JPS6364671B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve, particularly a gate valve suitable for use in a high pressure and low temperature range. The gate valve of the present invention has a single valve seat and a circular valve element, and when the valve support or the gate sealing part moves downward, the valve is moved to the valve seat by the engagement action of two sets of cam surfaces. Watertight engagement.

Gate valves are regularly used in a wide range of fields. In particular, they are mainly used in the petroleum industry as control valves for gas and oil pipelines. Additionally, single circular valves and valve seats are used in various valve applications, particularly for hydrants. In this case, the valve seat moves vertically along the threaded shaft and engages the cam, compressing the circular valve onto the valve seat. In this type of valve, the cam is a single device disposed within the fluid passageway that necessarily obstructs and disrupts fluid flow. Moreover, in conventional valve systems having universal joint means for attaching the valve element, the circular valve, to a carriage or valve support, there is no valve system in which the fluid flow is straight and of the simple flow type. Therefore, in conventional valve systems, the obstruction of the circular valve causes a disturbance of the fluid, and the fluid changes its flow in each direction and is disturbed.

It is an object of the present invention to have a single circular valve and valve seat with a straight flow path and limited free movement relative to the valve body, and to reduce fluid disturbance within the valve in the open state. Therefore, it is an object of the present invention to provide a gate valve having a valve mechanism in which the water sealing mechanism can completely escape from the valve body flow path.

The gate valve 10 of the present invention will be described with reference to the drawings, particularly FIG. 1. The gate valve 10 mainly includes a valve body 12, a lid portion 14, a valve stem 16, and a valve element or disc valve 1.
8, consisting of a valve support body 20.

As shown in FIG. 1, the valve body 12 has a first internal cylindrical portion 24 having a common axis and defining an internal flow passageway. An annular valve seat 22 surrounds the passageway 24, the plane of the annular valve seat 22 being generally perpendicular to the common axis, but slightly inclined (approximately 0-10 degrees). In this example, it is tilted by 5 degrees. At the end of the internal cylindrical section 24 there is a first flange 26 which becomes the inlet section 28 of the gate valve 10, and similarly at the other end of the internal cylindrical surface 24 there is a first flange 26 which serves as the inlet section 28 of the gate valve 10.
There is a second flange 30 that serves as an outflow portion 32 of zero.

The main part of the valve body 12 has a second cylindrical part 13,
At its end there is a third flange 34. The lid portion 14 is fastened to the third flange 34 with bolts,
Otherwise, it is fixed to other related members. Therefore, a valve storage chamber 15 is formed which accommodates the valve support 20 and the circular valve 18 when the valve is opened. That is, the valve storage chamber 15 is formed by the lid part 14 and the second cylindrical part 13.
The second cylindrical portion 13 of the gate valve body has an annular groove 38 and is fitted with an annular gasket 42 to prevent fluid from flowing out from the joint between the third flange 34 and the lid flange 36.

The lid flange 36 is fitted into the annular groove 3 to crimply hold the annular gasket 42 in place when the lid 14 is attached to the second cylindrical portion 13 of the valve body 12.
8 and has an annular protrusion 40 that engages with the groove.

As shown in the figure, the gate valve 10 includes a valve stem 16 extending vertically from the valve stem hole 44 of the lid 14 to the top 58 of the lid, and a handle chamber 64 for moving the valve support 20 up and down with respect to the annular valve seat 22. There is. At the bottom of the valve stem 16 is a T-shaped connection that supports the valve support 20. As shown in FIG. 4, the T-shaped connecting portion 4 of the valve stem 16
6 is the cross member 48 and the engaging portion 78 of the valve support body 20
has a central member 50 for engaging the cross member 48. The lid portion 14 is the second cylindrical portion 13 of the valve body 12
In order to crimply hold the annular gasket 42 in place when attached to the cap, the lid flange 36 has an annular projection 40 that is approximately the same size as and engages the annular groove 38.

As shown in the figure, the gate valve 10 includes a valve stem 16 extending vertically from the valve stem hole 44 of the lid 14 to the top 58 of the lid, and a handle chamber 64 for moving the valve support 20 up and down with respect to the annular valve seat 22. There is. At the bottom of the valve stem 16 is a T-shaped connection that supports the valve support 20. As shown in FIG. 4, the T-shaped connecting portion 4 of the valve stem 16
6 is the cross member 48 and the engaging portion 78 of the valve support body 20
has a central member 50 for engaging the cross member 48. These members thus limit the movement of the valve support relative to the valve stem in a direction perpendicular to the axis of the valve stem and keep the valve support 20 from moving the circular valve 18 into the annular valve seat 2.
It serves as a bearing for moving up and down relative to 2. Further, the valve stem 16 is provided with an annular water sealing portion 52 that slides into contact with a valve stem seat 54 located above the valve stem hole 44 when the valve stem reaches the uppermost position.

