Blind plate structure for valve pressure test and pressure test device

Abstract

The utility model relates to the field of valve pressure testing equipment, in particular to a blind plate structure for a valve pressure test and a pressure testing device, which are simple in structure and low in cost, and can meet the use of valves with various specifications and sizes and the testing requirements of different pressures. Wherein the cylinder body and the piston adopt a multi-stage step structure, and can be suitable for pressure tests of valves of various specifications, and during pressure tests, only the piston of which the area of a valve port is smaller than that of the end part of the piston needs to be selected, so that the requirement of plugging the valve port can be met, and the valve cannot be damaged due to the overlarge diameter of the piston and the acting force of a medium; according to the utility model, the energy consumption of the oil cylinder can be greatly reduced, and the pressure test cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of valve pressure testing equipment, specifically a blind flange structure and pressure testing device for valve pressure testing. Background Technology

[0002] Currently, valve pressure testing devices are broadly classified into clamping type, top-pressure type, submersible type, and gripping type based on valve type, connection method, and other structural features. They are generally powered by hydraulic systems. Existing high-temperature and high-pressure systems in the power generation industry mostly use welded valves. Welded valves primarily employ top-pressure type pressure testing devices. During the pressure testing process, the clamping force of the hydraulic cylinder is used to forcibly seal both ends of the valve, and the blind flange structure is a single flat plate. In existing technology, different pressure testing devices are configured according to the valve specifications and pressure. However, as valve specifications and pressures expand, the cost of purchasing pressure testing devices increases significantly.

[0003] Furthermore, as the operating conditions of generator sets become increasingly demanding, such as supercritical and ultra-supercritical, valve pressure tests require greater tightening force. Therefore, how to reduce pressure testing costs and meet the pressure testing needs of valves of various specifications is an urgent problem to be solved. Utility Model Content

[0004] The purpose of this invention is to provide a blind flange structure and pressure testing device for valve pressure testing. The structure is simple and the cost is low. It can meet the needs of valves of various sizes and different pressure levels.

[0005] To solve the above technical problems, this utility model provides a blind plate structure for valve pressure testing, including a cylinder, a piston and a mandrel. The inner hole of the cylinder and the outer wall of the piston both adopt a multi-stage stepped structure and each step surface corresponds to the other. One end of the piston is disposed in the inner hole and there is an axial gap between its end and the inner hole. The other end extends out of the inner hole and fits against its outer wall.

[0006] The piston has a through hole, and the mandrel extends into the through hole through the inner hole. The mandrel has a medium channel for communicating with the valve port. The area of ​​the valve port is smaller than the area of ​​the end of the piston.

[0007] Furthermore, the piston has several sealing rings arranged from the outside to the inside on the side wall near the valve port.

[0008] Furthermore, a sealing ring 2 is provided between the circumferential stepped surface of the inner hole and the circumferential outer wall stepped surface of the piston.

[0009] Furthermore, the cylinder, the piston, and the spindle are arranged on the same axis.

[0010] Furthermore, the cylinder body has several sealing grooves on the side wall away from the valve port, and a sealing ring is provided in the sealing groove.

[0011] Furthermore, the cylinder body is provided with a second medium channel, which is connected to the axial clearance. A radial clearance is provided between the spindle and the through hole, which is connected to the axial clearance. A pipe joint is connected to the outside of the second medium channel.

[0012] Furthermore, the cylinder body is equipped with a lifting device.

[0013] Furthermore, the outer walls of the cylinder and the piston are provided with a plurality of limiting components, the limiting components including a first bolt, a second bolt and a limiting plate, the limiting plate having a waist-shaped groove, the first bolt and the second bolt passing through the waist-shaped groove and being fixedly connected to the cylinder and the piston respectively, and the first bolt and the second bolt slidingly engaging with the waist-shaped groove respectively.

[0014] This utility model also provides a pressure testing device, which is equipped with the above-mentioned blind plate structure for valve pressure testing. It further includes a bracket, a fixed baffle, a slide rail, a movable baffle, and a linear drive mechanism. The fixed baffle and the slide rail are respectively fixedly installed on the bracket. The movable baffle is opposite to the fixed baffle and slidably installed on the slide rail. The linear drive mechanism is fixedly installed on the bracket and its output end is fixedly connected to the outside of the movable baffle. The blind plate structure has two sets and is respectively fixedly installed on the fixed baffle and the movable baffle. The fixed baffle and the movable baffle are respectively provided with a medium inlet communicating with the medium channel of the two sets of blind plate structures.

[0015] Furthermore, the end of the mandrel away from the cylinder body has a flange that abuts against the cylinder body. The movable baffle and the fixed baffle each have a flange placement groove on their opposite sides. The shape of the flange matches the flange placement groove and is placed within the flange placement groove.

[0016] The beneficial effects of this utility model are:

[0017] 1. The blind flange structure of this utility model is simple in structure, reliable in sealing, and low in cost. It is suitable for the pressure testing needs of valves of various specifications, replacing the original flat blind flange structure. It is easy to use and also suitable for the use of various specifications of top-tightening pressure testing devices. Specifically, the cylinder and piston in the blind flange structure adopt a multi-stage stepped structure, which can be used for pressure testing of valves of various specifications. The piston with a valve port area smaller than the piston end area is selected, and then a sealing ring that matches the valve port is installed. Other steps can be left uninstalled. This can meet the need to seal the valve port without damaging the valve due to the medium force caused by the piston diameter being too large, thus improving the safety during the pressure testing process.

[0018] 2. The piston in this utility model has a through hole, and the spindle passes through the inner hole and extends into the through hole. This design makes it easier to install and disassemble the cylinder and piston, and improves operating efficiency.

