Ball valve with single piece packing

• US 20060255304A1
• Filed: 10/11/2005
• Published: 11/16/2006
• Est. Priority Date: 01/18/2002
• Status: Abandoned Application

• Current Assignee: Swagelok Company
• Original Assignee: Swagelok Company
• Inventors: Kvarda, Eric M., Gotch, James E., Timko, Jared S., Fry, Brandon J., Lippucci, Thomas A.
• Application Number:
  US11/247,353
• Publication Number:
  US 20060255304A1
• Time in Patent Office: Days
• US Class Current: 251/315.10
• CPC Class Codes: F16K 11/0873 the plug being only rotatable around one spindle
• CPC Class Codes: F16K 27/067 with spherical plugs
• CPC Class Codes: F16K 5/0636 the spherical plug being insertable from the top of the housing
• CPC Class Codes: F16K 5/0668 Single packings
• CPC Class Codes: F16K 5/0684 on the plug
• CPC Class Codes: F16K 5/0689 between housing and plug
• CPC Class Codes: F16K 5/0694 Spindle sealings
• CPC Class Codes: Y10T 137/0508 Ball valve or rotary ball valve

Abstract

A ball valve includes a valve element and a single piece packing that seals the valve element within a valve cavity. The single piece packing is installed over the valve element at room temperature or may be molded thereon. The valve element may include a flow control element such as a ball and upper and lower trunnions. The various dimensions of the valve element and packing are selected to facilitate room temperature assembly and to substantially reduce the volume of packing material, thereby improving the performance of the valve over wider temperature ranges and pressure ratings.

Claims

1. A valve comprising:

a valve body having a valve cavity therein;

a valve element for controlling flow through the valve based on rotational position of the valve element about an axis; and

a single piece plastic polymer packing that surrounds said valve element and seals said valve element within said valve cavity;

said single piece packing being dimensioned to be installed on said valve element within a room temperature range.

2. The valve of claim 1 wherein said room temperature range is about 65-100°

F.

3. The valve of claim 1 wherein said packing has a generally cylindrical outer surface defined by a height H and an outer diameter D4, said packing having a ratio H/D4 of about 0.75 to about 0.85.

4. The valve of claim 3 wherein said ratio H/D4 is about 0.8.

5. The valve of claim 1 wherein said valve element comprises a ball and adjacent upper and lower trunnions;

said ball having an outer diameter D1 and at least one of said trunnions having an outer diameter D3;

wherein said valve element has a ratio D3/D1 of about 0.7 to about 0.9.

6. The valve of claim 5 wherein said ratio D3/D1 is about 0.8.

7. The valve of claim 1 wherein said packing has a generally cylindrical outer surface defined by a height H and an outer diameter D4, said packing having a ratio H/D4 of about 0.75 to about 0.85;

and wherein said valve element comprises a ball and adjacent upper and lower trunnions;

said ball having an outer diameter D1 and at least one of said trunnions having an outer diameter D3;

wherein said valve element has a ratio D3/D1 of about 0.7 to about 0.9.

8. The valve of claim 7 wherein said ratio H/D4 is about 0.8 and said ratio D3/D1 is about 0.8.

9. The valve of claim 1 wherein said polymer is selected from the group comprising polytetrafluoroethylene (PTFE), polyethylene, polyetheretherketone (PEEK) and fluorinated ethylene propylene.

10. The valve of claim 1 wherein said polymer comprises PTFE.

11. The valve of claim 1 wherein said valve element comprises a non-spherical flow control element.

12. The valve of claim 1 wherein said packing has an inner surface that forms an interference fit with said valve element when said packing is installed thereon prior to loading said packing within said valve body.

13. The valve element of claim 1 wherein said packing has an interference fit with said valve cavity when said packing is installed on said valve element and inserted into said valve cavity prior to loading said packing within said valve cavity.

