High-temperature and high-pressure steam trap

Abstract

The utility model relates to a high-temperature high-pressure steam trap which comprises a valve body, a valve seat, a valve core, a valve cover and a valve rod, the valve body adopts a forged steel piece, the valve seat is arranged between an inlet and an outlet of the valve body, an inlet channel of the valve body is positioned above a sealing surface of the valve seat, and a throttling cylinder is arranged at an outlet of the valve seat to reduce the flow rate of condensed water passing through the valve seat. The sealing surface of the valve seat is prevented from being damaged by vaporization and flash evaporation of condensed water at the valve seat; the guide cylinder is installed on the valve seat in a pressing mode through the locking ring, so that the valve seat sealing gasket and the valve deck sealing gasket are independently pressed and sealed, and the situation that the sealing performance between the valve seat and the valve body and between the valve deck and the valve body is affected by part machining errors is avoided. The sealing performance is reliable, and the service life of the product is long.

Description

Technical Field

[0001] The utility model belongs to the field of valves, and in particular relates to a steam trap valve. The utility model is suitable for a steam trap valve of a high-temperature and high-pressure main steam pipeline of a power plant. Background Art

[0002] On the main steam pipeline of the power plant, a steam trap needs to be installed to discharge the high-temperature condensate in the pipeline. At present, the steam trap used in the main steam pipeline of the power plant generally adopts a high-temperature and high-pressure stop valve, whose structure includes a valve body, a valve seat, a valve core, a valve stem, and a valve cover. The valve core adopts a plunger structure to connect with the lower end of the valve stem. A guide cylinder with a pressure reducing hole is set between the valve seat and the valve cover to improve the stability of the valve core movement, reduce the medium pressure passing through the valve seat, and reduce the scouring of the valve seat sealing surface. However, the steam trap on the existing main steam pipeline mainly has the following problems: 1. The pressure difference and flow rate of the high-temperature condensate entering the valve seat after passing through the guide cylinder are very large, which will cause vaporization and flashing at the valve seat, causing damage to the valve seat sealing surface and affecting the service life of the product; 2. The guide cylinder is pressed and installed on the valve seat by the valve cover, and the sealing gasket between the valve cover and the valve body and the sealing gasket between the valve seat and the valve body are pressed by the valve cover at the same time to achieve sealing, which requires high precision of the part size. The part size error can easily cause the two gaskets to be compressed inconsistently and cause leakage. Utility Model Content

[0003] The utility model aims to solve the problems existing in the prior art and to provide a high-temperature and high-pressure steam trap which can prevent condensed water from vaporizing and flashing at the valve seat position, wherein the sealing gasket between the valve body and the valve seat and the valve cover is not affected by the size error of the parts, has reliable sealing performance and a long product service life.

[0004] The technical solution to achieve the purpose of this utility model is:

[0005] A high-temperature and high-pressure steam trap comprises a valve body, a valve seat, a valve core, a valve cover and a valve stem. The valve body is made of forged steel. The valve seat is installed between the inlet and outlet of the valve body. A valve seat sealing gasket is arranged between the valve seat and the valve body. The inlet channel of the valve body is located above the sealing surface of the valve seat. The valve core is made of a cylindrical structure and is fixedly installed at the lower end of the valve stem. A guide cylinder is arranged above the valve seat. A pressure reducing hole connected to the inlet channel is arranged in the circumferential direction of the guide cylinder. The outer cylindrical surface of the valve core is movably matched with the inner hole wall of the guide cylinder. A self-sealing device is arranged between the valve cover and the middle cavity of the valve body. The valve body is characterized in that a throttling cylinder extending into the outlet channel of the valve body is arranged at the lower end of the valve seat. A plurality of throttling holes are arranged in the circumferential direction of the throttling cylinder. A collecting chamber is arranged in the outlet channel of the valve body on the outer circumference of the throttling cylinder. The guide cylinder is pressed and installed on the valve seat by a locking ring, and the locking ring is threadedly matched with the inner wall of the middle cavity of the valve body.

[0006] In the above technical solution, a conical sealing surface is arranged on the outer circumference of the lower part of the valve core cylinder, and the valve seat sealing surface is welded with hard alloy to form a conical sealing surface that cooperates with the valve core sealing surface.

[0007] In the above technical solution, a flexible connection mechanism is used between the valve stem and the valve core, and the flexible connection mechanism is composed of a disc spring arranged between the lower end surface of the valve stem and the valve core.

