JPS604393B2 - gate valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gate valve, and more particularly to a gate valve using a divisible gate.

Bidisc gates have been commonly used for gate valves due to their functional and manufacturing advantages.

Such a configuration can accommodate large manufacturing variations in gate discs and valve seats due to the large degree of freedom of movement of each gate disc, while at the same time being able to accommodate differences in heating and cooling rates and stresses caused by heating and cooling rate differences. Even if the valve seat is strained due to the valve seat, the sealing engagement between the two can be completed. SUMMARY OF THE INVENTION It is an object of the present invention to provide a gate valve using a bidisk gate that is improved in terms of manufacturing, performance and reliability. In the gate valve of the present invention, in a conventional gate valve having a gate consisting of two gate pieces, a corner-keeping member is reinserted between both gate pieces, and the space-keeping member is inserted between the gate piece and the valve seat. By replacing the sealing engagement surface with a thicker one as it wears out, the gate is always engaged in the proper position with respect to the valve seat, regardless of the progress of wear. .

In this case, the spacing member is made from a single piece independent of the gate piece, and its thickness is simply increased gradually as the gate piece and the valve seat wear out. Therefore, it does not take much time to replace the insulation member, and after the insulation member is inserted and the gate is erected, the gate operates stably in the same way as the subordinate one, so the present invention is extremely easy to maintain. A highly reliable gate valve can be obtained at low cost. According to a second aspect of the present invention, in the gate valve of the present invention as described above, a retaining device for the insulation portion, which protrudes from the opposing surfaces of both gate pieces, is further provided; A gate valve is obtained which is provided with a guide for the gate so that the pieces do not separate from each other during the opening and closing movement and the Hoto member does not become disengaged from the retaining device.

Next, preferred embodiments will be described with reference to the accompanying drawings.

FIG. 1 shows a gate valve 10 constructed in accordance with the present invention for high pressure fluid in a power generating device.

Such gate valves have diameters ranging from 3.81 cm (11 no. 2 inches) to 106.68 cm (42 inches) and pressure resistances of 104 kg/unit and 15
7k9 no, 261k9/ground, 435k9/ground and 78
It is in the 3kg/class. The gate valve consists of a valve body 12, a bonnet assembly 14, a yoke assembly 20, and a handle assembly 22.

As described below, when the handle theory assembly 22 is rotated, a pair of flow passages extend through the valve body 12 along the flow passage axis 28 between the outer end outlets 30, 32. 3
The valve stem assembly 24 and the bi-disc gate 26 are moved up and down to open and close the lotus passage between the valve stems 6 and 38. The valve 10 allows fluid to flow in both directions, with the direction of fluid flow depending on which flow path the power generating device is connected to. The valve body 12 has parts 33, 34 forming flow passages 36, 38 adapted to a central valve action control chamber housing the gate 26, and a part 35 accommodating means for controlling the opening and closing of the passages between the flow passages. are doing.

Further, the valve body 12 has a generally T-shape and is made by casting carbon steel. Flow passages 36, 38 are aligned with flow passage axis 2
8 in coaxial alignment. Valve body 1
The ends of the two portions 35 define a cylindrical central control chamber entrance 40 that is open upwardly along an axis 42 perpendicular to the flow passage axis 28 . flow passage 36,
A counterbore 50, 52 is formed at the inner end of each of the valves 38 in which a cylindrical valve seat 54, 55 is seated.

The valve seating 54 is provided with a hardened annular seat 56 (FIG. 4), which together constitute a valve seat. The annular seat 56 is aligned with the axis 4
It is arranged in a plane inclined by 50 relative to 2. These planes are arranged symmetrically with the marquee line 42 in between. The valve seat IJ ring 54 is fixed to the inner surface of the valve body 12 by a continuous circumferential weld 58. Bonnet assembly 1
4 is held above the closure 40 of the central valving control chamber by a stopper 60.

The snap ring 60 is held within a circumferential groove 65 formed on the inner circumferential surface of the entrance portion 40 . Bonnet assembly 1
The bonnet 64 of No. 4 is pulled up by the bolt 62 through the outer flange 63 and is tightened by the stopper 60'. The bonnet 64 has a central hole for receiving the valve stem 70 of the valve stem assembly 24. A handle wheel assembly 22 is attached to the outer end of the valve stem 70, and a gate 26 is attached to the inner end of the valve stem 70. The packing retainer assembly 76 is attached to the valve stem 70
The surrounding area is sealed. The yoke assembly 20 is retained at the end of the portion 35 of the valve body 12 by a split yoke stop ring 78. A pair of roller bearings 80, 82 are mounted to yoke assembly 20 axially spaced apart.

Each roller bearing 80, 82 has an outer race supported by a counterbore of the yoke assembly 20 and a rotatable push 84 having a female threaded portion formed on the inner circumferential surface thereof to engage with a threaded portion 86 of the valve stem 70. and an inner race fixedly supported on the outer peripheral surface of the inner race. The hook 84 is the handle assembly 22
The handle assembly 22 rotates as the handle assembly 22 rotates. Rotation of the handle assembly 22 raises and lowers the valve core 70 through the gland assembly 76, thus moving the gate 26 between the lowered closed position shown and the raised open position. up and down. To reduce the vertical height of the valve, the gate 26 is adapted to be housed within a generally semi-recessed recess 90 formed in the underside of the bonnet 64. The gate 26 has two gate disks 100, 102 of the same shape.

