JP2003525411A - Fire resistant ring seal system for plug valve - Google Patents

Abstract

A seal system having a non-flat cross-section and an annular pocket formed between two engagement surfaces of a pressure vessel, such as a refractory compressible ring and a plug valve. I have. The annular pocket is formed by providing a chamfer in one plane and closing the other. The ring is substantially filled when compressed in the annular pocket and the two faces meet.

Description

Detailed Description of the Invention

The present invention relates to plug valves, and more particularly to refractory closure seal ring systems that replace conventional gaskets with smaller bolts, smaller bonnets and more effectiveness. And reliability.

The existing state of fire resistance for plug valves is embodied by a graphite gasket and packing ring. Traditionally, asbestos and graphite materials have been used, but they are sufficiently compliant with compressive loads and provide a sufficiently robust seal to support pressure and mechanical loads. Also, those materials are sufficiently resistant to temperatures above 1400 degrees Fahrenheit. It is also resistant to many chemicals.

Conventional plug valve gaskets tend to be flat and wide. For example, in a typical conventional example, the thickness of the circular gasket is. 030 inches, width is 3/8 ~
It is 3/4 inch. The gasket extends outwardly from the valve body hole ID to the center of the body closing bolt, which required the body to have a flat, polished circular area for mounting. The body closure bolt had to keep the pressure vessel in a state invariant despite the fluid pressure load. The gasket seals a considerable load when the operating part pushes. It would be a great advantage if conventional graphite gaskets were more effective and could be replaced with seals that would have less bolt loading.

[0004]

[Summary of Invention]

The fire resistant seal of the present invention replaces the conventional gasket with a small fire resistant ring seal. The seal of the present invention differs from the conventional gasket in two principle points. First, the shape of the seal is different. Unlike conventional gaskets, the seal of this invention is not flat. Desirably circular, square, triangular, trapezoidal or other non-planar cross section to reduce bolt loading.

Secondly, a seal is arranged in the outward chamfer of the body flange, which flange closes against the adjacent closing flange. The seal is compliant because it is thicker. This obedience is combined with the chamfer structure to improve the sealing effect without the same bolt load. The smaller bolt load allows smaller parts to be used. The body flange is smaller and the inner flange is thinner. This results in a lighter and less expensive valve structure. In addition, the bolt becomes smaller, which leads to a reduction in weight and cost.

[0006]

[Object of the Invention]

A basic object of the present invention is to provide a lightweight, low cost refractory ring seal system for plug valves.

Another object of the present invention is to provide a plug valve with a non-flat ring seal and a chamfered seal pocket to reduce bolt loading.

A further object of the invention is to reduce the body flange, closure flange and bolt dimensions and the weight of the plug-type valve, thereby providing a more effective fire resistant seal and reducing the seal of the valve. Place it in an effective position.

A further object of the present invention is to provide a refractory ring seal system for a container containing a pressurized fluid.

[0010]

【Example】

In FIGS. 1 and 2, the plug valve 10 has a body 12 containing a rotary plug 14 with a flow path 16. The flow path 16 is associated with a connecting pipe (not shown) fixed to the valve 10 via a flange 18. The rotating plug 14 has a pair of slips 15. The slips are fixed on both sides of the plug and stop the fluid when the plug is rotated 90 degrees to position the flow path 16 in the direction orthogonal to that shown. The plug is integrated with the upper and lower trunnions 20, 26. The upper trunnion 20 is controlled by the operating portion 22 and the handle 24 to open and close the rotary plug 14.

When the slip seals the inlet / outlet port, the fluid in the valve body seeps out,
This type of valve is called a double block bleed valve. However, the ring seal system disclosed herein is not limited to the use of such valves, but may be used with other valves, pumps, etc., that require a refractory seal of the fluid under pressure. The bottom cover 28 is fixed to the lower end of the main body 12 with bolts 29. The upper end of the main body 12 is closed by a bonnet 30 fixed by a bolt ring 32 and a bolt 34.

The flange 36 of the bonnet 30 is in contact with the upper surface 38 of the body 12. As shown in FIG. 2, the upper surface 38 has a chamfer 40, which forms an annular pocket 42 for receiving a refractory ring seal 44. Below the chamfer 40 is an O-ring 4.
6 is attached to the main part of the bonnet 30. As shown in FIGS. 3 to 6, the refractory ring seal 44 is circular and has a trapezoidal cross section, and one end of the circular seal in the axial direction is thicker than the other end. The thicker axial end is located at the upper end of the chamfer 40 and is in direct pressure contact with the flange 36 of the bonnet 30 as shown in FIG.

