JP2019039520A - Eccentric rotary valve - Google Patents

Abstract

To prevent a jumping phenomenon by preventing abrasion deterioration of a seal in a triple or quadruple eccentric rotary valve.SOLUTION: The present invention relates to a quadruple eccentric butterfly valve V comprising: a cylindrical valve box 11 in which a fluid flows; a valve rod of which the axial center is separated from an axial center of the valve box; a valve body 13 which is provided eccentrically to the valve rod; an elliptically conical valve body valve seat 13a of which the axial center is tilted with respect to the axial center of the valve box; and an elliptically conical valve box valve seat 11a to/from which the elliptically conical valve body valve seat is connected/disconnected. Both the valve body valve seat and the valve box valve seat are formed from a metal and defined as a metal seal, and an elastic seat 15 in contact with the valve box valve seat is provided in the valve body valve seat. The elastic seat is mounted via a valve seat presser 14 while taking a fastening margin 17 by bolting 16. A side face (valve seat 14a) of the valve seat presser is abutted to the valve box valve seat, thereby constituting the metal seal. The elastic seat is extruded outsides (closer to the valve box valve seat) with fastening a bolt.SELECTED DRAWING: Figure 3

Description

  The present invention is an eccentricity used as a shutoff valve or a flow control valve provided in piping for fluid transportation of water and gas such as instrumentation equipment such as petroleum and chemical plants, power generation equipment, and industrial water and hydroelectric power generation equipment. It relates to a rotary valve.

  This type of eccentric rotary valve has a double eccentric structure, and as shown in FIGS. 4A to 4C, the double eccentric rotary valve includes a cylindrical valve box 1 in which a fluid w flows, and its A valve stem (valve shaft) 2 inserted into the valve box 1 and having an axis a separated from the central axis b (axis c) of the valve box 1 (valve body 3) (secondary eccentricity, FIG. 4A). (See (a), (b)), the valve body (plug) 3 provided eccentric to the valve stem 2 (shaft center a) (primary eccentricity, see FIG. 4A (b)), valve body valve seat The structure which has the valve-box valve seat 1a contacted / separated to (seat part) 3a is common (refer patent document 1, Claim 1, FIGS. 1-3). In the figure, reference numeral 2a denotes an arm for supporting the valve body 3 on the valve shaft 2.

  In many of these double eccentric rotary valves, as shown in FIG. 4A (b), the valve box valve seat 1a is formed of an elastic body such as metal having an elastic structure, or the valve body valve seat 3a is formed of a similar elastic structure. Or an elastic body with For this reason, under high fluid pressure, the valve seat 1a is bent by the high pressure and the sealing performance is deteriorated to cause leakage, so that it cannot be used for such a high pressure fluid.

That is, many of the valves having a double eccentric structure exhibit a closing performance at a valve body valve seat 1a having an elastic structure and a valve body position where the valve body valve seat 3a has an appropriate tightening allowance (position sheet). The closing performance is given by the elastic force of the valve box valve seat 1a of a metal piece having an elastic structure. This is because even if the high-pressure fluid w is to be closed, the fluid pressure (for example, 20 kg / cm ² or more) higher than the elastic force that closes the valve seats 1a and 3a is applied to the seat portion (the contact portion of both valve seats) 1a. This is because if the load is applied to 3a, the seat portions 1a and 3a are opened (gap is generated) and the valve closing performance cannot be ensured.
For this reason, in the double eccentric rotary valve, even if the valve closing direction torque given by the valve operation (shaft rotation or the like) is increased, the valve closing performance cannot be improved.

  Further, the eccentric rotary valve is in contact (contact) with both valve seats 1a and 3a from one of the center lines c of the valve box 1, so that the flow direction of the fluid w (the pressurization direction when fully closed). There is a superior side and a non-dominant side of leakage performance. For example, in FIG. 4A (b), the flow direction from the right side (the reverse direction of the arrow w) is the dominant side, and the flow direction from the left side (the direction of the arrow w) is the non-dominant side. This dominant side is called the positive pressure direction, and leakage is likely to stop. The non-dominant side is called the reverse pressure direction, and leakage is very difficult to stop. The positive pressure side is because the valve body 3 and the valve body valve seat 3a are pressed by the fluid pressure, and the close contact with the valve box valve seat 1a is enhanced. The reverse pressure side is that the fluid pressure is the valve body 3 and the valve body valve. This is because the seat 3a acts in a direction to escape from the valve box valve seat 1a.