[0008] The beneficial effects of the utility model compared with the prior art are:

[0009] 1. A throttling cylinder is set at the outlet of the valve seat to block the condensed water passing through the valve seat in the throttling cylinder, reduce the flow rate of the condensed water through the valve seat, and make the condensed water enter the outlet channel through the throttling cylinder to vaporize, so as to prevent the condensed water from vaporizing and flashing at the valve seat to damage the valve seat sealing surface, thereby improving the service life of the product;

[0010] 2. The guide cylinder is installed on the valve seat by means of a locking ring, so that the valve seat and the valve cover form independent sealing structures with the valve body, thus avoiding the sealing performance between the valve seat and the valve body being affected by the axial position of the valve cover, and the sealing performance is reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the utility model.

[0012] In the figure: 1 valve body, 2 valve seat gasket, 3 valve seat, 4 valve core, 5 valve core mounting ring, 6 guide cylinder, 7 locking ring, 8 valve stem, 9 valve cover, 10 self-tightening sealing ring, 11 four open rings, 12 support plate, 13 packing seat, 14 packing, 15 packing gland, 16 packing pressure plate, 17 anti-rotation clamp, 18 connecting flange, 19 column, 20 pressure reducing hole, 21 throttling hole, 22 throttling cylinder, 23 manifold. DETAILED DESCRIPTION

[0013] like Figure 1The high-temperature and high-pressure steam trap comprises a valve body 1, a valve seat 3, a valve core 4, a valve cover 9, and a valve stem 8. The valve body 1 is made of forged steel and has high temperature and high pressure resistance. The valve seat 3 is installed between the inlet and outlet channels of the valve body 1. A valve seat sealing gasket 2 is arranged between the valve seat 3 and the valve body 1 to achieve sealing between the outer periphery of the valve seat 3 and the valve body 1. The inlet channel of the valve body 1 is located above the sealing surface of the valve seat 3, that is, the medium flows in from the top of the valve seat 3 and flows out from the bottom. The valve core 4 adopts a cylindrical structure and is connected by a valve core mounting ring 5 and The upper end screw hole of the valve core 4 is threadedly connected to fix it on the annular convex shoulder at the lower end of the valve stem 8. The valve core 4 and the valve stem 8 can also adopt an integrated structure. A guide cylinder 6 is arranged above the valve seat 3. The guide cylinder 6 is provided with a pressure reducing hole 20 connected to the inlet channel in the circumferential direction. There are several pressure reducing holes 20, which are evenly distributed in the circumferential direction of the guide cylinder 6 at the outlet channel position. The high-pressure medium of the inlet channel is decompressed and flows into the valve seat 3. The outer cylindrical surface of the valve core 4 is movably matched with the inner hole of the guide cylinder 6 to guide and position the valve core 4. To improve the stability of the valve core 4, a self-sealing device is provided between the valve cover 9 and the middle cavity of the valve body 1 to achieve the sealing between the valve cover 9 and the valve body 1, and a packing sealing device composed of a packing seat 13, a packing 14, a packing gland 15, and a packing pressure plate 16 is provided between the valve stem 8 and the valve cover 9; the feature is that a throttling cylinder 22 extending into the outlet channel of the valve body 1 is provided at the lower end of the valve seat 3, and a plurality of throttling holes 21 are provided in the circumferential direction and the bottom of the throttling cylinder 22 to limit the flow of condensed water passing through the valve seat 3, thereby preventing When the condensed water passes through the valve seat 3, it vaporizes and flashes, which protects the sealing surface of the valve seat 3. A collecting chamber 23 is set in the outlet channel of the valve body 1 on the outer circumference of the throttling cylinder 22. The medium flows into the outlet channel from the throttling hole 21 through the collecting chamber 23 and vaporizes, thereby reducing the vaporization noise and vibration. The guide cylinder 6 is tightly installed on the upper end face of the valve seat 3 by using a locking ring 7. The valve seat sealing gasket 2 is reliably pressed, thereby improving the sealing reliability between the valve seat 3 and the valve body 1. The locking ring 7 is threadedly connected to the inner wall of the middle cavity of the valve body 1.

[0014] A conical sealing surface is arranged on the outer circumference of the lower part of the cylindrical body of the valve core 4 , and the sealing surface of the valve seat 3 is processed by surfacing hard alloy to form a conical sealing surface that cooperates with the sealing surface of the valve core 4 .

[0015] A flexible connection mechanism is used between the valve stem 8 and the valve core 4. The flexible connection mechanism is composed of a disc spring set between the lower end surface of the valve stem 8 and the valve core 4. When closing, the impact force between the valve core 4 and the sealing surface of the valve seat 3 is reduced, thereby increasing the service life of the product.