There are a plurality of annular valve stem sealing packing members 56 on the upper part 58 of the lid, which provide a water seal between the valve stem 16 and the lid 14 to prevent fluid from flowing out. These packing members 56 are in the form of washers and are compressed under pressure to form a seal around the valve stem 16.

The packing presser foot 72 is fixed by the handle chamber flange 62 so as to apply pressure to the packing member 56. Furthermore, this handle chamber flange 62
are secured to the top flange 60 of the lid by suitable bolts and nuts 74, 76 or other suitable means capable of adjustable compression compression of the packing material.

The handle 66 is in a vertically stationary position with respect to the handle chamber 64, and when the handle 66 is rotated, the internal threaded portion 68 of the handle engages with the valve stem 16.
The valve body 12 of the gate valve engages with the threaded portion 70 of the gate valve.
The valve stem moves up and down with respect to the lid portion 14.

The gate valve 10 of the present invention includes a machined disk-shaped front water sealing surface 9 that seals the annular valve seat 22 watertightly.
There is a valve element with 8 or circular valve 18.

The circular valve 18 has a threaded shaft 100;
This shaft axis is perpendicular to the plane 98 of the circular valve and coincides with an axis passing through the geometric center of the circular valve. A circular valve threaded shaft 100 is disposed within the central hole 82 of the valve support 20 and is held loose by a standard hexagonal nut 102 secured to the threaded shaft 100. The circular valve 18 is adapted for limited free movement of the valve within the valve support so that the valve automatically and uniformly closes when the circular valve and valve support are lowered into the water seal. Seat 22 is watertightly sealed.

As shown in FIG. 1, the valve support 20 includes a circular valve 1
It has two vertically erect arcuate members 84 disposed on one side of the central bore 82 for projecting the circular valve outwardly and for limited movement of the circular valve relative to the valve support. Figure 3).

Size of center hole 82 of valve support and nut 102
The degree of loosening of the valve shaft 100 determined by the position can be adjusted with a screw while leaving sufficient play between the nut 102 and the surface of the valve support. The combination of this play and the arcuate member 84 allows the circular valve 1
8 is automatically seated on the valve seat. At this time, the circular valve 18 is pivotally supported at a position inclined from the horizontal axis by about 5 degrees with respect to the central axis so as to uniformly seal the valve seat.

As shown in FIG. 4, the valve support 20 has an engaging portion 7.
8 has a pair of inwardly projecting edges 80 that retain the cross member 48 of the T-shaped portion 46 of the valve stem. Regarding the connection between the T-shaped part 46 and the valve support 20, the circular valve 1
There must be sufficient play so that 8 seats naturally around the annular valve seat 22 and has a suitable degree of free movement.

The valve support 20 has a pair of vertical guide pieces 86 (FIG. 2) formed by a pair of vertical longitudinal projections 90 formed as part of the inner cylindrical surface of the second cylindrical portion 13 of the valve body. It moves within the valve guide groove 88. These guide pieces 86 and guide grooves 88 position the valve support 20 within the valve body 12 and align the circular valve with the annular valve seat 2.
This prevents the circular valve 18 or valve support 20 from rubbing or galling when lowered to the seating position.

Valve support 20 has an outward projection 92 having a first downwardly sloping cam actuating surface 94 (upper). This camming surface 94 engages an inclined camming surface 104 (upper) of the valve body to compress the circular valve 18 during sealing engagement with the valve seat 22. The valve support also has a second downwardly sloping cam actuating surface 96 (lower) that engages the sloping cam actuating surface 106 (lower) of the valve body for the same purpose. As shown in FIG. 1, first and second cam operating surfaces 1 of a pair of valve bodies
Since 04 and 106 are located outside the fluid passageway 24, they do not obstruct or disrupt the flow of fluid through the fluid passageway.

The annular valve seat 22 of the present invention forms an annular water sealing surface,
This sealing surface is around an axis perpendicular to the valve seat surface. The seat surface is inclined at 0-10 degrees; in the embodiment of the invention, the sealing surface is frusto-conical with a vertical axis and is inclined at approximately 5 degrees relative to the seat surface. This inclination not only improves the sealing ability between the circular valve and the annular valve seat 22, but also improves the sealing ability of the valve 1 when the valve and valve support are moved downward into watertight engagement with the valve body 12.
This has the effect of preventing 8 from sticking to the valve seat surface.

