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.

A sleeve shaped valve cage for receiving a valve member is described. The valve cage can guide the valve member relative to the valve cage. The valve cage can include a throttle section configured to provide pressure-reduced flow rates of the processing fluid, the throttle section having multiple throttle conduits extending from an inside of the valve cage to an outside of the valve cage; a high capacity flow section adjacent to the throttle section in the displacement direction, the high capacity flow section configured to provide increased flow rates of the processing fluid; and at least one equalization channel formed in the valve cage and extending from the inside to the outside of the valve cage, the at least one equalization channel leading from the high capacity flow section to the throttle section such that, before the valve member releases all throttle conduits, the equalization channel is released.

The invention relates to a system and a method for injecting liquid odorant into a natural gas pipe, the system comprising: a tank containing the odorant in liquid form; a high-pressure pump connected to the tank; a common injection manifold fed with liquid odorant by the high-pressure pump; a plurality of odorant injectors fed with liquid odorant under pressure by the common injection manifold for the purpose of injecting the odorant into the gas pipe so as to cause it to be atomized in the gas pipe; and an electronic injection computer for controlling the injectors and the high-pressure pump.

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.

A control valve includes a valve body and a valve gate. The valve gate is movably located inside the inner space. The control valve has a lower flow rate limit which is greater than zero. That is, the lower flow rate limit has no necessary to be zero, thus it is acceptable to have a cylindrical valve gate but not a spherical valve gate, and a diameter of the cylindrical valve gate is be smaller than a caliber of an opening of the valve body. Therefore, the valve gate can be directly installed into the valve body via the opening, which allows the valve body to be made of a single piece so as to simplify the processes of manufacturing and assembly.

A sleeve shaped valve cage for receiving a valve member is described. The valve cage can guide the valve member relative to the valve cage. The valve cage can include a throttle section configured to provide pressure-reduced flow rates of the processing fluid, the throttle section having multiple throttle conduits extending from an inside of the valve cage to an outside of the valve cage; a high capacity flow section adjacent to the throttle section in the displacement direction, the high capacity flow section configured to provide increased flow rates of the processing fluid; and at least one equalization channel formed in the valve cage and extending from the inside to the outside of the valve cage, the at least one equalization channel leading from the high capacity flow section to the throttle section such that, before the valve member releases all throttle conduits, the equalization channel is released.