Method of grinding a safety valve seat

Abstract

A kind of grinding method of safety valve seat, including steps: 1) the safety valve seat to be ground is supported on eccentric positioning disc, and is formed radial positioning by the through hole of bottom and the cooperation of circular cone structure, so that the sealing surface of the safety valve seat to be ground faces upwards;2) one end of pressure block is fixed by screw rod and threaded hole on rotating disc, the other end is pressed on the connecting flange of valve seat, to fix the position of safety valve seat;3) grinding head is pressed on the sealing surface of safety valve seat under the action of gravity;4) rotating disc rotates, drives safety valve seat to eccentric motion, and the motion trail of safety valve seat is located in the projection range of grinding head, until grinding is finished.The present application is simple in operation, safe, can effectively prolong the service life of grinding head, reduce the overhaul and calibration cost of safety valve seat.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical industry, in particular to a kind of safety valve seat grinding method. BACKGROUND

[0002] According to the relevant provisions of national special equipment, safety valve must be periodically inspected (checked once a year), and the unqualified one needs to be overhauled and checked qualified. The overhaul of safety valve mainly lies in the grinding of sealing surface. At present, it is usually hand-held grinding head to draw concentric circle on the valve seat sealing surface for grinding. Due to the small space in the valve body and the small movement surface of the grinding head, the grinding work of the valve seat is relatively large.

[0003] In order to reduce the labor intensity of safety valve overhaul, especially the grinding of safety valve seat, and improve the work efficiency of safety valve overhaul, there are safety valve seat grinders on the market. Its working principle is: the safety valve is placed at the center position of the grinder, the grinder drives the valve body to rotate slowly, and the grinding operator holds the grinding head on the valve seat and keeps the grinding head still (not rotating). This operation method greatly reduces the labor intensity, however, the actual grinding surface of the grinding head used in this maintenance method is almost equal to the sealing surface of the valve seat, which is easy to form pits on the surface of the grinding head, and the grinding head needs to be replaced frequently, resulting in high maintenance cost. In addition, the maintenance worker is close to the rotating body, which is easy to cause injury to the worker.

[0004] Therefore, how to safely and low-cost grind the valve seat of safety valve is a problem to be solved by those skilled in the art. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a kind of safety valve seat grinding method, which is simple and safe to operate, can effectively prolong the service life of the grinding head, and reduce the maintenance and calibration cost of the safety valve seat.

[0006] The technical scheme of the present application is: a kind of safety valve seat grinding method, using the following equipment including steps:

[0007] The device includes a turntable, an eccentric positioning disc, a mounting bracket and a grinding head. The center of the turntable is provided with a mounting hole, and the top surface of the turntable is provided with a plurality of threaded holes. The bottom surface of the eccentric positioning disc is provided with a mounting shaft, and the center is deviated. The grinding head is assembled on the mounting bracket through the mounting rod and is circumferentially limited. It corresponds to the mounting hole of the turntable. The eccentric positioning disc is fixedly arranged on the turntable through the mounting shaft and driven by the turntable to rotate eccentrically,

[0008] 1) Support the safety valve seat to be ground on the turntable, and form radial positioning by cooperating the through hole at the bottom with the eccentric positioning disc, so that the sealing surface of the safety valve seat to be ground faces upward;

[0009] 2) the one end of the pressing block is fixed by screwing with the threaded hole on the rotating disc, and the other end is pressed on the connecting flange of the valve seat of the safety valve to fix the position of the valve seat of the safety valve;

[0010] 3) the grinding head is pressed on the sealing surface of the valve seat of the safety valve under the action of gravity;

[0011] 4) the rotating disc rotates to drive the valve seat of the safety valve to perform eccentric motion, and the motion track of the valve seat of the safety valve is located in the projection range of the grinding head, until the grinding is completed.

[0012] The mounting bracket is in an inverted U-shaped structure, the mounting bracket in the inverted U-shaped structure is fixed on the two sides of the rotating disc and located above the rotating disc, a circumferential positioning sleeve is arranged on the horizontal section of the mounting bracket in the inverted U-shaped structure, and the mounting rod of the grinding head is assembled in the circumferential positioning sleeve to form circumferential limiting.

