Systems for filling a gas cylinder
A flow control valve includes a housing defining a cavity therein. The housing has an input port for receiving a gas from a gas supply, and an output port for delivering the gas to a gas cylinder. The cavity defines a staging area fluidly connected to the input port, a delivery area fluidly connected to the output port, and a pressurization area fluidly connected to a feedback sensing port. The feedback sensing port is configured to receive pressurized fluid that is pressurized to a pressure level representative of a pressure level of gas delivered to the gas cylinder. The flow control valve includes a piston slidably positioned in a channel extending between the pressurization area and the delivery area. The position of the piston changes a rate of flow of gas through the flow control valve. The piston position moves in response to a pressure at the feedback sensing port.
1. A flow control valve (FCV) comprising:
a housing defining a cavity therein and a longitudinal axis, the housing having an input port for receiving a gas from a gas supply, and an output port for delivering the gas to a gas cylinder;
the cavity defining a staging area fluidly connected to the input port, a delivery area fluidly connected to the output port, and a pressurization area fluidly connected to a feedback sensing port, the feedback sensing port configured to receive pressurized fluid that is pressurized to a pressure level representative of a pressure level of gas delivered to the gas cylinder (P 2 ) and the input port configured to receive pressurized fluid that is pressurized to a pressure level representative of a pressure level of gas received from the gas supply (P 1 ), the cavity lying along the longitudinal axis of the housing with the staging area being between the pressurization area and the delivery area, the staging area, the delivery area, and the pressurization area being coaxial with the longitudinal axis of the housing;
a piston movably positioned in a channel, the channel extending through the cavity and along the longitudinal axis of the housing between the pressurization area and the delivery area, a position of the piston changing a rate of flow of gas through the flow control valve, the position of the piston moving in response to a pressure at the feedback sensing port, the piston moving within the channel toward the pressurization area to a minimum flow position when P 2 is less than P 1 ; and
a control spring within the pressurization area, the control spring engaging the piston and exerting a bias force on the piston to bias the piston toward an open position.
2. The flow control valve of claim 1 , further comprising an aperture situated between the delivery area and the staging area, and the piston further comprising a needle valve extending through the aperture, the needle valve configured to control the rate of flow of gas through the aperture.
3. The flow control valve of claim 2 , wherein the needle valve includes a tapered portion having a varying diameter such that a diameter at an end of the needle valve is less than a diameter of the aperture.
4. The flow control valve of claim 3 , wherein tapered region restricts a flow of the gas through the aperture when the piston is in the minimum flow position.
5. The flow control valve of claim 1 , further comprising an adjusting screw, the control spring having a proximal end engaging a flange of the piston and a distal end engaging the adjusting screw, the adjusting screw configured to exert an adjustable bias force on the flange.
6. The flow control valve of claim 1 , further comprising a pressure check assembly configured to maintain a greater pressure in the staging area than the pressurization area.
7. The flow control valve of claim 6 , wherein the pressure check assembly includes a pin and a return spring; the pin and return spring extending through a cavity in the piston; the return spring configured to extend based on a pressure in the feedback sensing port.
8. The flow control valve of claim 1 , wherein the input port, the output port, and the feedback sensing port are located at a first end of the flow control valve.
9. The flow control valve of claim 1 , wherein the housing includes a threaded portion configured to be mated to a port on a pneumatic control manifold.
10. The flow control valve of claim 1 , wherein the position of the piston is based on a pressure difference between a pressure in the staging area and the pressurization area.
11. A charging system comprising:
a storage cylinder configured to supply gas;
a gas cylinder configured to store gas;
a pneumatic control manifold (PCM) configured to receive a flow control valve, the PCM fluidly coupling the flow control valve to the storage cylinder and the gas cylinder; the flow control valve having:
a housing defining a cavity therein and a longitudinal axis, the housing having an input port for receiving a gas from the storage cylinder, and an output port for delivering the gas to the gas cylinder;
the cavity defining a staging area fluidly connected to the input port, a delivery area fluidly connected to the input port, and a pressurization area fluidly connected to a feedback sensing port, the feedback sensing port configured to receive pressurized fluid that is pressurized to a pressure level representative of a pressure level of gas delivered to the gas cylinder (P 2 ) and the input port configured to receive pressurized fluid that is pressurized to a pressure level representative of a pressure level of gas received from the storage cylinder (P 1 ), the cavity lying along the longitudinal axis of the housing with the staging area being between the pressurization area and the delivery area, the staging area, the delivery area, and the pressurization area being coaxial with the longitudinal axis of the housing;
a piston slidably positioned in a channel, the channel extending through the cavity and along the longitudinal axis of the housing between the pressurization area and the delivery area, a position of the piston changing a rate of flow of gas through the flow control valve, the position of the piston moving in response to a pressure at the feedback sensing port, the piston moving longitudinally within the channel toward the pressurization area to a minimum flow position when P 2 is less than P 1 ; and
a control spring within the pressurization area, the control spring engaging the piston and exerting a bias force on the piston to bias the piston toward an open position.
12. The flow control valve of claim 11 , further comprising an aperture situated between the delivery area and the staging area, and the piston further comprising a needle valve extending through the aperture, the needle valve configured to control the rate of flow of gas through the aperture.
13. The flow control valve of claim 12 , wherein the needle valve includes a tapered portion having a varying diameter such that a diameter at an end of the needle valve is less than a diameter of the aperture.
14. The flow control valve of claim 13 , wherein tapered region restricts a rate of the gas through the aperture when the piston is in the minimum flow position.
15. The flow control valve of claim 11 , further comprising an adjusting screw, the control spring having a proximal end engaging a flange of the piston and a distal end engaging the adjusting screw, the adjusting screw configured to exert an adjustable bias force on the flange.
16. The flow control valve of claim 1 , further comprising a pressure check assembly configured to maintain a greater pressure in the staging area than the pressurization area.
17. The flow control valve of claim 16 , wherein the pressure check assembly includes a pin and a return spring; the pin and return spring extending through a cavity in the piston; the return spring configured to extend based on a pressure in the feedback sensing port.
18. The flow control valve of claim 11 , wherein the input port, the output port, and the feedback sensing port are located at a first end of the flow control valve.
19. The flow control valve of claim 11 , wherein the housing includes a threaded portion configured to be mated to a port on the PCM.
20. The flow control valve of claim 11 , wherein the position of the piston is based on a pressure difference between a pressure in the staging area and the pressurization area.