A mass flow control apparatus and methods for calibrating and tuning the mass flow apparatus are provided. The mass flow apparatus can be calibrated by receiving a calibration input signal that provides one or more properties of a gas that is flowing through a main fluid flow path and performing one or more measurements, using one or more sensors, on the gas. The calibration includes determining a calibration parameter based on the results of the one or more measurements and the calibration input signal and adjusting a proportional valve, based on the calibration parameter, to adjust a flow rate, of the gas through the apparatus, to match a setpoint flow rate.

Disclosed is an air mix valve including: a wall having at least three openings; and at least one airflow-regulating device. The airflow-regulating device includes: at least two shutters placed in the internal volume of the valve, at least one aerodynamic shutter of which is arranged with respect to one of the openings so as to be able to receive an airflow passing through this opening, and a linking mechanism between at least two shutters. Each of the shutters is arranged and guided so as to be able to be caused to move with respect to the wall. At least one airflow-regulating device, named aero-controlled regulation device, is mounted to be freely movable under the effect of aerodynamic energy from airflows passing through the openings.

A check valve includes a housing, a flap, a hinge, at least one post, and at least one tubular bumper. The hinge allows the flap to rotate relative to the housing between a fully open position and a closed position. The at least one post is disposed at or near the periphery of the housing supporting the hinge and extending axially relative to the housing from the housing. The at least one tubular bumper is movable with the flap and configured to contact the at least one post when the flap pivots to the fully open position.

A flow-controlling unit having a function of limiting the tilting angle of a flow-controlling piece which includes a flow-controlling plate, which is disposed perpendicular to the moving direction of a fluid in a flow channel. The flow-controlling plate includes first fluid through-holes through which the fluid passes and flow-controlling pieces which are provided in a part corresponding to the first fluid through-holes. The flow-controlling pieces are inclined in the direction of the inflow of the fluid and control the degree of opening of the first fluid through-holes by being tilted due to pressure applied from hydraulic pressure of the fluid. A tilting-angle-limiting plate has second fluid through-holes which communicate with the first fluid through-holes, wherein the diameter of the second fluid through-holes is smaller than the diameter of the first fluid through-holes, allowing the flow-controlling pieces to be supported to limit the tilting angle of the flow-controlling pieces.

A tuned mass system has a bulk mass acted upon by an excitation amplitude and a reaction mass coupled to the bulk mass. A resistance-to-motion controlled coupling mechanism associated with the reaction mass is configured to proportionally modulate independent of excitation force such that the relative phase of the bulk mass and the reaction mass is substantially constant throughout an extended range of excitation amplitude. The resistance-to-motion controlled coupling mechanism is a Variable Aperture Reciprocating Reed (VARR) Valve in one embodiment, and operates as a passive mechanism. In other embodiments, active resistance-to-motion controlled coupling mechanisms are employed.

An automatic airflow balancing valve, including: a housing having an inlet and an outlet and defining a flow path therethrough; a valve disc operatively connected to the housing and disposed within the flow path; and an airflow volume calibrating assembly disposed in the flow path and operatively connected to the valve disc and the housing to pivot the valve disc to a home position associated with a desired constant airflow volume. The airflow volume calibrating assembly may include an adjustment element that extends toward at least one of the inlet or the outlet.

An automatic airflow balancing valve, including: a housing having an inlet and an outlet and defining a flow path therethrough; a valve disc operatively connected to the housing and disposed within the flow path; and an airflow volume calibrating assembly disposed in the flow path and operatively connected to the valve disc and the housing to pivot the valve disc to a home position associated with a desired constant airflow volume. The airflow volume calibrating assembly may include an adjustment element that extends toward at least one of the inlet or the outlet.

Pivot valves have a valve seat and a valve closure mounted for pivoting movement through a closure chamber in a passage. The pivot valves may be selectively set in a check mode and an open mode. Flapper valves have a hydrofoil extending from a flapper. Valve assemblies comprise the pivot valves and flapper valves and have an open condition, a check condition, and a shut-off condition.

A ventilation flow rate regulator for a pressurised tank of a vehicle. The regulator includes a body including a gas inlet and a gas outlet, and at least one restrictor mounted movably relative to the body. The restrictor is mounted to reduce a cross-section of at least one path of a gas flow proceeding from the inlet to the outlet, when a flow rate at the inlet is greater than a predetermined threshold. The regulator is arranged so that the cross-section remains non-zero irrespective of a flow rate.

A closed concentrated dry chemical dispersion system including a closed ingredient container having a volume of dry ingredient therein. The system provides a fluid container and a mixing chamber in which the dry ingredient and fluid can be mixed to form a formulation for delivery to a device such as agrochemical dispensing equipment. The system minimizes worker exposure to the chemicals and enables lower packaging and transportation costs.