[0013] The circumferential positioning sleeve is a rectangular tube or a hexagonal tube, and the cross section of the mounting rod of the grinding head is adapted to the cross section of the rectangular tube or the hexagonal tube.

[0014] The eccentric positioning disc is in a circular truncated cone structure.

[0015] The upper part of the eccentric positioning disc is in a circular truncated cone structure, the bottom surface of the circular truncated cone structure has a smaller diameter than the diameter of the eccentric positioning disc, the valve seat of the safety valve to be ground is supported on the eccentric positioning disc, and the valve seat of the safety valve to be ground is radially positioned by cooperating the through hole in the bottom with the circular truncated cone structure in the upper part of the eccentric positioning disc, so that the sealing surface of the valve seat of the safety valve to be ground faces upward.

[0016] A counterweight is fixedly arranged on the eccentric positioning disc.

[0017] The eccentric distance of the mounting shaft deviating from the center is 1 / 8-1 / 5 of the outer diameter of the sealing surface of the valve seat of the safety valve to be ground.

[0018] The threaded holes are arranged in two groups, the number of the threaded holes in each group is multiple, and the threaded holes in each group are uniformly and interval distributed along the radial direction of the rotating disc.

[0019] The number of the pressing blocks is two, each pressing block comprises a first pressing block and a second pressing block, the first pressing block is in an L shape, strip-shaped holes are arranged on the two folded edges of the first pressing block, the first pressing block is fixedly connected with the threaded hole by screwing through the horizontal folded edge, the second pressing block is in an L shape, the vertical folded edge of the second pressing block is fixed on the vertical folded edge of the first pressing block by a bolt, and the horizontal folded edge of the second pressing block is pressed on the connecting flange of the valve seat of the safety valve.

[0020] The above technical scheme has the following beneficial effects:

[0021] 1. The grinding method of the present application can greatly improve the actual grinding area of the grinding head by eccentric grinding, thereby greatly prolonging the service life of the grinding head, reducing the replacement frequency of the grinding head, and further reducing the maintenance and calibration cost of the safety valve seat.

[0022] 2. The device used in the grinding method of the present application has a simple structure and is easy to operate. The eccentric positioning disc and the pressing block quickly and accurately position the safety valve seat to be ground, ensure the stability of the sealing surface of the safety valve seat, and further ensure the grinding accuracy of the sealing surface.

[0023] 3. The device used in the grinding method of the present application can adapt to the installation and positioning of safety valve seats of multiple sizes and specifications by designing the upper part of the eccentric positioning disc as a circular truncated cone, designing multiple threaded holes and pressing blocks with a specific structure, which can effectively reduce the grinding cost of safety valve seats of different sizes and specifications.

[0024] 4. The device used in the grinding method of the present application has the grinding head circumferentially fitted on the mounting bracket and pressed against the sealing surface of the safety valve seat under the action of its own weight, which ensures balanced force application during grinding, adapts to the installation and positioning of safety valve seats of multiple sizes and specifications, and is very convenient to install and disassemble the grinding head, which can effectively reduce the labor intensity and ensure the safety of workers.

[0025] 5. The device used in the grinding method of the present application has adjustable height and spacing of the matching pressing blocks, which adapts to the positioning of safety valve seats of multiple sizes and specifications, and is very convenient to install and disassemble, which can effectively reduce the labor intensity.

[0026] The following further description is made in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The structure schematic view of the device matched with Example 1;

[0028] Figure 2 The structure schematic view of the device matched with Example 2.

