, and an regulated pressure chamber connected to an outside through the outlet port; a piston moving up and down in the housing, having a main flow path penetrating through an inside of the housing and a pressure acting portion applying a pressure of gas in the regulated pressure chamber of the housing, and selectively communicating between the inlet port and the regulated pressure chamber of the housing through the main flow path as the piston moves up and down; and a spring provided in the housing to elastically support the pressure acting portion of the piston on an opposite side of the regulated pressure chamber.

A device is provided for controlling the flow of a fluid through a conduit from an upstream side to a downstream side of the device. The device includes a valve aperture, a cylindrical mounting member on the downstream side of the valve aperture, a valve member on the outside of the cylindrical mounting member that moves reciprocally to open and close the valve aperture, a control volume defined between the cylindrical mounting member and the valve member, an arrangement for introducing a control pressure into the control volume, and a seal between the outer surface of the cylindrical mounting member and the inner surface of the valve member that substantially seals the control volume. The valve member is acted on by the pressure of the upstream side (P.sub.1) and the control pressure (P.sub.4) so as to be moved by the difference between these pressures.

A pressure regulator includes a piston assembly having a primary piston, secondary piston, and valve seat positioned inside an internal chamber divided into a primary chamber and a secondary chamber, such that the primary piston and valve seat are positioned inside the primary chamber and the secondary piston is positioned inside the secondary chamber, where the piston assembly moves longitudinally along the axis of the internal chamber in response to the pressures exerted on the primary piston and valve seat by a working liquid flowing into the primary chamber, and where a supplemental fluid is selectively introduced into the secondary chamber to exert a force on the secondary piston to modify the longitudinal movement of the piston assembly and thereby regulate flow of the working fluid through the primary chamber.

A regulator may be configured to reduce an individual difference between products due to a size tolerance of each of a valve seated seat holding member, a valve seated seat, a piston pressure regulating valve, and a main body part. The main body part may be affected by a load of a pressure regulating spring, or a load variation at a set point of the pressure regulating spring. The regulator may be configured without a function loss due to a damage, leakage failure, or the like of the valve seated seat. A pressure regulating valve body 5 may be closely in contact with a valve seated seat 31, and a piston unit 6 that is formed around an outer periphery thereof and that affects a pressure regulating spring 8 are formed separately, the two forming a piston pressure regulating valve 7.

A hose end regulator for regulating pressure in fluid includes a main body having a fluid inlet and fluid outlet. A poppet moves between an open position to permit fluid to flow through the fluid outlet and a closed position to militate against fluid flowing through the fluid outlet. A primary spring permits the poppet to move between the open position and the closed position. A flow maximizer minimizes movement of the primary spring until a predetermined fluid pressure is reached within the main outer body.

A pressure regulator for a fuel cell system may include: a housing having an inlet port into which gas is introduced, an outlet port through which gas is discharged, and an regulated pressure chamber connected to an outside through the outlet port; a piston moving up and down in the housing, having a main flow path penetrating through an inside of the housing and a pressure acting portion applying a pressure of gas in the regulated pressure chamber of the housing, and selectively communicating between the inlet port and the regulated pressure chamber of the housing through the main flow path as the piston moves up and down; and a spring provided in the housing to elastically support the pressure acting portion of the piston on an opposite side of the regulated pressure chamber.

A device for controlling the flow of a fluid through a conduit from an upstream side of the device to a downstream side of the device. The device includes a valve aperture (30), a cylindrical mounting member (24) on the downstream side of the valve aperture, a valve member (26) on the outside of the cylindrical mounting member that moves reciprocally to open and close the valve aperture, a control volume (44) defined between the cylindrical mounting member and the valve member, an arrangement (8) for introducing a control pressure into the control volume, and a seal (34) between the outer surface of the cylindrical mounting member and the inner surface of the valve member that substantially seals the control volume. The valve member is acted on by the pressure of the upstream side (PI) and the control pressure (P4) so as to be moved by the difference between these pressures.