Further, since the valve seat 1a or 3a having an elastic structure is in close contact with each other (seat portion) by an elastic force, the contact portion of the valve seat 1a is worn every time the opening / closing action is performed, and the wear deterioration is caused by the wear deterioration. Leakage performance and life when fully closed will be affected.
In addition, since the valve seats 1a and 3a are brought into close contact with each other by an elastic force, when used as a control valve, when the signal for performing the valve slight opening operation from the closed state is input, Even if the valve body 3 is finely moved, the valve seats 1a and 3a are not separated until the elastic force disappears (does not open), and when an additional signal for further valve opening operation is input, the valve body 3 is released from the elastic force. A phenomenon in which the valve body 3 opens suddenly (opens) is observed. This phenomenon is called a jumping phenomenon and is not preferable when performing highly accurate flow rate control.

As a valve that can suppress the jumping phenomenon to the limit, there is a triple eccentric rotary valve. In addition to the above-mentioned double eccentric rotary valve, this valve has a valve body valve seat shape (conical surface shape) shaft center (conical central axis d forming the valve seat 13a in FIG. The seal faces of the valve box valve seat 1a and the valve body valve seat 3a are elliptical sections (Patent Document 2, paragraphs 0019 to 0033, FIGS. 1 to 5). , Patent Document 3, paragraphs 0002, lines 11 to 21, FIGS. 1 and 5).
In addition, in this triple eccentric rotary valve, a quadruple eccentric rotary valve in which the conical shape forming the valve seat surface (seat surface) is an elliptical cone shape has been devised. The valve hole of this quadruple eccentric rotary valve is a perfect circle.

These triple eccentric rotary valves and quadruple eccentric rotary valves have extremely few or almost no contact points between the valve seats during the operation of the valve body (when opening and closing valves). (Metal sheet) can be adopted. When the metal sheet is used, the torque in the valve closing direction of the valve shaft can be increased to improve the valve closing performance (because of contact with the torque seal), so that it can be adapted to high temperature and high pressure.
Also, if the valve seat is a metal sheet, it can be tightened with a torque seal that can hold the fully closed position with the torque of the valve body, and by applying high torque to the valve stem, the leakage performance under high pressure fluid can be improved. It is possible to improve the leakage performance for both the positive pressure and the reverse pressure.

JP 7-317923 A JP 2006-161918 A JP 2002-130487 A

In this way, triple eccentric rotary valves and quadruple eccentric rotary valves can improve leakage performance in both positive and reverse pressures even under high-pressure fluid by using a torque seal. It is difficult to obtain a complete seal (complete leakage performance).
For this reason, in the triple and quadruple eccentric rotary valve, as shown in FIG. 5, the valve body valve seat 3 a is constituted by an elastic sheet, and the seat 3 a is valved by a screw (bolt) 5 via a valve seat retainer 4. There is something attached to 3.
Although the sealing with the elastic sheet 3a improves the leakage characteristics as an eccentric rotary valve, there is a problem that the jumping phenomenon cannot be completely prevented due to the elastic sheet 3a, and repair due to wear deterioration of the elastic sheet 3a. And valve seat replacement is required.

  Under the above circumstances, an object of the present invention is to completely prevent a jumping phenomenon in a triple or more eccentric rotary valve, and to bring it closer to a perfect seal with very little wear deterioration.

