CN103527787A - Metal seal ring convenient to dismantle and power station regulating valve with metal seal ring - Google Patents

Abstract

The invention relates to a metal seal ring. The metal seal ring is characterized in that the seal ring is annular, the lower end of the seal ring is provided with a wedge-shaped sharp part, the upper end of the seal ring is provided with an annular rib edge protruded in the radial direction, and the upper surface of the annular rib edge is of a self-centering spherical surface or conical surface structure. The metal seal ring has the advantages that when the seal ring is applied to a valve, a pressing flange can still be automatically aligned with the seal ring when being not horizontal, circumferential stress balance is promoted, and a sealing stress state is improved. The upper annular rib edge of the seal ring enables the seal ring to provide a dismantling strength point and simultaneously has the effect of a reinforcing rib; not only is structural rigidity improved, but also seal ring machining, valve assembly and valve dismantling are facilitated, machining clamp design is simplified, machining precision is improved, and sealing performance is guaranteed finally.

Description

The metal sealing ring that is easy to disassemble and the power station control valve using the metal sealing ring

technical field

The invention relates to a sealing ring, and also relates to a power station regulating valve adopting a sealing ring structure.

Background technique

The power station control valves used for thermal power steam units are mainly distributed in the three major systems of boilers, steam turbines and auxiliary machines. The thermal control technology of thermal power plants generally takes the safe and economical operation of the unit as the main goal, and various regulating valves become special auxiliary equipment for safe operation. The higher the parameters of the unit, the greater the capacity of the unit, and the higher the performance requirements for the power station control valve (including: minimum flow valve, feed water bypass control valve, desuperheating water control valve, etc.), such as sealing performance, regulation characteristics, and reliability requirements.

For example: in the current power station control valve structure, the external sealing of the valve body and the bonnet adopts a wedge-shaped sealing ring structure at the upper end plane and the lower end. After the mouth is pressed tightly, the wedge-shaped tip at the lower end expands to realize the external sealing of the valve body and the valve cover. Although it can meet the sealing requirements to a certain extent, it also has certain disadvantages: it will be very difficult to disassemble and disassemble the valve due to the swelling and crushing of the wedge-shaped tip. Moreover, due to structural reasons, this kind of sealing ring has poor rigidity, is extremely easy to deform, has poor processing technology, and has high requirements for fixture clamping, which is not conducive to improving the processing accuracy, and it is difficult to ensure the sealing performance required by the design. Therefore, it is imperative to develop a new sealing ring structure that is easy to disassemble, has good sealing performance, high rigidity, and is easy to clamp and process.

Contents of the invention

The technical problem to be solved by the present invention is to provide a metal sealing ring which is easy to disassemble, has good sealing performance, high rigidity and is not easily deformed by machining and clamping, and also provides a power station regulating valve adopting the structure of the metal sealing ring.

In order to solve the above technical problems, the technical solution of the present invention is: a metal sealing ring that is easy to disassemble. The annular rib is out, and the upper surface of the annular rib is a self-centering spherical or conical structure.

Preferably, the lower end side of the sealing ring is provided with an annular groove, and the annular groove is located on the flat surface of the non-wedge inclined side of the sealing ring.

Preferably, the annular groove is an arc-shaped groove, and its arc radius R is 3-5mm.

A power station regulating valve adopting the above-mentioned metal sealing ring structure, its innovative point is that it includes a valve body, a valve cover, a compression flange, a sealing ring, a valve cover, the lower end of the valve cover extends into the hollow upper part of the valve body, and the valve cover The lower end has a radially protruding annular flange, and the upper surface of the annular flange is an annular conical surface; the sealing ring, the lower end of the sealing ring has a wedge-shaped tip, and the upper end has a radially protruding annular rib side, and the upper surface of the annular rib is a self-centering spherical or conical surface structure; compression flange, the junction of the inner ring of the compression flange and the lower end surface is provided with a circle of annular inlay grooves matching the upper end of the sealing ring; The compression flange is fixed on the upper end surface of the valve body through bolts and nuts, and the annular rib at the upper end of the sealing ring is evenly pressed through the annular inlay groove to realize the sealing between the valve cover and the valve body.