Both gate discs 100, 102, when assembled, have seat contact surfaces as described below. These valve seat contact surfaces sealingly engage the annular seat 56 of the valve seating 54 to prevent fluid from exiting past the sealing engagement surfaces. Each gate disc has a hardened protruding valve seat contact surface 1
04, and the same surface 104 is at an angle equal to the inclination of the annular seat 56 with respect to the opposite flat back surface 110'.
In other words, it is a flat surface that has been ground to a 5o angle. The contour of the valve seat contact surface 104 is slightly larger than that of the annular seat 56. During manufacture, the gate is axially dimensioned so that the gate axis 106 in the closed, fully seated position is above the flow passage axis 28. This ensures that even if the valve seat surface wears out with use, the valve seat contact surface 104 has a larger outer diameter than the annular seat 56.
A full sealing engagement will be maintained as the gate axis 106 is lowered until the top of the 04 no longer engages the annular seat 56. As is clear from FIG. 8, the gate disk 10
The back surface 110 of 2 is substantially flat except for just three sector-shaped protrusions 112 equally spaced in the same circumferential direction with respect to the axis 106 . This arrangement provides a consistent reference surface for accurate machining of the seat contact surfaces 104 of the individual gate discs and for other machine operations. Upon assembly, these protrusions 112 interlock with corresponding sector protrusions on a mating gate disc to form a divisible annular hub. (Figure 2). Each side of each protrusion is formed with circumferential clearance relative to adjacent protrusions to allow limited relative movement between the gate discs. The annular hub is a protruding holding device that holds an annular spacing ring 120 that is a spacing member. The spacing ring 120 is coupled to the individual gate discs to secure the gate 2.
6 is of sufficient thickness to ensure a sealing engagement with the valve seat, and its opposite sides are parallel to each other. The spacing ring 120 has a diameter 4 mm smaller than that of the seat contacting surface so that the valve seat contacting surface 104 is easier to manipulate when subjected to pressure and stem loads. Further, as shown in FIG. 4, a part of the inner wall of the flow passage within the valve body 12 protrudes to form gate guides 103, 103, and gate discs 100, 1
It surrounds the protrusions 105, 105 of the gate 26 and guides the vertical opening and closing movement of the gate 26, and during the movement, the gate discs 100, 10
2 are separated from each other and the spacing ring 120 is prevented from coming off.

If the valve seat contact surfaces 104 become excessively worn, or if any valve seat contact surfaces 104 are abraded or otherwise damaged during operation, the gate must be removed. Also, the valve seat contact surface 104 must be repositioned.

This results in the metal surface being scraped away, causing the gate to be moved too far down past the point where a sealing contact is achieved. If this situation occurs with a conventional gate valve, the entire gate will need to be replaced. However, in the configuration of the present invention, it is only necessary to replace the spacing member (the spacing ring in this embodiment). Replacement of this spacing ring occurs when the sealing engagement between the seat contact surface 104 and the annular seat 56 is disrupted due to a reduction in the dimensions of the gate disk due to refinishing of the seat contact surface 104. It is also done.

That is, by replacing the spacing ring with a thicker wall, the reduction in size of the gate disk is compensated for and a sealing engagement is again achieved. As shown in FIGS. 6 and 7, the lower end of the valve stem 70 has a T-shaped structure having a collar 130, a cylindrical neck 132, and a T-shaped wedge 134. As shown in FIGS.

Collar portion 130 has a substantially frustoconical surface provided with an annular bearing undersurface 136 . T-shaped wedge part 13
4 is a curved surface 137 having approximately the same diameter as the outer diameter of the collar portion 130;
and an inclined side surface 1 arranged symmetrically with respect to the axis 42 so as to form a downwardly tapered wedge-shaped portion.
38. As shown in FIGS. 6 and 8, the individual gate discs 100, 102 are connected to the valve stem 70.
an upper bearing surface 140 engageable with a lower annular bearing surface 136 of the
A semi-circular axial groove 144 loosely surrounding neck 132 of valve stem 70 and both axes 106 and 4
2, and a wedge-shaped transverse slot 146 extending perpendicularly to 2.

This slot 146 lies within the boundaries of the gate seat area and therefore has a lowered profile. Raised slope pad 1
48 pairs are formed on the sides of the slot 146 with a slight clearance to the sloped side 138 of the wedge 134. As shown in FIG. 6, the end of the valve stem is received within the slot 146 and the wedge portion 134
46 boundaries. This slot 146 "reliably holds the end of the valve stem 70 and prevents it from falling into the flow path if the valve stem ruptures. Because the gate 26 is wedge-shaped, The force transmitted by the mandrel assembly 24 to the valve seat surface will be significantly multiplied to provide a greater sealing force between the sealingly engaging surfaces.

