A cryogenic axial flow check valve with online maintenance function

Abstract

A cryogenic axial flow check valve with online maintenance function includes a valve body, a guide sleeve, a valve cover, and a valve disc. The valve cover is a top-mounted valve cover, a support rib is provided on the valve cover, two support ribs are provided inside the valve body, and three support grooves corresponding to the support ribs are provided on the guide sleeve. An anti-rotation block fixed to the guide sleeve by screws II is provided in the guide sleeve support groove. A guide frame is provided inside the guide sleeve, and bearings are provided at the head and tail of the guide frame. A spring is provided between the guide frame and the valve disc, and the spring is installed in the limiting hole of the guide frame and the valve disc. A raised rib is provided on the valve disc and the guide sleeve, and a corresponding pin shaft hole is provided on the raised rib. A guide cone is provided at the tail of the guide sleeve, a metal wound gasket and a pan plug are provided between the valve seat and the valve body, and a wound gasket is provided between the valve body and the valve cover. The beneficial effect of the present invention is that the online maintenance function can be realized through the design of the top-mounted valve cover.

Description

Technical Field

[0001] The invention relates to a check valve, in particular to a cryogenic axial flow check valve with an online maintenance function. Background Art

[0002] In LNG receiving stations, cryogenic axial flow check valves are used at the pump outlets and compressor unit outlets for transporting LNG to prevent the backflow of the medium. Cryogenic axial flow check valves are connected by butt welding according to the requirements of the receiving station. After the general axial flow check valve is welded to the pipeline, when the valve fails (stuck action and seal failure, etc.) and needs to be repaired, the valve can only be cut out as a whole for repair. Since the valve has a smaller structural length after cutting, it is necessary to weld on both ends of the valve and process the corresponding groove envelope before re-welding it to the pipeline after repair, which cannot meet the requirements of online maintenance functions. Summary of the invention

[0003] In order to overcome the above-mentioned problems in the prior art, the present invention provides a cryogenic axial flow check valve with an online maintenance function.

[0004] The technical solution of the present invention is a cryogenic axial flow check valve with online maintenance function, comprising a valve body, a guide sleeve, a valve cover, and a valve disc. The valve cover is a top-mounted valve cover, a supporting rib is provided on the valve cover, two supporting ribs are provided inside the valve body, and three supporting grooves corresponding to the supporting ribs are provided on the guide sleeve. An anti-rotation block fixed to the guide sleeve by screws II is provided in the support groove of the guide sleeve. A guide frame is provided inside the guide sleeve, bearings are provided at the head and tail of the guide frame, a spring is provided between the guide frame and the valve disc, and the spring is installed in the limiting holes of the guide frame and the valve disc, raised ribs are provided on the valve disc and the guide sleeve, and corresponding pin shaft holes are provided on the raised ribs, a guide cone is provided at the tail of the guide sleeve, a metal winding gasket and a pan plug are provided between the valve seat and the valve body, which are fixed by a valve seat fixer and screws I, a winding gasket is provided between the valve body and the valve cover, and they are fixedly connected by fasteners.

[0005] Furthermore, the three supporting ribs are evenly distributed, and the angle between any two of them is 120°.

[0006] Furthermore, the flood plug is a back-to-back flood plug.

[0007] Beneficial effects of the present invention:

[0008] The design of the top-mounted bonnet enables online maintenance; the guide sleeve is designed as a single component and installed on the support ribs inside the valve body to achieve a detachable function. The axial direction of the guide sleeve is limited by the support ribs on the valve body and the bonnet. An anti-rotation block is provided in the support groove of the guide sleeve to limit its rotation under the force of the medium; raised ribs are machined on the valve disc and the guide sleeve, and the raised ribs are provided with corresponding pin holes. The spring is tightened with a nut to fix the valve disc and the guide sleeve in a certain position and then removed; the valve seat is designed with a double seal structure of a metal wound gasket and a pan plug to make its seal more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the structure of the present invention;

[0010] Figure 2 for Figure 1 Middle AA section view;

[0011] Figure 3 It is a three-dimensional schematic diagram of the position of the anti-rotation block;

[0012] Figure 4 It is a three-dimensional schematic diagram of the positions of two supporting ribs inside the valve body;

[0013] Figure 5 It is a schematic diagram of the sealing structure between the valve body and the valve seat;

[0014] Figure 6 It is the side view of the valve cover;

[0015] Figure 7 This is a schematic diagram of the screenshot of three support ribs.

