A flow arrangement for a pressure relief valve assembly can include a bypass flow path extending from a pressure source to a dome of a relief valve. The bypass flow path can include a valve that is configured to open and close the bypass flow path based on pressure at the pressure source or the dome, or a pressure difference between the pressure source and the dome.

Apparatus for regulating gas pressure suitable for use in systems and/or networks for transport and/or distribution of gas, the apparatus configured to be connected upstream with an inlet duct for the gas and downstream with an outlet duct, and includes: a main regulator including: an inlet area fluidically connectable with the inlet, an outlet area fluidically connectable with the outlet, a shutter which acts between the inlet area and the outlet area, means configured to push the shutter towards a closed position, a motorization chamber in which a movable element is housed, a pilot regulator including: an inlet which is fluidically connected with a first sub-chamber, to thus allow the passage of gas from the first sub-chamber towards an inlet of the pilot regulator, an outlet which is fluidically connected to said second sub-chamber, and at least one pilot valve.

A flow arrangement for a control valve can include a plurality of flow-control components that are movable relative to each other and that define at least part of a flow path from a pressure source to a dome of a pressure relief valve. The flow-control components can be movable relative to each other in response to system pressure to selectively increase or decrease the flow capacity of the flow path. In some cases, flow capacity can be increased or decreased during initial loading of the dome, at low pressures, or at higher pressures.

A valve assembly is provided. The valve assembly includes a valve body defining a bore. The valve assembly further includes a pull rod disposed in the bore and defining a bolt cavity. The pull rod is moveable between a first pull rod position and a second pull rod position. The valve assembly further includes a bolt disposed in the bolt cavity and moveable with respect to the pull rod between a first bolt position and a second bolt position. The valve assembly further includes a spool disposed in the bore. The spool is operatively coupled to the pull rod to move between an energized position and a neutral position.

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 is provided. The device includes an upstream valve casing defining an inlet, a downstream valve casing defining an outlet aperture, and a valve core secured between the upstream valve casing and the downstream valve casing. The upstream valve casing, the downstream valve casing and the valve core are formed as discrete parts. The valve core includes a housing defining a control volume. The valve member is mounted on the housing and positioned on the upstream side of the outlet aperture, the valve member being arranged to move reciprocally to selectively open and close the outlet aperture, thereby controlling flow of the fluid through the outlet aperture.

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 an upstream valve casing defining an inlet, a downstream valve casing defining an outlet aperture, and a valve core secured between the upstream valve casing and the downstream valve casing. The upstream valve casing, the downstream valve casing and the valve core are formed as discrete parts. The valve core includes a housing defining a control volume. The valve member is mounted on the housing and positioned on the upstream side of the outlet aperture, the valve member being arranged to move reciprocally to selectively open and close the outlet aperture, thereby controlling flow of the fluid through the outlet aperture.

A fluid regulator includes an actuator assembly disposed in a valve body. A sleeve includes a cylindrical wall, a first plate, and a second plate. Each of the first plate and the second plate is disposed in a cavity of the sleeve. A stem extends through the sleeve and is axially aligned with a longitudinal axis of the body, and includes a passage extending partially through the stem. The actuator assembly includes first and second pistons. First, second, third, and fourth chambers are separately disposed between the sleeve, the first or second plate, or the first or second piston. The first and third chambers are in fluid communication, and the second and fourth chambers are in fluid communication via the passage of the stem. The actuator assembly actuates a control element in response to a fluid pressure receivable in the first, second, third, and/or fourth chambers.

Techniques for using data indicating if a gas regulator supplying gas at a regulated pressure to a gas meter (e.g., the gas meter of a house or business) within a gas distribution system has one or more lock-up failure events or venting events, wherein gas is vented to the atmosphere. The data may identify the identity of gas regulators at which the lock-up failure events or venting events occurred. Based at least in part on the identified gas regulators, a number of gas regulators having at least one of lock-up failure events or venting events that are connected to a same gas supply line may be identified. If the number of gas regulators having at least one of lock-up failure events or venting events on the identified gas supply line exceeds a threshold number this may indicate the presence of debris in the gas supply. Remedial steps may be taken, and the situation may be monitored and reassessed.

Blocking device for pressurized gas pipelines includes: a blocking valve, which includes: a connection body; a movable shutter; a stem carrying the shutter; a fluid-dynamic actuator, configured to translate the stem; thrust means to bring the shutter from an operating position of opening to an operating position of complete closure; a control system for controlled actuation of the fluid-dynamic actuator, having a by-pass group for equalizing upstream pressures in an upstream chamber and downstream pressures in a downstream chamber, and a pressure reducer group interconnected with the bypass group, the pressure reducer group configured to receive a motorization fluid at a supply pressure as input, and to supply the fluid-dynamic actuator with a motorization pressure through a motorization line, the control system having a pressure differential selector that detects a signal of the upstream pressure and a signal of the supply pressure.

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.