The splittable wedge-shaped design allows the valve seat contact surfaces to be steered independently, so that each individual valve seat contact surface can simulate under fluid pressure and engage the opposing valve seat surface. This can be done without any reaction from the other gate disc. This substantially equalizes the seat contact forces on the individual seat contact surfaces. Therefore, when it is desired to move the gate to the opposite position, the T-shaped wedge 13
The upper surface of slot 146 engages with the lower surface of slot 146, and the force exerted by the engagement is such that the engagement of both valve seat contact surfaces can be released since both gate discs are independent of each other. Sufficiently reduce the valve seat contact force. As the gate 26 is advanced upwardly by rotation of the handle assembly 22 or elevation of the valve stem assembly 24 until the collar 130 of the valve stem 70 engages the backseat 150 of the bonnet 64, the flow passageway is closed. Flow through 36, 38 is substantially unrestricted.

It should be noted that the protruding valve seat contact surface 104 contacts the valve seat with mechanical sliding movement or sliding movement due to pressure loads when lowering the gate to the closed position and raising the gate towards the open position. time and therefore wear on these surfaces is reduced.

[Brief explanation of drawings]

1 is a cross-sectional view of a gate valve constructed in accordance with the present invention in the closed position; FIG. 2 is a cut-away cross-sectional view taken along line 2-2 of FIG. 1; and FIG. 3 is a gate disc valve. 4 is a cross-sectional view taken along line 4--4 of FIG. 1; FIG.
6 is an enlarged cross-sectional perspective view showing the engagement of the gate disc with the end of the valve stem; FIG. 7 is an enlarged cross-sectional view of the end of the valve stem. FIG. 8 is an enlarged, partially cutaway perspective view of the gate disk. 10... "gate valve", 12... "valve body C24...
"Valve stem assembly", 26..."Gate consisting of two pieces 3
0, 32... "Outer end outlet", 36, 38... "Pair of flow passages", 42... "Axis", 54... "Valve seat" 56... "Annular seat", 100, 102...'Gate disc', 104...''Valve seat contact surface C' 110...
"Back side of gate disk", 112... "Fan-shaped projection", 1
20... ``Separate Ring Ha'' 146... ``The slot is a grandchild.

Claims (1)

[Scope of Claims] 1 each having an inner end communicating with a central valving control chamber opening upward along an axis and an outer end connectable to a fluid flow conduit; a valve body having a pair of flow passages, disposed in two planes that sandwich the axis and asymptotically approach the central axis as you move away from the opening of the central valve control chamber; a valve seat adjacently surrounding the inner end of the flow passageway, and a two-piece gate that is translated by a valve stem assembly between open and closed positions of the valve along the axis; each piece is angled with respect to the axis parallel to the engagement surface of the opposing valve seat for sealing engagement with the opposing valve seat in the closed position at a predetermined axial position. a valve seat contacting surface and a locating surface opposite the valve seat contacting surface perpendicular to the fluid flow conduit, and each half of the gate has a valve stem assembly with the valve stem assembly between the open and closed positions. In a gate valve provided with means for movably engaging said assembly, said gate halves have sufficient space between said valve seat contact surface and said valve seat engagement surface in said closed position. a replaceable, independent, single-piece spacing member is provided for separating opposite sides of the gate in sealing engagement with each other, the spacing member having a locating surface on both halves of the gate; A gate valve characterized in that the contacting surfaces are parallel to each other. 2. having a pair of flow passages each having an inner end communicating with a central valving control chamber opening upwardly along the axis and an outer end connectable to a fluid flow conduit; a valve body, and a valve body disposed in two planes that sandwich the axis and asymptotically approach the axis as you move away from the opening of the central valve control chamber, and adjacent to the central valve control chamber, the flow passage includes a valve body; a valve seat surrounding an inner end, and a two-piece gate that is translated by a valve stem assembly between open and closed positions of the valve along the axis, each piece of the gate being predetermined. a valve seat contacting surface that is inclined with respect to the axis so as to be parallel to an engagement surface of the opposing valve seat for sealing engagement with the opposing valve seat in a closed position and at a closed axial position; a locating surface perpendicular to the fluid flow conduit opposite the valve seat contacting surface, and a locating surface perpendicular to the fluid flow conduit on opposite sides of the valve seat contacting surface; In a gate valve provided with a device for engaging with a solid body, there is a space between the two halves of the gate such that the valve seat contact surface and the valve seat engagement surface are sufficiently sealed in engagement in the closed position. A replaceable, independent, single-piece spacing member is provided for separating the two halves of the gate from each other, the surfaces of the spacing member in contact with both locating surfaces of the gate being parallel to each other. A protruding holding device is provided that protrudes from the positioning surfaces of both pieces of the gate and holds the spacing member between the two pieces,
A guide device is provided for preventing separation of the two halves of the gate and disengagement of the spacing member from the protruding retaining device when the gate moves between the open and closed positions, the guide device being configured to prevent the fluid from separating. A gate valve having a protrusion projecting from the flow conduit into the central valving control chamber, wherein both halves of the gate are received within the guide device in the closed position of the gate.