[0016] In the figure: 1. valve body; 2. guide cone; 3. guide sleeve; 4. guide shaft; 5. guide frame; 6. spring; 7. bearing; 8. valve disc; 9. valve seat holder; 10. screw Ⅰ; 11. valve seat; 12. metal wound gasket; 13. universal plug; 14. wound gasket; 15. fastener; 16. valve cover; 17. pin shaft; 18. nut; 19. anti-rotation block; 20. screw Ⅱ. DETAILED DESCRIPTION

[0017] As shown in the figure, a cryogenic axial flow check valve with online maintenance function includes a valve body 1, a guide sleeve 3, a valve cover 16, and a valve disc 8. The valve cover 16 is a top-mounted valve cover. A support rib is provided on the valve cover 16. Two support ribs are provided inside the valve body 1. The guide sleeve 3 is provided with three support grooves corresponding to the support ribs. The three support ribs are evenly distributed, and the angle between each other is 120°, which plays a supporting and axial limiting role for the guide sleeve 3; an anti-rotation block 19 fixed to the guide sleeve 3 by screws Ⅱ20 is provided in the support groove of the guide sleeve 3 to prevent the guide sleeve 3 from rotating under the action of the medium; a guide frame 5 is provided inside the guide sleeve 3, bearings 7 are provided at the head and tail of the guide frame 5, a spring 6 is provided between the guide frame 5 and the valve disc 8, and the spring 6 is installed at the guide frame 5 and the valve disc 8 In the limiting hole, a guide cone 2 is provided at the tail of the guide sleeve 3. When the medium flows back, the medium can only act on the valve disc 8 through the guide cone 2, reducing a certain impact force and playing a role of slow closing; the valve disc 8 and the guide sleeve 3 are provided with raised ribs, and the raised ribs are provided with corresponding pin shaft holes. The spring is tightened by the pin shaft and the nut to fix the valve disc and the guide sleeve at a certain position, which is convenient for taking it out; a metal wound gasket 12 and a flood plug 13 are provided between the valve seat 11 and the valve body 1, which are fixed by the valve seat fixture 9 and the screw Ⅰ10. When the metal wound gasket 12 leaks, the flood plug 13 plays a role in compensating for the leakage; a wound gasket 14 is provided between the valve body 1 and the valve cover 16, which is fixedly connected by the fastener 15. The compression amount of the wound gasket 14 is controlled by the principle of quantitative compression to achieve its sealing.

[0018] When the valve is stuck or the seal fails, the following steps can be used to perform online maintenance:

[0019] Step 1: Remove the fastener 15 between the valve cover 16 and the valve body 1, and remove the valve cover 16 and the wound sealing gasket 14 therebetween;

[0020] Step 2: Install the pin 17 into the corresponding pin holes on the convex ribs on the valve disc 8 and the guide sleeve 3. The tail of the pin 17 is provided with a thread. Use the nut 18 to tighten the spring preload force to open the valve disc 8 to a certain position and fix it together with the guide sleeve 3. Then, remove the valve disc 8 and the guide sleeve 3 as a whole from the supporting ribs inside the valve body and take them out of the valve cavity for the next step of disassembly;

[0021] Step 3: Remove the nut 18, take out the valve disc 8 from the guide frame 5, and take out the spring 8;

[0022] Step 4: Disassemble the guide frame 5 and the guide sleeve 3, remove the guide frame 5, and disassemble the bearings 7 at the head and tail of the guide frame 5;

[0023] Step 5: If the valve seat seal needs to be replaced, remove the screws Ⅰ10 on the valve seat retainer 9 and unscrew the valve seat retainer 9 from the valve body 1;

[0024] Step 6: Remove the valve seat 11, then remove the metal spiral wound gasket 12 and the pan plug 13 to complete the valve disassembly.

[0025] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A cryogenic axial flow check valve with online maintenance function, comprising a valve body, a guide sleeve, a valve cover, a valve disc, and a valve seat, characterized in that: The valve cover is a top-mounted valve cover, and a supporting rib is provided on the valve cover, and two supporting ribs are provided inside the valve body. The guide sleeve is provided with supporting grooves corresponding to three supporting ribs, and an anti-rotation block fixed to the guide sleeve by screws II is provided in the support groove of the guide sleeve. A guide frame is provided inside the guide sleeve, and bearings are provided at the head and tail of the guide frame. A spring is provided between the guide frame and the valve disc, and the spring is installed in the limiting holes of the guide frame and the valve disc. A guide cone is provided at the tail of the guide sleeve, and raised ribs are provided on the valve disc and the guide sleeve, and corresponding pin shaft holes are provided on the raised ribs. A metal wound gasket and a pan plug are provided between the valve seat and the valve body, which are fixed by a valve seat fixer and screws I. A wound gasket is provided between the valve body and the valve cover, and they are fixedly connected by fasteners.

2. A cryogenic axial flow check valve with online maintenance function as claimed in claim 1, characterized in that: The three supporting ribs are evenly distributed, and the angle between any two of them is 120°.

3. A cryogenic axial flow check valve with online maintenance function as claimed in claim 1, characterized in that: The flood plug is a back-to-back flood plug.

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