Combination valve and regulation for use with pressurized gas cylinders, particularly oxygen cylinders

1. An apparatus for regulating the flow of a gas between a high-pressure zone and a zone of lower pressure, said apparatus comprising:

a hollow body having an axis;

a first chamber and a second chamber, said chambers defined within said body;

a nozzle within said body and separating said chambers, said nozzle comprising a convexly curved wall, and defining a passage for the passage of gas between said chambers; and

a stem movable axially within said passage and comprising:

a distal portion extending at least partially into said first chamber;

a proximate portion within said second chamber and extending into said passage, wherein axial movement of said stem varies the position of said proximate portion in relation to said nozzle; and

an o-ring seat between said proximate portion and said distal portion of said stem and contactable with said nozzle to seal said passage against the passage of gas.

2. An apparatus according to claim 1 wherein said curved wall is defined by a long radius arc and said nozzle comprises a minimum diameter.

3. An apparatus according to claim 2 wherein the ratio of said long radius to said nozzle minimum diameter is between approximately 2.53:1 and approximately 2.27:1.

4. An apparatus according to claim 2 wherein a diameter of said proximate portion of said stem is at least 98% of said nozzle minimum diameter.

5. An apparatus according to claim 4 further comprising means defined in said stem for providing gas flow area between said stem and said nozzle.

6. An apparatus according to claim 5 wherein said means for providing gas flow area comprises stem flow grooves defined in said proximate portion.

7. An apparatus according to claim 1 wherein said distal portion is removably connectable to said proximate portion of said stem and wherein, when connected, said distal portion and said proximate portion define an annular pocket for receiving said o-ring seat.

8. An apparatus according to claim 7 wherein said distal portion and said proximate portion have a screwed engagement, and wherein when fully engaged said distal portion and said proximate portion squeeze said seat and capture said seat within said pocket.

9. An apparatus according to claim 8 wherein less than one third of the toroidal circumference of said seat is exposed outside said pocket.

10. An apparatus according to claim 8 wherein said o-ring seat comprises an axial cross-sectional area, and said pocket defines an axial cross sectional area from about 7% to about 10% larger than said cross-sectional area of said seat, wherein when said seat is squeezed in said pocket a void is defined in said pocket between said seat and said stem.

11. An apparatus according to claim 10 further comprising a vent hole defined in said stem for providing fluid communication between said pocket and said second chamber for balancing pressures between said pocket and said second chamber.

12. An apparatus according to claim 10 wherein said seat comprises a polymer selected from the group consisting of PTFE Teflon® polymer, CTFE Neoflon® polymer, and Viton® polymer.

13. An apparatus according to claim 10 further comprising:

an axially directed guide hole defined between said body and said proximate portion of said stem; and

a guide pin inserted in said guide hole thereby to prevent rotation of said proximate portion around said axis.

14. An apparatus according to claim 1 further comprising means for regulating pressure in said second chamber.

15. An apparatus according to claim 14 wherein said means for regulating pressure comprises:

a spring flange movably disposed within said body;

a disk member positionally fixed within said body, said spring flange and said disk member defining there-between an interstage chamber; and

an axially symmetric shaft passing through a portal in said fixed disk and through said interstage chamber to separably connect said spring flange to said stem.

16. An apparatus according to claim 15 further comprising an internal seal for precluding fluid flow past said disk member.

17. An apparatus according to claim 16 further comprising a gasket seal on the distal side of said fixed disk for precluding fluid flow radially past said distal side.

18. An apparatus according to claim 17 further comprising a piston conduit for conveying pressure from said first chamber to a proximate end of said proximate stem portion.

19. An apparatus according to claim 18 further comprising a balancing conduit for conveying the fluid pressure from said second chamber and past said disk member to said interstage chamber.

20. An apparatus according to claim 19 further comprising a snap ring means, engageable with a circumferential grove in said body, for holding said disk member in position.

21. An apparatus according to claim 20 wherein said spring flange is separably connected to a proximate end of said axially symmetric shaft, thereby fixably connecting said spring flange to said stem.

22. An apparatus according to claim 21 further comprising:

a threaded barrel member defining a central portal in its bottom; and

an axial extension from said spring flange;

wherein said extension of said spring flange passes through said portal, and said extension is free to slide within the portal.

23. An apparatus according to claim 22 further comprising flexible biasing means disposed axially between said barrel and a proximal side of said spring flange, wherein controlled compression of said biasing means selectively adjusts the force balance on said spring flange, thereby regulating pressure in said second chamber.

24. An apparatus according to claim 1 wherein said proximate portion of said stem comprises a threaded means for separably attaching said stem to an adjustment handle, said threaded means comprising barrel means for containing thread wear debris.

25. An apparatus according to claim 24 wherein said proximate portion of said stem defines an external groove for mating with a non-rotational guide pin.

26. An apparatus according to claim 25 wherein said hollow body defines, adjacent said proximate stem portion, an internal groove for mating with a non-rotational guide pin.