32. The valve of claim 1 wherein said packing is live loaded.

14. A method for assembling a valve comprising the steps of:

forming a one piece plastic polymer packing adapted to seal a valve element within a valve cavity; and

installing said packing onto said valve element within a temperature range for which mechanical properties of the packing are substantially unchanged.

15. The method of claim 14 wherein said step of forming said packing comprises the step of machining said packing.

16. The method of claim 14 wherein said temperature range is selected so that the mechanical properties of the packing material are substantially unchanged as compared to the mechanical properties of the packing material at 70°

F.

17. A valve comprising:

a valve body having a valve cavity therein;

a valve element for controlling flow through the valve based on rotational position of the valve element about an axis; and

a packing that surrounds said valve element and seals said valve element within said valve cavity; and

said valve element comprising a ball and adjacent upper and lower trunnions;

said ball having an outer diameter D1 and at least one of said trunnions having an outer diameter D3;

wherein said valve element has a ratio D3/D1 of about 0.7 to about 0.9.

18. The valve of claim 17 wherein said packing has a generally cylindrical outer surface defined by a height H and an outer diameter D4, said packing having a ratio H/D4 of about 0.75 to about 0.85.

19. The valve of claim 17 wherein said packing comprises a polymer that is selected from the group consisting of:

PFA, filled PFA, polytetrafluoroethylene (PTFE), filled PTFE, polyethylene, polyetheretherketone (PEEK) and fluorinated ethylene propylene.

20. The valve of claim 17 wherein said packing is dimensioned to be installed on said valve element at a temperature below which said packing deforms.

21. The valve of claim 20 wherein said temperature is room temperature.

22. The valve of claim 17 wherein said packing is a single piece packing.

23. The valve of claim 17 wherein said packing is over molded onto said valve element.

24. A valve comprising:

a valve body having a valve cavity therein;

a valve element for controlling flow through the valve based on rotational position of the valve element about an axis; and

a packing that surrounds said valve element and seals said valve element within said valve cavity; and

said valve element comprising a ball and adjacent upper and lower trunnions;

wherein said packing has a generally cylindrical outer surface defined by a height H and an outer diameter D4, said packing having a ratio H/D4 of about 0.75 to about 0.85.

25. The valve of claim 24 wherein said ball has an outer diameter D1 and at least one of said trunnions has an outer diameter D3;

wherein said valve element has a ratio D3/D1 of about 0.7 to about 0.9.

26. The valve of claim 24 wherein said packing is a single piece packing.

27. The valve of claim 24 wherein said packing is a multi-piece packing.

28. The valve of claim 24 wherein said packing is installed onto said valve element at room temperature.

29. In combination, a valve element and a single piece plastic polymer packing therefore, wherein said packing is installed onto said valve element at room temperature.

30. The combination of claim 29 wherein said valve element comprises a ball and stem and with at least one trunnion adjacent said ball.

31. A valve comprising:

a valve body having a valve cavity therein;

a valve element for controlling flow through the valve based on rotational position of the valve element about an axis; and

a packing that surrounds said valve element and seals said valve element within said valve cavity;

said valve element comprising a ball and adjacent upper and lower trunnions;

said ball having an outer diameter D1 and at least one of said trunnions having an outer diameter D3;

wherein said valve element has a ratio D3/D1 that facilitates assembly of said packing onto said valve element at room temperature.

33. A valve comprising:

a valve body having a valve cavity therein;

a valve element for controlling flow through the valve based on rotational position of the valve element about an axis; and

a single piece plastic polymer packing that surrounds said valve element and seals said valve element within said valve cavity, wherein the single piece packing is completely contained in the valve body cavity;

said single piece packing being dimensioned to be installed on said valve element within a room temperature range.

34. A method for assembling a valve comprising the steps of:

forming a one piece plastic polymer packing adapted to seal a valve element within a valve cavity; and

installing said packing onto said valve element within a temperature range for which mechanical properties of the packing are substantially unchanged; and

installing the packing and valve element in the valve cavity such that the packing is completely contained in the valve cavity.