[0029] In the drawings, 1 is a turntable, 2 is an eccentric positioning disc, 3 is a mounting bracket, 4 is a grinding head, 5 is a mounting hole, 6 is a threaded hole, 7 is a mounting shaft, 8 is a circumferential positioning sleeve, 10 is a pressing block, 11 is a first pressing block, and 12 is a second pressing block. DETAILED DESCRIPTION

[0030] Example 1

[0031] Reference Figure 1The application relates to a device matched with a safety valve seat grinding method, which comprises a rotating disc, an eccentric positioning disc, a mounting support and a grinding head. A mounting hole is arranged in the center of the rotating disc, and a plurality of threaded holes are arranged on the top surface of the rotating disc; in the embodiment, the rotating disc is rotatably arranged on a platform and is driven to rotate by a power mechanism; the threaded holes are arranged in two groups, the number of the threaded holes in each group is multiple, and the threaded holes are uniformly distributed along the radial direction of the rotating disc. The upper portion of the eccentric positioning disc is in a circular truncated cone structure, the diameter of the bottom surface of the circular truncated cone structure is smaller than the diameter of the eccentric positioning disc, a mounting shaft is arranged on the bottom surface of the eccentric positioning disc and is eccentric to the center, generally, the eccentric distance of the mounting shaft from the center is 1 / 8-1 / 5 of the outer diameter of the sealing surface of the safety valve seat to be ground, and a counterweight is fixedly arranged on the eccentric positioning disc to ensure the stability of operation. The grinding head is assembled on the mounting support through a mounting rod and is circumferentially limited, and corresponds to the mounting hole 5 of the rotating disc; in the embodiment, the mounting support is in an inverted U-shaped structure, the mounting support in the inverted U-shaped structure is fixed on the platform through two vertical sections and is located on the two sides of the rotating disc, a circumferential positioning sleeve 8 is arranged on the horizontal section of the mounting support in the inverted U-shaped structure, the circumferential positioning sleeve 8 can adopt a square tube or a hexagonal tube, and in the embodiment, the circumferential positioning sleeve adopts a square tube, the mounting rod of the grinding head is assembled in the circumferential positioning sleeve to form circumferential limitation, and obviously, the cross section of the mounting rod of the grinding head is adapted to the cross section of the square tube or the hexagonal tube. The eccentric positioning disc is fixedly arranged on the rotating disc through the mounting shaft and is driven to eccentrically rotate by the rotating disc. The matched device is also matched with two pressing blocks 10, each pressing block comprises a first pressing block 11 and a second pressing block 12, the first pressing block is in an L shape, strip-shaped holes are arranged on the two folded edges of the first pressing block, the first pressing block is fixedly connected through screw threads penetrating through the horizontal folded edge and the threaded holes, the second pressing block is in an L shape, the vertical folded edge of the second pressing block is fixed on the vertical folded edge of the first pressing block through a bolt and can be adjusted in height, and the horizontal folded edge of the second pressing block is pressed on the connecting flange of the safety valve seat.

[0032] Example 2

[0033] Reference Figure 2 The difference between the embodiment and example 1 is that the whole eccentric positioning disc is in a circular truncated cone structure, in this case, the safety valve seat to be ground is supported on the rotating disc and is radially positioned through the through hole in the bottom and the eccentric positioning disc, so that the sealing surface of the safety valve seat to be ground faces upward.

[0034] Example 3

[0035] The safety valve seat is ground by using the device in example 1, the inner space of the safety valve seat is 50mm, the width of the sealing surface is 3mm, the eccentric distance of the mounting shaft is 8mm,

[0036] 1) the safety valve seat to be ground is supported on the eccentric positioning disc, and is radially positioned by the through hole in the bottom cooperating with the circular truncated cone structure, so that the sealing surface of the safety valve seat to be ground faces upward;

[0037] 2) two pressing blocks are respectively distributed on the two sides of the eccentric positioning disc, the first pressing block of each pressing block is fixedly connected by the horizontal folded edge threadedly cooperating with the threaded hole through the bolt, the vertical folded edge of the second pressing block is fixed on the vertical folded edge of the first pressing block through the bolt, and the height is adjustable, and after the horizontal folded edge of the second pressing block is pressed tightly on the connecting flange of the safety valve seat, the position is locked;

[0038] 3) the grinding head is pressed tightly on the sealing surface of the safety valve seat under the action of the self weight;

[0039] 4) the rotating disc rotates to drive the safety valve seat to perform eccentric motion, and the motion track of the safety valve seat is located in the projection range of the grinding head, until the grinding is completed.