27. An apparatus according to claim 26 further comprising a guide pin insertable through a top of said body for mating with said stem external groove and said body internal groove throughout the axial stroke of said stem.

28. An apparatus for regulating the flow of a gas between a high-pressure zone and a zone of lower pressure, said apparatus comprising:

a hollow body having an axis;

a first chamber and a second chamber, said chambers defined within said body;

a nozzle within said body and separating said chambers, said nozzle defining a passage for the passage of gas between said chambers;

a stem movable axially within said passage and comprising:

a distal portion extending at least partially into said first chamber;

a proximate portion within said second chamber and extending into said passage, wherein axial movement of said stem varies the position of said proximate portion in relation to said nozzle; and

an o-ring seat between said proximate portion and said distal portion of said stem and contactable with said nozzle to seal said passage against the passage of gas; and

means for regulating pressure in said second chamber, comprising:

a spring flange movably disposed within said body;

a disk member positionally fixed within said body, said spring flange and said disk member defining there-between an interstage chamber; and

an axially symmetric shaft passing through a portal in said fixed disk member and through said interstage chamber to separably connect said spring flange to said stem.

29. An apparatus according to claim 28 further comprising an internal seal for precluding fluid flow past said disk member.

30. An apparatus according to claim 28 further comprising a gasket seal on the distal side of said disk member for precluding fluid flow radially past said distal side.

31. An apparatus according to claim 28 further comprising a piston conduit for conveying pressure from said first chamber to approximate end of said proximate stem portion.

32. An apparatus according to claim 31 further comprising a balancing conduit for conveying the fluid pressure from said second chamber and past said disk member to said interstage chamber.

33. An apparatus according to claim 32 further comprising a snap ring means, engageable with a circumferential grove in said body, for holding said disk member in position.

34. An apparatus according to claim 32 wherein said spring flange is separably connected to a proximate end of said axially symmetric shaft, thereby fixably connecting said spring flange to said stem.

35. An apparatus according to claim 34 further comprising:

a threaded barrel member defining a central portal in its bottom; and

an axial extension from said spring flange;

wherein said extension of said spring flange passes through said portal, and said extension is free to slide within the portal.

36. An apparatus according to claim 35 further comprising flexible biasing means disposed axially between said barrel and a proximal side of said spring flange, wherein controlled compression of said biasing means selectively adjusts the force balance on said spring flange, thereby regulating pressure in said second chamber.

37. An apparatus for regulating the flow of a gas between a high-pressure zone and a zone of lower pressure, said apparatus comprising:

a hollow body having an axis;

a first chamber and a second chamber, said chambers defined within said body;

a nozzle defined by a convexly curved wall within said body and separating said chambers, said nozzle defining a passage for the passage of gas between said chambers; and

a stem movable axially within said passage and comprising:

a distal portion extending at least partially into said first chamber;

a proximate portion within said second chamber and extending into said passage, wherein axial movement of said stem varies the position of said proximate portion in relation to said nozzle;

stem flow grooves defined in said proximate portion for providing gas flow area between said stem and said nozzle; and

an o-ring seat between said proximate portion and said distal portion of said stem and contactable with said nozzle to seal said passage against the passage of gas.

38. An apparatus according to claim 37 wherein said curved wall is defined by a long radius arc and said nozzle comprises a minimum diameter.

39. An apparatus according to claim 38 wherein the ratio of said long radius to said nozzle minimum diameter is between approximately 2.53:1 and approximately 2.27:1.

40. An apparatus according to claim 38 wherein a diameter or said proximate portion of said stem is at least 98% of said nozzle minimum diameter.

41. An apparatus for regulating the flow of a gas between a high-pressure zone and a zone of lower pressure, said apparatus comprising:

a hollow body having an axis, said hollow body defining, adjacent said proximate stem portion, an internal groove for mating with a non-rotational guide pin;

an adjustment handle;

a first chamber and a second chamber, said chambers defined within said body;

a nozzle within said body and separating said chambers, said nozzle having a minimum diameter and defining a passage for the passage of gas between said chambers; and

a stem movable axially within said passage and comprising:

a distal portion having a diameter less than said minimum diameter of said nozzle, said distal portion extending at least partially into said first chamber;

a proximate portion, within said second chamber, removably connectable to said distal portion and extending into said passage, wherein axial movement of said stem varies the position of said proximate portion in relation to said nozzle;

wherein said proximate portion of said stem comprises a threaded means for separably attaching said stem to said adjustment handle, said threaded means comprising barrel means for containing thread wear debris and wherein further said proximate portion of said stem defines an external groove for mating with a non-rotational guide pin;

a guide pin insertable through a top of said body for mating with said stem external groove and said body internal above throughout the axial stroke of said stem; and

an o-ring seat between said proximate portion and said distal portion of said stem and contactable with said nozzle to seal said passage against the passage of gas.