Provided is a flow rate controller. The flow rate controller calculates a resistor flow rate that is a flow rate of a fluid flowing through a fluid resistor, on the basis of a first measured pressure measured by a first pressure sensor and a second measured pressure measured by a second pressure sensor; controls a second valve on the basis of a deviation of the resistor flow rate from the set flow rate; outputs a first set pressure that is a target of a pressure upstream of the fluid resistor, on the basis of the set flow rate and a second set pressure which is a target of a pressure downstream of the fluid resistor and to which a constant value is set; and controls the first valve on the basis of a deviation of the first measured pressure from the first set pressure.

A method of mixing at N gases is provided. This method includes providing N gas flow meters, including N gas flows, wherein N is 3 or more. Measuring each of the N gas flows, at first predetermined intervals of time, and totaling each of the measured N flows over a second predetermined interval of time. Adding the N measured gas flows, thereby determining the total gas flow at the second predetermined interval of time. Dividing the total gas flow for each of the N gas flows by the total gas flow, thereby determining a cumulative calculated theoretical percentage for each of the N gas flows over the second predetermined interval of time. And sounding an alarm, and/or terminating the N gas flows, if the cumulative calculated theoretical percentage for any of the N gas flows exceeds a predetermined range value.

Another method of mixing at least two gases is provided. This method includes providing a mixture composition control, comprising a predetermined composition input and a composition trim input. Providing N gas flow meters, wherein N is 3 or more. Configuring the N flow meters to adjust the N gas flows to maintain the line pressure at a predetermined value, while maintaining the predetermined composition. Adding the N measured gas flow, thereby determining the total gas flow at the first predetermined intervals of time. Adjusting the composition trim input to vary the composition of the mixed gas, without modifying the predetermined composition input. And sounding an alarm, and/or terminating both the N gas flows, if either of the following exceed a predetermined range value: the instantaneous calculated theoretical percentage for any of the N gas flows, or the cumulative calculated theoretical percentage for any of the N gas flows.

Disclosed herein are inexpensive, easy-to-install (do-it-yourself/DIY), non-invasive, independently powered automated devices, apparatuses, systems and methods for leak detection, prevention and mitigation, particularly fluid leak detection, prevention and mitigation, as well as water leak detection and water-supply shutoff of domestic and commercial pressurized water-supply networks.

Metering devices for an agricultural implement are provided for applying a field input, for example, pneumatically delivered granular product including seed or fertilizer or sprayed liquid product including fertilizer and the like, to an agricultural field. In the applying of the field input, the rate of application of the dispensers of one section of the implement can be collectively varied in relation to the rate of application of the dispensers of a different section of the implement frame.

A starter air valve (SAV) system can include a pressure actuated SAV actuator configured to be operatively connected to a SAV and a first pressure valve configured to selectively allow pressure from a pressure source to the SAV actuator when in fluid communication with the SAV actuator. The first pressure valve can be a pulse-width modulation solenoid valve configured to provide a duty cycle of pressure from the pressure source to the SAV actuator.

A method of mixing at least two gases is provided. This method includes providing a mixture composition control, including a predetermined composition input and a composition trim input. Providing N gas flow meters, including a N gas flows, and N desired gas flow rates determined by the mixture composition control, wherein N is 3 or more. Mixing the N gas flows, thereby producing a mixed gas flow at the predetermined composition and at a line pressure. Configuring the N flow meters to adjust the N gas flows to maintain the line pressure at a predetermined value, while maintaining the predetermined composition. And adjusting the composition trim input to vary the composition of the mixed gas, without modifying the predetermined composition input.

A flow node includes characterized restrictor in series and adjacent with a valve to provide a primary flow restriction with a minimized volume between the two. A conductance of the characterized restrictor is low enough relative to the valve seat to cause a pressure drop that is sufficiently large relative to the pressure drop across the valve seat that a pressure measurement device is located upstream of the valve is used to determine the pressure to the inlet of the restrictor. A vent can be included to reduce bleed time. Multiple flow nodes in parallel increase a dynamic range.

A reference volume for use with pressure change flow rate measurement apparatus has an internal structure comprising elements with cross section and length comparable to the cross section and length of adjacent interstitial fluid regions. The reference volume may have one or more heat conduction elements exterior to and in good thermal contact with a corrosion resistant material that defines the internal fluid holding region.

The present disclosure provides a system and method for odorizing natural gas flowing through a distribution pipeline. The system includes a bypass line adjacent to a distribution pipeline, wherein bypass gas flows through the bypass line and an odorant tank connected to the bypass line, and into the distribution pipeline; a high-flow control valve and a low-flow control valve in the bypass line, wherein bypass gas flows through the odorant tank into the distribution pipeline when the high-flow control valve or the low-flow control valve is open; and a programmable logic controller connected to the high-flow and low flow control valve; wherein the programmable logic controller opens the high-flow or low-flow control valve for a predetermined dwell time proportional to an amount of bypass gas needed to odorize gas in the distribution pipeline each time that a preselected quantity of gas flows through the distribution pipeline.