[0016] The self-sealing device consists of a self-tightening sealing ring 10, a four-open ring 11, and a support plate 12. The self-tightening sealing ring 10 is installed between the outer cylindrical surface of the valve cover 9 and the inner wall of the middle cavity of the valve body 1. The lower end of its inner hole is matched with the valve cover 9 by an inclined surface, and the upper end surface is pressed and connected with the lower end surface of the four-open ring 11. The support plate 12 is installed in the upper plane of the four-open ring 11. The bolts pass through the through holes of the support plate 12 and are threadedly connected to the valve cover 9. The self-tightening sealing ring 10 is tightened and installed between the valve cover 9 and the valve body 1. The medium pressure pushes the valve cover 9 to move upward, and the self-tightening sealing ring 10 is wedged between the valve cover 9 and the valve body 1 to achieve self-sealing of the middle cavity. A number of disassembly holes are provided on the valve body 1 outside the four-open ring 11 to facilitate the disassembly of the four-open ring 11.

[0017] A plurality of columns 19 are installed on the upper end surface of the middle cavity of the valve body 1. A connecting flange 18 is fixedly installed on the upper end of the column 19. An actuator is installed on the upper end of the connecting flange 18. The actuator adopts an electric actuator, a hydraulic actuator or a pneumatic actuator. An anti-rotation clamping plate 17 is arranged between the valve stem 8 and the column 19 to prevent the valve stem 8 from rotating.

Claims

1. A high-temperature and high-pressure steam trap, comprising a valve body (1), a valve seat (3), a valve core (4), a valve cover (9), and a valve stem (8), wherein the valve body (1) is made of forged steel, the valve seat (3) is installed between the inlet and outlet passages of the valve body (1), a valve seat sealing gasket (2) is arranged between the valve seat (3) and the valve body (1), the inlet passage of the valve body (1) is located above the sealing surface of the valve seat (3), the valve core (4) is made of a cylindrical structure and is installed at the lower end of the valve stem (8), a guide cylinder (6) is arranged above the valve seat (3), a pressure reducing hole (20) in the circumferential direction of the guide cylinder (6) is arranged which is connected to the inlet passage, the outer cylindrical surface of the valve core (4) is movably matched with the inner hole wall of the guide cylinder (6), and a self-sealing device is arranged between the valve cover (9) and the inner wall of the middle cavity of the valve body (1); wherein: A throttling cylinder (22) extending into the outlet channel of the valve body (1) is provided at the lower end of the valve seat (3); a plurality of throttling holes (21) are provided in the circumferential direction and at the bottom of the throttling cylinder (22); a collecting chamber (23) is provided in the outlet channel of the valve body (1) on the outer circumference of the throttling cylinder (22); the guide cylinder (6) is pressed and installed on the upper end surface of the valve seat (3) by a locking ring (7); the locking ring (7) is threadedly connected to the inner wall of the middle cavity of the valve body (1).

2. The high-temperature and high-pressure steam trap according to claim 1, characterized in that: A flexible connection mechanism is used between the valve stem (8) and the valve core (4), wherein the flexible connection mechanism is composed of a disc spring arranged between the lower end surface of the valve stem (8) and the valve core (4).

3. The high-temperature and high-pressure steam trap according to claim 1 or 2, characterized in that: A conical sealing surface is provided on the outer circumference of the lower part of the cylindrical body of the valve core (4), and the sealing surface of the valve seat (3) is processed by surfacing hard alloy to form a conical sealing surface that cooperates with the sealing surface of the valve core (4).

4. The high-temperature and high-pressure steam trap according to claim 3, characterized in that: The self-sealing device comprises a self-tightening sealing ring (10), a four-open ring (11), and a support plate (12). The self-tightening sealing ring (10) is installed between the outer cylindrical surface of the valve cover (9) and the inner wall of the middle cavity of the valve body (1). The lower end of the inner hole of the self-tightening sealing ring (10) is matched with the valve cover (9) by an inclined surface, and the upper end surface is pressed and connected with the lower end surface of the four-open ring (11). The support plate (12) is installed in the upper end surface of the four-open ring (11). Bolts pass through the through holes of the support plate (12) and are threadedly connected with the valve cover (9). The self-tightening sealing ring (10) is tightened and installed between the valve cover (9) and the valve body (1). A plurality of disassembly holes are provided on the valve body (1) outside the four-open ring (11).

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