In order to achieve the above object, the present invention takes into account a seal by an elastic body in addition to a metal seal in a triple or more eccentric rotary valve.
Since it is a triple or more eccentric rotary valve, a metal seal can be adopted, so the above-mentioned jumping phenomenon, which is the feature of the valve, can be suppressed to the limit, and the valve closing direction torque of the valve shaft is increased to improve the valve closing performance. It can be improved. For this reason, it is possible to cope with high temperatures and high pressures, and it is possible to improve leakage performance in both positive and reverse pressures even under high pressure fluid. That is, the characteristics of the metal seal can be secured.
Furthermore, in addition to this metal seal, a seal with an elastic sheet is added, so that it is possible to approach a complete seal (complete leakage performance) that cannot be secured by the metal seal. At this time, since it is a triple or more eccentric rotary valve, the locations where the valve seats are in contact with each other are extremely few or hardly contacted, so that the wear of the elastic sheet is extremely small and the life can be extended.

  Specifically, a cylindrical valve box through which fluid flows, a valve stem inserted into the valve box, the shaft center of which is separated from the axis of the valve box, and a valve body provided eccentric to the valve stem An eccentric rotary valve having a valve body valve seat whose axis is inclined with respect to the shaft center of the valve box, and a valve box valve seat to which the valve body valve seat contacts and separates. Both of the valve seats are made of metal to form a metal seal, and one of the valve body valve seat and the valve box valve seat is provided with an elastic sheet in contact with the other.

  In this configuration, the elastic sheet is attached to the valve body by bolting via a seat (valve seat) retainer, and the valve seat retainer contacts the metal valve box valve seat to constitute the metal seal. Can be. At this time, if the valve seat retainer is configured to be attached to the valve body main body with a tightening margin (gap), the valve seat valve seat and the valve seat retainer valve seat come into contact with each other (a metal seal is formed). ), The contact pressure causes the valve seat retainer to be pushed toward the elastic seat and press the elastic seat, so that the elastic seat presses against the valve box valve seat and the sealing effect is increased.

  Since the present invention is configured as described above and a seal by an elastic sheet is added in addition to the metal seal, it can be brought close to a perfect seal.

Front view of an embodiment of an eccentric rotary valve according to the present invention Cutting plan view of FIG. 2 is an enlarged view of the main part of FIG. A conventional example is shown, (a) is a partially cutaway side view, (b) is a cut front view. The valve body of the conventional example is shown, (a) is a front view, (b) is a left side view, and (c) is a plan view. FIG. 4A (a) main part enlarged view Main section enlarged sectional view of the conventional example

An eccentric rotary valve according to the present invention is shown in FIGS. 1 to 3, and this embodiment is a quadruple eccentric butterfly valve V. FIG. Similarly to the conventional eccentric rotary valve, this quadruple eccentric butterfly valve V is also inserted into the cylindrical valve box 11 in which the fluid w flows and the valve box 11. A valve stem (valve shaft) 12 distant from the shaft center (valve body flow path center) c, a valve body (plug) 13 provided eccentric to the valve stem 12, and a valve body valve seat (seat portion) 13a And a valve box valve seat 11a that contacts and separates.
The center of the valve body (valve body) 13 is eccentric with respect to the valve shaft center a (single (secondary) eccentricity), and the valve shaft center a is eccentric with respect to the pipe central shaft c (double (next) The cone center axis d forming the valve seats 11a and 13a is eccentric with respect to the pipe (valve box) center axis c (triple (next) eccentricity), and the conical valve body valve seat The valve hole 18 formed by contact of both valve seats 11a and 13a becomes a perfect circle (becomes a perfect circle seal structure).

If the valve hole 18 is a perfect circle, when this quadruple eccentric butterfly valve V is used (installed) in a substantially true cylindrical pipe, the cross-sectional shape of the fluid w is a substantially perfect circle. It changes from a substantially perfect circle to a perfect circle, and no pressure loss or the like occurs, and a stable fluid flow can be ensured.
The “perfect circle” in the present invention does not mean only the same circle with the entire diameter, but also includes the case of a diameter change that does not affect the distribution.