The gate valve of the present invention may be used with an external screw or yoke that moves the valve stem 16 up and down to open and close the valve. In this type, the valve stem does not rotate, but the handle may be rotated to move the valve stem up and down. As shown in FIG. 1, the threaded portion of the valve stem is outside the valve body. In this case, the threaded part is not exposed to the fluid passing through the valve, so it will not rust, corrode or wear out.
Or, there are no problems inherent to gate valves with fixed valve stems (that do not move up and down). Additionally, the threaded portion of the valve stem of the present invention is external so that it can be periodically inspected and refilled with lubrication if necessary during use, whether the valve is in the closed or open position.

The operation will be explained below. Gate valve 10 is installed in a fluid system or piping system in a conventional manner. The upstream or high pressure side is coupled to the first flange 26 so that high pressure fluid enters the inlet 28 and flows into the first flange 26.
Fluid flows from right to left in the diagram.

When the valve 10 is fully open, the valve support 20 and the circular valve 18 are completely separated from the fluid flow section, thereby reducing fluid turbulence within the flow path. In the case of Chapman-type valves or similar valves, fluid turbulence usually occurs because the valve member does not completely exit the flow path when the valve opens.

The gate valve 10 of the present invention includes a back seal function consisting of an upper annular watertight portion 52 formed as part of the valve stem 16 and a valve stem seat 54 on the lid. When the valve 10 is in the fully open position, the annular watertight portion 52 engages with the valve stem seat 54 of the lid portion, and has a water sealing effect to prevent fluid from flowing out. At the fully open position of the valve 10,
The packing member 56 can be removed even during use,
It can be inspected or replaced.
This is a substantial time and labor savings compared to other valves that must be removed from the flow path and returned to the factory for periodic inspection, maintenance, and replacement.

To close the gate valve 10, rotating the handle 66 lowers the valve stem 16, thus lowering the valve support 2.
0 is lowered to engage the valve body 12, and the valve support 20
engages the annular valve seat 22. As shown in Figure 1, the annular valve seat surface is at a first angle of about 0-10 from the valve stem axis.
degree, preferably 5°. Additionally, the inclined cam actuating surfaces 104 and 106 of each valve body are arranged at a second angle of approximately 15-45 degrees from the valve stem axis in a direction opposite the valve seat surface.
Preferably it is inclined by 30°. Therefore, a wedge-shaped (V-shaped) portion is formed in which the valve support 20 is inserted.
and the circular valve 18 engages. This embodiment is designed to minimize the shear force between the circular valve 18 and the annular valve seat 22 when they engage with each other.

Since the circular valve 18 is limited in free movement relative to the valve support 20, each time the valve is seated or unseated from the annular valve seat 22, the valve rotates a small amount relative to the valve support.

With limited free movement, valve 18 rotates about a horizontal axis approximately 5 degrees from center and when valve 18 and valve support 20 are lowered into water-tight engagement with the valve body, the valve An optimal natural seating position can be taken and the valve seat 22 can be seated evenly around the valve seat 22.

As can be seen in FIG. 1, when the valve 18 and valve support 20 are lowered to the valve closed position, the first and second inclined cam actuating surfaces 94 and 96 of the valve support simultaneously engage the opposing valve body. The first and second cam actuating surfaces 104 and 106 are engaged to move the valve support and circular valve to the left into sealing engagement with the valve seat 22. The first part of the valve body
and second cam actuating surfaces 104 and 106 (as well as mating first and second valve support sloped surfaces 94 and 96).
is inclined from the vertical axis at a second angle, preferably about 30° from the vertical, for changing the direction of the applied force along the vertical axis of the valve stem to a direction substantially perpendicular to the plane of the valve seat 22; Become. This 30 degree angle of inclination multiplies the forces acting along the valve stem 16 and provides a strong force to press the valve 18 against the valve seat 22. This increase in pressure improves the water sealing effect. The forces exerted on the valve support 20 by the first and second cam actuating surfaces 104 and 106 of the valve body are transmitted to the valve 18 approximately at the center of the point of contact between the valve support 20 and the valve body 12.
In this manner, the force that crimp the valve 18 during sealing engagement with the valve seat 22 acts along the geometric center of the circular valve (along the central axis of the valve's threaded shaft 100) and is uniform. Provides water sealing power.