The advantage of the present invention is that: the upper part of the sealing ring is a self-centering spherical or conical structure, that is, the top contour is designed as a conical or spherical surface, so that even if the upper flange or gland used for compression is not horizontal during installation, it can Realize the automatic alignment with the sealing ring, and promote the balance of force in one week. At the same time, the flange or gland used for compression is automatically centered, the contact area is increased, the contact pressure stress is reduced, and the stress state of the seal is more reasonably improved.

The upper annular rib of the sealing ring enables the sealing ring to provide a point of disassembly, and at the same time acts as a reinforcing rib; it not only improves the rigidity of the structure, but also facilitates the machine clamping of the sealing ring, valve assembly and valve disassembly, and simplifies the machining fixture Design, improve machining accuracy, and finally guarantee the sealing performance. And the lower end side of the sealing ring is provided with an annular groove, when the flange is pressed to compress the sealing ring, the lower end of the sealing ring can be smoothly deformed and sealed to improve the sealing effect.

The sealing ring is a key part of this type of product and can be widely used in various power station valve products, especially for thermal power generation steam units as minimum flow regulating valves, desuperheating water regulating valves, feed water bypass regulating valves, and high-temperature, high-pressure and high-pressure valves for power stations. Differential traps and other products are used to regulate flow, pressure and media isolation.

Description of drawings

Fig. 1 is a structural schematic diagram of a metal sealing ring in the present invention.

Fig. 2 is a schematic structural diagram of an embodiment of a power station regulating valve of the present invention.

Detailed ways

The present invention discloses a novel metal sealing ring structure, which, as shown in Figure 1, has a wedge-shaped tip 8a at the lower end of the sealing ring 8, and a radially protruding annular rib 8b at the upper end, and the annular rib The upper surface of the side 8b is a self-centering spherical or conical structure. An annular groove 8c is provided on the lower end side of the sealing ring 8, and the annular groove 8c is located on the straight surface of the non-wedge-shaped slope side of the sealing ring.

the

This embodiment is a structural design diagram applied to a minimum flow regulating valve of a power station. Please refer to Figure 1 and 2, including valve body 1, throttle plate 4, valve core 5, balance seal ring 7, seal ring 8, valve stem 10, valve cover 11, packing gland 14, packing 15, packing 16, nut 18, bolt 19, compression flange 20, and cap 22.

A valve cover 11 is installed on the top of the middle hole of the valve body 1, and the lower end of the valve rod 10 passes through the valve cover 11 and stretches into the inner chamber of the valve body 1, and the lower end of the valve rod 10 is connected with the valve core 5 built in the valve body. The end surface of the lower part of the valve stem 10 and the valve core adopt a conical design. When mating, the conical surface has an automatic alignment function, which effectively eliminates the concentricity error after the valve core and the valve rod are connected. The upper part of the spool 5 adopts a joint cap 22 to hold the spool 5 and the valve stem 10 tightly. Specifically, the parallel cap 22 is threadedly connected to the valve stem 10, and when the parallel cap 22 rotates, it will automatically hold tightly to the valve stem 10 to eliminate the gap between the two. After tightening, the elastic pin 9 is used to lock the valve stem to prevent loose. In addition, a balance sealing ring 7 is designed on the outer circle of the valve core 5 to assist the sealing of the valve cover and the valve core, and at the same time, it is equivalent to a bearing to ensure a more stable up and down movement of the valve core.

A valve seat 3 is installed on the lower part of the middle hole of the valve body 1, a throttling disk 4 is installed on the valve seat 3, and a lower sealing ring 2 is arranged between the valve seat 3 and the valve body 1. Among them, the valve core 5, the valve seat 3, and the lower sealing ring 2 form the main seal of the valve, and the corners of the lower end face of the valve core are designed as conical surfaces, which correspond to the corners of the inner hole of the valve seat 3 to form the main sealing pair. When the spool is in contact with the valve seat, the valve is in a sealed closed state; when the two are separated, the valve is in an open state. The valve core 5 and the throttle plate 4 constitute a throttle assembly, and when the valve core moves up and down, it corresponds to different openings of the throttle plate to realize the adjustment of the flow rate.

When opening, the valve rod 10 moves up first, and drives the valve core 5 to move up and down, so as to realize opening adjustment. A balance hole A is opened at the upper end of the spool 5, which eliminates the pressure in the upper cavity of the spool and realizes the opening of the spool without pressure difference, which is beneficial to reduce the thrust of the actuator, thereby reducing the cost of product configuration.