In this quadruple eccentric butterfly valve V, the valve element valve seat 13a is formed by the valve seat retainer 14 and the peripheral end surfaces 14a and 15a of the elastic seat 15, which is a feature of the present invention.
The valve seat retainer 14 has a disk shape made of metal, and is attached to the valve body 13 by screwing a bolt 16 with an annular elastic sheet 15 interposed therebetween. The screwing amount is set so that a gap 17 is generated between the valve seat retainer 14 and the valve body 13. The gap 17 is appropriately set by an experiment or the like so that a sealing pressure by the elastic sheet 15 described later becomes a required value and the abrasion of the elastic sheet 15 does not become intense.
As shown in FIG. 1, the bolts 16 are appropriately provided around the valve seat retainer 14. The bolt interval is preferably equal.

In the quadruple eccentric butterfly valve V of this embodiment, the valve body 13 is rotated by rotating the valve shaft 12 (in the direction of the arrow in FIG. 2), and both valve seats 11a and 13a are in contact with each other. The valve is opened or closed with a metal seal.
At this time, since the valve seat retainer 14 is attached to the valve body main body with a tightening margin (gap 17), when the valve box valve seat 11a and the valve seat valve seat 14a of the valve seat retainer 14 abut (metal seal). The valve seat retainer 14 is pushed toward the elastic sheet 15 by the contact pressure, and presses the elastic sheet 15. For this reason, the elastic sheet 15 bulges out and comes into pressure contact with the valve box valve seat 11a to increase the sealing effect. That is, the valve body valve seat 15a of the elastic seat 15 and the valve box valve seat 11a are contacted with high contact pressure.

As described above, since the seal by the elastic sheet is added in addition to the metal seal, the jumping phenomenon, which is a characteristic of the metal seal, is suppressed to the limit, and the valve closing direction torque of the valve shaft 12 is increased to close the valve. The performance can be improved, and it is possible to cope with high temperature and high pressure, and even under high pressure fluid, the leakage performance can be improved in both the positive pressure and the reverse pressure in the direction of the double arrow shown in FIG.
In addition to this, since the seal by the elastic sheet 15 is added, it is possible to approach a complete seal (complete leakage performance) that cannot be secured by a metal seal. At this time, since it is a quadruple eccentric butterfly valve V, there is extremely little or no contact between the valve seats 11a, 13a (14a, 15a), and therefore the wear of the elastic sheet 15 is extremely small. It has a long life.

The above is the case of the quadruple eccentric rotary valve (butterfly valve) V, but the present invention can be adopted even with a triple eccentric rotary valve, and the effects of the present invention can be obtained. Moreover, the valve box valve seat 11a can also be comprised with an elastic sheet | seat and its pressing member.
Thus, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1, 11 Valve box 1a, 11a Valve box valve seat 2, 12 Valve rod 3, 13 Valve body (valve body)
3a, 13a Valve body valve seats 4, 14 Valve seat retainer 14a Valve body valve seat 15 composed of valve seat retainer 15 Elastic seat 15a Valve body valve seat 6, 6 composed of elastic seat Valve hole V Eccentric rotary valve (quad eccentric butterfly valve )
a Valve stem axis (center line)
b Vertical axis of valve box (center line)
c Valve box axis (pipe center)
d Center axis of valve seat 13a (conical surface)

Claims (3)

A cylindrical valve box (11) through which the fluid (w) flows and the valve box (11) are inserted into the valve box (11), and the axis (a) is separated from the axis (c) of the valve box (11). A valve stem (12), a valve body (13) provided eccentric to the valve stem (12), and a valve body whose shaft center (d) is inclined with respect to the shaft center (c) of the valve box (1) An eccentric rotary valve (V) having a valve seat (13a) and a valve box valve seat (11a) to which the valve body valve seat (13a) contacts and separates,
Both the valve body valve seat (13a) and the valve box valve seat (11a) are made of metal to form a metal seal, and one of the valve body valve seat (13a) and the valve box valve seat (11a) An eccentric rotary valve provided with an elastic sheet (15) in contact with the other.   The elastic sheet (15) is attached to the valve body (13) by a bolt (16) via a valve seat retainer (14), and the valve seat retainer (14) is made of a metal valve box valve seat (11a). The eccentric rotary valve according to claim 1, wherein the metal seal is configured in contact with the metal seal.   The eccentric rotary valve according to claim 2, wherein the valve seat retainer (14) is attached to the valve body main body (13) with a tightening margin (17).

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