Plug valve

• US 6,874,759 B2
• Filed: 11/13/2002
• Issued: 04/05/2005
• Est. Priority Date: 11/13/2002
• Status: Active Grant

• Current Assignee: SMC Kabushiki Kaisha
• Original Assignee: SMC Kabushiki Kaisha
• Inventors: Tozaki, Takashi, Aoshima, Hiroaki
• Primary Examiner(s): JACYNA, J CASIMER
• Application Number:
  US10/292,473
• Publication Number:
  US 20040089834A1
• Time in Patent Office: 874 Days
• Field of Search: 251309-312, 251/900, 251/904
• US Class Current: 251/309
• CPC Class Codes: F16K 5/04 with plugs having cylindrical surfaces; Packings therefor
• CPC Class Codes: Y10S 251/90 Valves with o-rings
• CPC Class Codes: Y10S 251/904 Snap fit plug valves

Abstract

A main valve body has a first passage, a second passage, and an opening which intersects the first passage and the second passage. A main plug body is rotatably inserted into the opening, and has an upper section into which a handle is inserted, and a lower section having a through-hole. An O-ring is seated on an annular groove which is provided in the vicinity of the through-hole. A seal-retaining member for preventing the O-ring from projecting is fitted to an expanded diameter section of the first passage. One end of the seal-retaining member tightly contacts an end surface of the expanded diameter section. A curved surface corresponding to an inner circumferential surface of the opening is formed at the other end of the seal-retaining member.

Claims

1. A plug valve comprising:

a main valve body having a first passage, a second passage, and a first opening intersecting said first passage and said second passage, said first opening having a cylindrical surface;

a plug member provided with a communication hole for communicating with said first passage and said second passage, said plug member being rotatable between a communication position for connecting said communication hole to said first passage and said second passage and an interruption position for interrupting communication between said first passage and said second passage;

a seal member provided on said plug member for surrounding an opening end of said communication hole; and

a seal-retaining member provided in said first passage and having a second opening, wherein slits or holes communicating with said first opening are provided in said seal-retaining member, said seal-retaining member having a cylindrically curved surface corresponding to said cylindrical surface of said first opening and conforming to an outer circumferential surface of said plug member,

wherein said seal member is prevented from projecting by said seal-retaining member when said plug member rotates and said seal member crosses said first passage.

2. The plug valve according to claim 1, wherein said seal-retaining member is disposed so that said slits or holes are arranged in a direction substantially perpendicular to an axial direction of said plug member.

3. The plug valve according to claim 1, wherein said seal-retaining member is arranged together with a buffer member.

4. The plug valve according to claim 1, wherein said seal-retaining member is arranged together with a spacer.

5. The plug valve according to claim 1, wherein said seal-retaining member comprises a spacer and a buffer member provided between said spacer and said seal-retaining member.

6. A plug valve comprising:

a main valve body having a first passage, a second passage, and a first opening intersecting said first passage and said second passage;

a plug member provided with a communication hole for communicating with said first passage and said second passage, said plug member being rotatable between a communication position for connecting said communication hole to said first passage and said second passage and an interruption position for interrupting communication between said first passage and said second passage;

a seal member provided on said plug member for surrounding an opening end of said communication hole; and

a seal-retaining member provided in said first passage and having a second opening, at least a part of said seal-retaining member conforming to an outer circumferential surface of said plug member,

wherein said seal-retaining member is arranged together with a buffer member, and

wherein said seal member is prevented from projecting by said seal-retaining member when said plug member rotates and said seal member crosses said first passage.

7. The plug valve according to claim 6, wherein slits or holes for communicating with said first opening are provided in said seal-retaining member.

8. The plug valve according to claim 7, wherein said slits or said holes are provided in a curved surface of said seal-retaining member conforming to said outer circumferential surface of said plug member.

9. The plug valve according to claim 7, wherein said seal-retaining member is disposed so that said slits or holes are arranged in a direction substantially perpendicular to an axial direction of said plug member.

10. A plug valve comprising:

a main valve body having a first passage, a second passage, and a first opening intersecting said first passage and said second passage;

a plug member provided with a communication hole for communicating with said first passage and said second passage, said plug member being rotatable between a communication position for connecting said communication hole to said first passage and said second passage and an interruption position for interrupting communication between said first passage and said second passage,

a seal member provided on said plug member for surrounding an opening end of said communication hole; and

a seal-retaining member provided in said first passage and having a second opening, at least a part of said seal-retaining member conforming to an outer circumferential surface of said plug member,

wherein said seal-retaining member comprises a spacer and a buffer member provided between said spacer and said seal-retaining member, and

wherein said seal member is prevented from projecting by said seal-retaining member when said plug member rotates and said seal member crosses said first passage.

11. The plug valve according to claim 10, wherein slits or holes for communicating with said first opening are provided in said seal-retaining member.

12. The plug valve according to claim 11, wherein said slits or said holes are provided in a curved surface of said seal-retaining member conforming to said outer circumferential surface of said plug member.

13. The plug valve according to claim 11, wherein said seal-retaining member is disposed so that said slits or holes are arranged in a direction substantially perpendicular to an axial direction of said plug member.