[0040] When eccentric grinding, the actual grinding area of the grinding head is (36*36-17*17)*3.14=3161.98mm 2 , and if the concentric grinding area is (28*28-25*25)*3.14=499.26mm 2 , that is, the grinding area of eccentric grinding is 6.33 times that of concentric grinding.

Claims

1. A method of lapping a safety valve seat, characterised by: The following equipment includes steps: The device includes a rotating disc (1), an eccentric positioning disc (2), a mounting bracket (3), and a grinding head (4). The center of the rotating disc (1) is provided with a mounting hole (5), and the top surface of the rotating disc (1) is provided with a plurality of threaded holes (6). The bottom surface of the eccentric positioning disc (2) is provided with a mounting shaft (7), and the eccentric positioning disc (2) is eccentrically arranged, The grinding head (4) is assembled on the mounting bracket (3) through the mounting rod and is circumferentially limited. Corresponding to the mounting hole (5) of the rotating disc, the eccentric positioning disc (2) is fixedly arranged on the rotating disc (1) through the mounting shaft (7) and is driven by the rotating disc (1) to rotate eccentrically. 1) The safety valve seat to be ground is supported on the rotating disc, and the through hole at the bottom cooperates with the eccentric positioning disc to form radial positioning, so that the sealing surface of the safety valve seat to be ground faces upward; 2) One end of the pressing block (10) is threadedly connected with the threaded hole on the rotating disc through a screw rod to form fixation, and the other end is pressed against the connecting flange of the valve seat to fix the position of the safety valve seat; 3) The grinding head is pressed against the sealing surface of the safety valve seat under the action of its own weight; 4) The rotating disc rotates to drive the safety valve seat to move eccentrically, and the movement track of the safety valve seat is located within the projection range of the grinding head, until the grinding is completed.

2. The method of claim 1 wherein: The mounting bracket (3) has an inverted U-shaped structure. The mounting bracket with an inverted U-shaped structure is fixed on both sides of the rotating disc through two vertical sections and is located above the rotating disc. The horizontal section of the mounting bracket with an inverted U-shaped structure is provided with a circumferential positioning sleeve (8). The mounting rod of the grinding head is assembled in the circumferential positioning sleeve (8) to form circumferential limiting.

3. The method of claim 2 wherein: The circumferential positioning sleeve (8) is a rectangular tube or a hexagonal tube, and the cross section of the mounting rod of the grinding head is adapted to the cross section of the rectangular tube or the hexagonal tube.

4. The method of claim 1 wherein: The eccentric positioning disc (2) has a circular truncated cone structure.

5. The method of claim 1 wherein: The upper part of the eccentric positioning disc has a circular truncated cone structure, and the bottom surface of the circular truncated cone structure has a smaller diameter than the diameter of the eccentric positioning disc. In step 1), the safety valve seat to be ground is supported on the eccentric positioning disc, and the through hole at the bottom cooperates with the circular truncated cone structure at the upper part of the eccentric positioning disc to form radial positioning, so that the sealing surface of the safety valve seat to be ground faces upward.

6. The method of claim 1 wherein: A counterweight block is fixedly arranged on the eccentric positioning disc (2).

7. The method of claim 1 wherein: The eccentricity of the mounting shaft (7) deviating from the center is 1 / 8-1 / 5 of the outer diameter of the sealing surface of the safety valve seat to be ground.

8. The method of claim 1 wherein: The threaded holes are provided in two groups, and the number of threaded holes in each group is multiple. The threaded holes are uniformly and interval distributed along the radial direction of the rotating disc.

9. The method of claim 5 wherein: The number of the pressing blocks (10) is two. Each pressing block includes a first pressing block (11) and a second pressing block (12). The first pressing block has an L-shaped structure, and strip-shaped holes are arranged on both folded edges. The first pressing block is fixedly connected with the threaded hole through a bolt penetrating through the horizontal folded edge. The second pressing block has an L-shaped structure. The vertical folded edge of the second pressing block is fixedly connected with the vertical folded edge of the first pressing block through a bolt, and the horizontal folded edge is pressed against the connecting flange of the safety valve seat.

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