The ring seal 44 is preferably manufactured by Union Carbide of New York. Because of the unique chamfer construction that locates the ring seal 44, the seal is more compliant and subject to longitudinal and lateral compression to provide a fire resistant seal. The shape and size of the ring seal 44 relative to the shape and size of the annular pocket 42 allows for a low bolt load seal from the bolt 34. The axial length of the ring seal 44 (A + B in FIG. 6) is preferably larger than the depth of the chamfered portion 40 along the axial direction of the rotary plug 14 by the length B (FIG. 6), and the thickness of the ring seal 44 is C is preferably the same as the width of the chamfer 40 along the radial direction of the rotary plug 14.

Due to the relative dimensions of these ring seals 44 and annular pocket 42, the ring seals will reliably fill the chamfer prior to connecting the bonnet 30 to the body 12.
In addition, the bolt 34 seal provides an excellent seal, and the load level is much lower than prior art gasket seals. This allows the use of small bolts. In addition, the low bolt load requirements reduce the size of the body upper surface 38 and bonnet flange 36. This results in a plug valve that is lighter, cheaper and meets safety standards.

[0015]   The present invention is not limited to the embodiments disclosed above.

[Brief description of drawings]

[Figure 1]   It is sectional drawing of the plug valve of this invention.

[Fig. 2]   It is an enlarged view of the part shown as "SEE FIG. 2" in FIG.

[Figure 3]   It is a perspective view of a ring seal used for this invention.

[Figure 4]   It is an enlarged view of the ring seal of FIG.

[Figure 5]   It is a side view of a ring seal.

[Figure 6]   It is an enlarged view of the part shown as "SEE FIG.6" in FIG.

[Explanation of symbols]

  10: Plug valve   12: Body   14: Rotating plug   16: Channel   40: Chamfer   42: Annular pocket

─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Knight, Colin, Gee.             United States Texas 77469 Li             Timmond Thompson Crossing             1811 (72) Inventor Conley, Jeffrey, Earl.             United States Texas 77450 Kay             Tee Westcliff Falls             21615 (72) Inventor Kupala, Jean, Tee.             United States Texas 77084 Hu             Stone Knotty Green 18222 F-term (reference) 3H053 AA24 BC14 DA03

Claims (10)

[Claims] 1. A body (12) including a rotating plug (14), the plug having a flow path (16) for selective association with a connecting port pipe, the body comprising: Surrounded by a bonnet (30) and a bottom cover (28) to form a sealed chamber in the body, the bonnet having a flange (36) that engages an upper surface (38) of the body and There is a fire resistant seal between the two, the seal having a non-flat compressible fire resistant ring, the ring having a chamfered portion (40) on the upper surface of the body
An annular pocket (42) located inside and shaped with a chamfer to receive the ring
A plug valve (10) characterized by having: 2. The valve according to claim 1, wherein the ring has a trapezoidal cross section. 3. A valve according to claim 1 or 2, wherein the ring has an uncompressed length exceeding the depth of the annular pocket. 4. The valve according to claim 1, wherein the ring has a dimension and a cross section that press-fit the annular pocket when the bonnet is attached to the main body. . 5. The ring according to claim 1, wherein the ring has a size and a shape for applying a sealing force in two orthogonal directions when the bonnet is attached to the main body. The valve described in one. 6. A sealing device for a closed container containing pressurized fluid, said container having at least two mating surfaces, said mating surfaces at least partially overlapping at a connection. Defining an annular pocket (42) formed by a chamfer (40) in the mating surface thereof, and further comprising a refractory compressible ring having a non-planar cross section, the ring comprising an annular pocket. A refractory seal device located within (42), wherein the other mating surface is configured to press the ring into the annular pocket. 7. The device of claim 6, wherein the ring has a trapezoidal cross section. 8. A device as claimed in claim 6 or 7, characterized in that the ring has an uncompressed length which exceeds the depth of the annular pocket. 9. A device according to claim 6, wherein the ring has a dimension and a cross section that press-fit the annular pocket when the bonnet is attached to the body. . 10. The ring according to claim 6, wherein the ring has a size and a shape for applying a sealing force in two orthogonal directions when the bonnet is attached to the main body. The device described in one.