Charging port for pressure vessel

1. A pressure vessel, comprising:

a chamber;

a rubber disk;

a passageway extending from an exterior wall of the pressure vessel to the chamber;

a one-way valve disposed in the passageway, the one-way valve being normally closed and in fluid communication with the chamber; and

a plug disposed within the passageway, the plug coupled to the pressure vessel and accessible from outside of the pressure vessel,

wherein the passageway includes a first section, a second section, and a third section, the passageway extends through a first end cap, the second section is interposed directly between the first section and the third section, the first section extends from an interior wall of the first end cap to the second section and is in fluid communication with the chamber, the third section extends from an exterior wall of the first end cap to the second section,

wherein the second section is narrower in width than both the first and third sections, and

wherein the rubber disk is disposed in the third section between the plug and the one-way valve so that the plug compresses the rubber disk against a seat in the third section to form a fluid seal that prevents the fluid from flowing from the second section into the third section.

2. The pressure vessel of claim 1 , wherein an end of the plug is substantially flush with the exterior wall of the pressure vessel.

3. The pressure vessel of claim 1 , wherein an end of the plug is recessed in the passageway relative to the exterior wall, and further wherein the end faces away from the one-way valve when the plug is disposed within the passageway.

4. The pressure vessel of claim 1 , wherein the one-way valve comprises a check valve.

5. The pressure vessel of claim 4 , wherein the plug comprises a set screw.

6. The pressure vessel of claim 5 , wherein the plug comprises a socket to receive a tool.

7. An apparatus, comprising:

a pressure vessel comprising an interior chamber and a charging port, the charging port comprising:

a passageway extending from an exterior of the pressure vessel to the chamber;

a rubber disk;

a plug disposed in the passageway and coupled to the pressure vessel; and

a one-way valve disposed in the passageway between the interior chamber and the plug, wherein the charging port enables fluid to be supplied to the interior chamber when the plug is removed from the passageway and the one-way valve is in an open position,

wherein the passageway includes a first section, a second section, and a third section, the passageway extends through a first end cap, the second section is interposed directly between the first section and the third section, the first section extends from an interior wall of the first end cap to the second section and is in fluid communication with the chamber, the third section extends from an exterior wall of the first end cap to the second section,

wherein the second section is narrower in width than both the first and third sections, and

wherein the rubber disk is disposed in the third section between the plug and the one-way valve so that the plug compresses the rubber disk against a seat in the third section to form a fluid seal that prevents the fluid from flowing from the second section into the third section.

8. The apparatus of claim 7 , wherein the pressure vessel is an accumulator.

9. The apparatus of claim 7 , wherein the one-way valve is a check valve.

10. The apparatus of claim 9 , wherein the check valve comprises a ball, the ball to move toward the chamber to move from a closed position to the open position.

11. The apparatus of claim 7 , wherein the entire one-way valve is disposed within the passageway.

12. The apparatus of claim 11 , wherein the entire plug is disposed within the passageway.

13. A system, comprising:

a pressure vessel including a chamber, a passageway extending from an exterior wall of the pressure vessel to the chamber, and a one-way valve disposed in the passageway, the one-way valve being normally closed and in fluid communication with the chamber;

a rubber disk;

a plug to be disposed within the passageway and removably coupled to the pressure vessel, and

an adapter to be disposed within the passageway when the plug is removed from the passageway, the adapter configured to move the one-way valve from a closed position to an open position,

wherein the passageway includes a first section, a second section, and a third section, the passageway extends through a first end cap, the second section is interposed directly between the first section and the third section, the first section extends from an interior wall of the first end cap to the second section and is in fluid communication with the chamber, the third section extends from an exterior wall of the first end cap to the second section,

wherein the second section is narrower in width than both the first and third sections, and

wherein the rubber disk is disposed in the third section between the plug and the one-way valve so that the plug compresses the rubber disk against a seat in the third section to form a fluid seal that prevents the fluid from flowing from the second section into the third section.

14. The system of claim 13 , wherein the adapter includes a fitting configured to couple to a fluid line.

15. The system of claim 14 , wherein the adapter includes a pin to contact the one-way valve when the adapter is disposed within the passageway.

16. The system of claim 14 , wherein the adapter includes a fluid passageway to fluidly couple the chamber to the fitting when the adapter is disposed within the passageway.

17. The system of claim 13 , wherein the adapter is configured to move a portion of the one-way valve toward the chamber in order to move the one-way valve from the closed position to the open position.

18. The system of claim 13 , wherein the entire plug is disposed in the passageway when the plug is coupled to the pressure vessel.

19. The pressure vessel of claim 13 , wherein the one-way valve comprises a check valve.

20. The pressure vessel of claim 13 , wherein the plug comprises a set screw.