Hybrid flow and pressure regulation
An outlet assembly for hybrid pressure and flow regulation includes a first orifice of a first size, a second orifice of a second size that is larger than the first size, and a mechanism that automatically moves the first orifice between a first position, a second position, and a third position. When the first orifice is in the first position, the flow of gas passes through the first orifice, which regulates a flow rate of the flow of gas through the second orifice. When the first orifice is in the second position, the flow of gas primarily bypasses the first orifice and flows through the second orifice with a first specific flow rate. When the first orifice is in the third position, the flow of gas primarily bypasses the first orifice and flows through the second orifice with a second specific flow rate.
1 . An outlet assembly, comprising:
a housing defining an internal cavity;
a first orifice of a first size that is disposed proximate an upstream end of a main pathway that extends longitudinally through the internal cavity;
a second orifice of a second size that is larger than the first size disposed proximate a downstream end of the main pathway;
one or more first auxiliary pathways that are disposed between the first orifice and the second orifice and that intersect the main pathway;
one or more second auxiliary pathways that are disposed between the first orifice and the second orifice and that intersect the main pathway, wherein the one or more second auxiliary pathways are downstream from the one or more first auxiliary pathways; and
an internal mechanism that automatically moves the first orifice between a first position, a second position, and a third position, wherein the internal mechanism includes a movable poppet and the one or more second auxiliary pathways extend through the movable poppet, and wherein:
when the first orifice is in the first position, a flow of gas flowing through the outlet assembly flows into the main pathway via the first orifice so that the flow of gas flows through the second orifice at a first flow rate regulated by the first orifice;
when the first orifice is in the second position, the flow of gas primarily bypasses the first orifice and flows into the main pathway via the one or more first auxiliary pathways so that the flow of gas flows through the second orifice at a second flow rate regulated by the first orifice and the one or more first auxiliary pathways; and
when the first orifice is in the third position, the flow of gas primarily bypasses the first orifice and flows into the main pathway via the one or more first auxiliary pathways and the one or more second auxiliary pathways so that the flow of gas flows through the second orifice at a maximum flow rate.
2 . The outlet assembly of claim 1 , wherein
the movable poppet moves the first orifice between the first position, the second position, and the third position.
3 . The outlet assembly of claim 2 , wherein the housing defines the second orifice and the movable poppet defines the first orifice and the main pathway.
4 . The outlet assembly of claim 2 , wherein the internal mechanism comprises:
a first biasing member that is biased against the movable poppet to cause the movable poppet to retain the first orifice in the first position until backpressure in the outlet assembly reaches a first predetermined threshold;
a bypass poppet disposed around the movable poppet so that the movable poppet acts on the bypass poppet when the first orifice is in the second position; and
a second biasing member that is biased against the bypass poppet to cause the bypass poppet and the movable poppet to retain the first orifice in the second position until the backpressure in the outlet assembly reaches a second predetermined threshold.
5 . The outlet assembly of claim 4 , wherein the backpressure automatically moves the movable poppet so that the movable poppet moves the first orifice into the second position when the backpressure reaches the first predetermined threshold and so that the movable poppet moves the first orifice into the third position when the backpressure reaches the second predetermined threshold.
6 . The outlet assembly of claim 4 , further comprising:
a first annular passageway that is opened when the movable poppet moves the first orifice into the second position to allow the flow of gas to primarily bypass the first orifice, the first annular passageway providing a flow path to the one or more first auxiliary pathways; and
a second annular passageway that is opened when the movable poppet moves the bypass poppet, the second annular passageway providing a flow path to the one or more second auxiliary pathways.
7 . The outlet assembly of claim 1 , wherein the first orifice defines an upstream entrance for the main pathway.
8 . The outlet assembly of claim 1 , further comprising:
a first annular flange disposed radially exteriorly of the first orifice, proximate the upstream end of the main pathway, the first annular flange being configured to seal peripheral edges of a first backpressure chamber formed around the first orifice when the first orifice is in the first position and being configured to open the peripheral edges of the first backpressure chamber when the first orifice is in the second position; and
a second annular flange disposed radially exteriorly of the first annular flange, proximate the upstream end of the main pathway, the second annular flange being configured to seal peripheral edges of a second backpressure chamber formed around the first orifice when the first orifice is in the second position and being configured to open the peripheral edges of the second backpressure chamber when the first orifice is in the third position.
9 . An apparatus, comprising:
a cylinder; and
a cylinder fitting comprising the outlet assembly of claim 1 .
10 . The apparatus of claim 9 , wherein the cylinder fitting further comprises:
a gauge that provides a visual indication of both a flow rate and a pressure of the flow of gas exiting the outlet assembly.
11 . The apparatus of claim 9 , wherein the cylinder fitting includes an adjustment assembly configured to control a pressure of the flow of gas prior to the flow of gas entering the outlet assembly.
12 . The apparatus of claim 9 , wherein the cylinder fitting is irremovably coupled to the cylinder.
13 . The apparatus of claim 12 , wherein the cylinder is a refillable cylinder.
14 . A gas cylinder comprising:
a cylinder with a tank and an outlet; and
a hybrid pressure and flow fitting irremovably coupled to the outlet of the cylinder, the hybrid pressure and flow fitting including an outlet assembly comprising:
a housing defining an internal cavity extending from an upstream end to a downstream end;
a plug disposed within the internal cavity proximate the upstream end; and
a two-stage poppet disposed within the internal cavity between the plug and the downstream end of the internal cavity, the two-stage poppet including:
a first seat defining a central orifice;
a second seat disposed around the first seat;
a first biasing member that is biased against the first seat to cause the first seat to engage the plug until backpressure acting against the first seat reaches a first predetermined threshold, wherein disengaging the first seat from the plug opens a first flow path between the first seat and the second seat, the first flow path allowing gas to flow at a first flow rate that is greater than a flow rate allowed by the central orifice; and
a second biasing member that is biased against the second seat to cause the second seat to engage the plug until backpressure acting against the second seat reaches a second predetermined threshold, wherein disengaging the second seat from the plug opens a second flow path between the second seat and the housing, the second flow path allowing a gas to flow at a second flow rate that is greater than the flow rate allowed by the central orifice.
15 . The gas cylinder of claim 14 , wherein the backpressure acting against the second seat primarily acts against the second seat indirectly, by way of the first seat.
16 . The gas cylinder of claim 14 , wherein the second seat disengages from the plug after the first seat disengages from the plug so that the second flow path is open when the first flow path is also open.
17 . The gas cylinder of claim 16 , wherein, collectively, the second flow path and the first flow path allow gas to flow at a third flow rate that is greater than both the first flow rate and the flow rate allowed by the central orifice.
18 . The gas cylinder of claim 16 , wherein the cylinder is a refillable cylinder.
19 . The gas cylinder of claim 16 , wherein the hybrid pressure and flow fitting further comprises:
a pressure control;
an on/off control; and
a gauge.
20 . The gas cylinder of claim 19 , wherein the pressure control is aligned on a longitudinal axis of the tank of the gas cylinder and the on/off control and the gauge are oriented orthogonally to the longitudinal axis of the tank.