When all the water-sealing engagement surfaces (first and second valve support cam surfaces, first and second cam surfaces of the other valve body, circular valve and valve seat) are engaged, the side of the valve relative to the valve seat is engaged. Movement in the direction (shear direction) is minimized, and excessive friction and wear on these water sealing surfaces can be reduced.

In FIG. 1, when the circular valve 18 is seated on the valve seat 22, high pressure inside the valve is applied to the back of the valve 18, the flow path 24 on the right side of the valve, the second cylindrical portion 13 of the valve body, and the lid portion 1.
It acts inside the valve formed by 4. This high pressure is maintained by the sealing engagement force between the circular valve 18 and the valve seat 22, the lid gasket 38, the annular packing 56, and the like. It should be noted that when high pressure is applied to the back surface of the circular valve 18, this high pressure compresses the valve against the valve seat and facilitates the water sealing effect. This method creates a tighter seal between the valve and the valve seat, and an effective seal cannot be expected when high pressure is on the opposite side of the valve.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing the gate valve of the present invention in a closed state, and FIG. 2 is the gate valve of the present invention, showing the line 2-
3 is a horizontal sectional view taken along line 3--3, and FIG. 4 is a partial vertical sectional view showing the connection relationship between the valve stem and the valve support. 12... Valve body, 13... Second cylindrical part, 14...
... Lid part, 15 ... Valve storage chamber, 16 ... Valve stem, 18
... circular valve, 20 ... valve support body, 22 ... valve seat,
24... Internal cylindrical surface (fluid passage), 28... Inflow section, 32... Outflow section, 42... Annular gasket,
46... T-shaped part, 56... Packing member, 58
...Top of the lid, 66...Handle.

Claims (1)

[Scope of Claims] 1 (a) A valve body forming an inlet and an outlet having a common axis, the valve body further having a long axis substantially perpendicular to the common axis, and having a long axis substantially perpendicular to the common axis; The valve body defines an annular valve seat around at least one of the inlet and outlet portions, the valve seat being in a plane inclined at a first angle with respect to the longitudinal axis, and the valve seat being truncated. The valve body is formed to form a cone-shaped water sealing surface, the water sealing surface being generated around an axis disposed substantially perpendicular to the inclined surface, and the valve body being formed in a direction opposite to the direction of the valve seat surface. forming first and second cam actuating surfaces inclined at a second angle with respect to the longitudinal axis in a direction, the two cam actuating surfaces being respectively outside of the flow path formed by the inlet and the outlet; a second valve body located above and below, the second valve body forming a valve chamber communicating with the inflow and outflow channels; (b) attached to the second valve body so as to form the valve chamber; (c) a valve closing member, the valve support having a flat front surface, the flat surface being inclined by the first angle with respect to the central axis of the valve support; a vertical arcuate member having a mounting hole extending vertically through the front face and disposed proximate the hole on either side of the mounting hole; forming first and second cam actuating surfaces that engage a second cam actuating surface, each of the cam actuating surfaces of the valve support being inclined at the second angle with respect to the central axis; ) a circular valve having a mounting shaft formed with a geometric center forming a plane and perpendicular to the circular valve face, the circular valve having an axis extending through the mounting hole perpendicular to the front face of the valve support; moved and held by the valve support in a loose manner relative to the valve body and the valve support for limited free movement relative to the valve support, and the circular valve face is moved and held by the valve support in a loose manner relative to the valve body and the valve support; disposed essentially parallel to a plane, the circular valve being rotatable about the mounting hole axis to engage the valve seat and uniformly disposed to prevent fluid outflow of the fluid passageway. (c) a valve stem having an axis coextensive with the longitudinal axis of the valve body, the stem extending through the lid and the valve chamber; moving the valve support up and down by means allowing limited movement of the valve support relative to the valve stem in a plane perpendicular to the valve stem axis; (d) is threadedly engaged with the lid so that it can be moved up and down with respect to the valve body flow path, and (d) is arranged around the valve stem within the lid to prevent fluid from flowing out. and (e) the valve stem when the valve stem is in the uppermost position in order to seal the valve chamber with water when the packing is removed and replaced with the circular valve left in place during use of the valve. 1. A gate valve comprising a back water seal portion formed by a portion of the lid portion and a portion of the lid portion. 2. The gate valve according to claim 1, wherein the second angle is larger than the first angle. 3. The gate valve of claim 2, wherein the first angle is within the range of 0-10 degrees and the second angle is within the range of 15-45 degrees.