A packing 15 and a packing 16 are arranged between the valve cover 11 and the valve stem 10, and the packing 15 and 16 are pressed together by the packing gland 14 and the bolt 13 and the nut 12, thereby constituting the external seal of the valve stem 10, so as to prevent the valve stem from moving up and down. cause leakage.

The lower end of the valve cover 11 has an annular flange protruding radially, and the upper surface of the annular flange is an annular conical surface.

The lower end of the sealing ring 8 has a wedge-shaped tip 8a, and the upper end has a radially protruding annular rib 8b, and the upper surface of the annular rib 8b is a self-centering spherical or conical surface structure. An annular groove 8c is provided on the lower end side of the sealing ring 8, and the annular groove 8c is located on the straight surface of the non-wedge-shaped slope side of the sealing ring.

As a more specific embodiment of the present invention: the annular groove 8c is an arc-shaped groove, and the radius R of the arc is 3-5 mm.

The junction of the inner ring and the lower end surface of the compression flange 20 is provided with an annular mosaic groove matching the upper end of the sealing ring; The groove evenly presses the upper annular rib of the sealing ring 8 to realize the sealing between the valve cover 11 and the valve body 1 .

the

working principle:

The driving device is connected to the valve stem. When the valve stem moves downward, the flow area of the throttling part decreases, and the output flow of the valve decreases. When the valve core moves to the bottom, the main sealing pair closes first, and the valve is in a closed state. When it is opened, the valve stem drives the valve core to open, and since the valve core moves in a state of no pressure difference, the working thrust of the actuator is reduced. With the upward movement of the valve core, the area of the flow channel of the throttling piece gradually increases, and the flow rate of the valve increases correspondingly, so as to realize the regulation and control of the flow rate of the valve.

Sealing principle:

The upper part of the sealing ring is a self-centering spherical or conical structure, that is, the top contour is conical or spherical, and the corresponding inlay groove is set on the compression flange, which can also be realized when the compression flange is not horizontal. The sealing ring is automatically aligned.

The upper annular rib of the sealing ring acts as a reinforcing rib and at the same time enables the sealing ring to provide a point of disassembly, which can simplify the design of machining fixtures, improve machining accuracy, and ensure the sealing performance. And the lower end side of the sealing ring is provided with an annular groove, when the flange is pressed to compress the sealing ring, the lower end of the sealing ring can be smoothly deformed to the side of the annular groove to achieve better sealing.

Those skilled in the art should understand that the above embodiment of the power station regulating valve using the sealing ring structure is only illustrative and not limiting. The sealing ring is not only suitable for this type of regulating valve, but also suitable for other types of valves. The body is sealed externally.

Claims (4)

1. a metal o-ring for convenient disassembly, is characterized in that: described seal ring is annular, and its lower end has a wedge shape tip, and upper end has a ring rib limit of radially protruding, and the upper surface on this ring rib limit is self contering sphere or cone structure.

2. seal ring according to claim 1, is characterized in that: the lower end side of described seal ring is provided with a ring annular groove, and this circular groove is positioned at the flat face of the non-wedge shape of seal ring inclined-plane side.

3. seal ring according to claim 1, it is characterized in that: described circular groove is arc-shaped slot, and its radius of arc R is 3 ~ 5mm.

4. adopt a control valve for power station for above-mentioned metal sealing coil structures, it is characterized in that: comprise valve body, valve gap, supported flange, seal ring,

Valve gap, valve body hollow, upper is stretched in the lower end of valve gap, and the lower end of valve gap has an annular flange flange extending radially, and the upper surface of this annular flange flange is a circular cone;

Seal ring, seal ring lower end has a wedge shape tip, and upper end has a ring rib limit of radially protruding, and the upper surface on this ring rib limit is self contering sphere or cone structure;

Supported flange, the inner ring of supported flange and lower end surface intersection are provided with the annular embedding groove that a circle and seal ring upper end match; Supported flange is fixed on the upper-end surface of valve body by bolt, nut, and by the ring rib limit, upper end of the even press seal circle of annular embedding groove, realizes the sealing of valve gap and valve body.

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