[0019] 3. The design of medium channel one and medium channel two in this utility model enables the medium to enter the valve body cavity in two ways for pressure testing, which improves the diversity of the pressure testing process.

[0020] 4. The pressure testing device of this utility model is simple to operate and can reduce the cost of pressure testing. Specifically, the clamping force of the oil cylinder only plays a pre-tightening role at the beginning. As the pressure increases, because the pressure-bearing area of ​​the piston is larger than the valve port area, the piston expands outward and tends to bulge, pressing the valve port. Once the sealing ring is pushed by the pressure, it can seal the gap at the valve port. At this time, the oil pump can stop working, saving energy. Moreover, as the test pressure is higher, the sealing force is greater, ensuring the effect of no leakage at the valve end face. Attached Figure Description

[0021] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a blind flange structure for valve pressure testing according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the application structure of the pressure testing device according to an embodiment of the present invention;

[0024] In the diagram: 1-Cylinder body, 2-Piston, 3-Mandrel, 4-Sealing ring one, 5-Sealing ring two, 6-Sealing ring three, 7-Lifting device, 11-Medium channel two, 21-Through hole, 31-Medium channel one, 9-Limiting assembly, 91-First bolt, 92-Second bolt, 93-Limiting plate, 931-Oval groove, 12-Fixed baffle, 13-Bracket, 14-Slide rail, 15-Moving baffle, 16-Linear drive mechanism, 100-Radial clearance, 200-Axial clearance, 300-Valve port. Detailed Implementation

[0025] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] In one specific embodiment of this utility model, such as Figure 1 As shown, a blind plate structure for valve pressure testing includes a cylinder 1, a piston 2 and a spindle 3. The cylinder 1, piston 2 and spindle 3 are arranged coaxially. The inner hole of the cylinder 1 and the outer wall of the piston 2 both adopt a multi-stage stepped structure and each step surface corresponds to the other. One end of the piston 2 is set in the inner hole and there is an axial gap 100 between its end and the inner hole. The other end extends out of the inner hole and fits against its outer wall.

[0027] The piston 2 has a through hole 21 inside, and the spindle 3 extends into the through hole 21 through the inner hole. The spindle 3 has a medium channel 31 for communicating with the valve port 300. The area of ​​the valve port 300 is smaller than the area of ​​the end of the piston 2. Several sealing rings 4 are provided on the side wall of the piston 2 near the valve port 300 from the outside to the inside. This design ensures that one or more sealing rings 4 can seal the valve port 300 when the valve of any size is selected for pressure testing. In addition, a sealing ring 5 is provided between the circumferential stepped surface of the inner hole and the circumferential stepped surface of the outer wall of the piston 2, which improves the sealing effect between the two.

[0028] In practical applications, the test medium enters the through hole 21 and the test valve cavity through the medium channel 31 of the mandrel 3. As the pressure increases, because the area of ​​the valve port 300 is smaller than the area of ​​the end of the piston 2, the piston 3 expands outward and tends to bulge, pressing the valve port 300. The sealing ring 4 is pushed by the pressure, sealing the gap between it and the valve port 300, thus playing a sealing role. As the test pressure increases, the sealing force becomes greater, ensuring that there is no leakage at the valve port.

[0029] In this embodiment, the cylinder body 1 has several sealing grooves on the side wall away from the valve port 300, and a sealing ring 6 is provided in the sealing groove. This design can improve the sealing performance between the cylinder body 1 and the baffle in the application of the blind plate structure.

[0030] In this embodiment, sealing ring 4, sealing ring 5, and sealing ring 6 are all made of nitrile rubber O-rings, which provide reliable sealing and are not easily damaged.

[0031] In this embodiment, the cylinder body 1 is provided with a second medium channel 11, which is connected to the axial clearance 100. A radial clearance 200 is provided between the spindle 3 and the through hole 21, which is connected to the axial clearance 100. A pipe joint 8 is connected to the outside of the second medium channel 11. When the test medium is selected to enter the valve cavity from the first medium channel 31, the pipe joint 8 is in a blocked state. At this time, the test medium is gas, and no external medium enters the second medium channel 11. When the second medium channel 11 is selected as the test medium inlet, the first medium channel 31 is closed, and the test medium enters the axial clearance 100 and the radial clearance 200 from the second medium channel 11, and finally enters the valve cavity. At this time, the pipe joint 8 is connected to a pressure pump, and the test medium is water.

[0032] In this embodiment, the cylinder body 1 is provided with a lifting device 7, which can be used to lift the blind plate structure as a whole, making it convenient for transportation and installation.

[0033] In this embodiment, several limiting components 9 are provided on the outer side walls of the cylinder 1 and the piston 2. The limiting components 9 include a first bolt 91, a second bolt 92 and a limiting plate 93. The limiting plate 93 has a waist-shaped groove 931. The first bolt 91 and the second bolt 92 pass through the waist-shaped groove 931 and are threadedly connected to the cylinder 1 and the piston 2, respectively. The first bolt 91 and the second bolt 92 are slidably engaged with the waist-shaped groove 931. Through the design of the limiting plate and its waist-shaped groove, the movement distance of the piston protruding outward towards the valve port under pressure expansion can be limited, and the piston can play a certain guiding role during the movement process.

[0034] like Figure 2 As shown, a pressure testing device is equipped with a blind flange structure for valve pressure testing. It also includes a bracket 13, a fixed baffle 12, a slide rail 14, a movable baffle 15, and a linear drive mechanism 16. The fixed baffle 12 and slide rail 14 are fixedly mounted on the bracket 13. The movable baffle 15 is opposite to the fixed baffle 12 and slidably mounted on the slide rail 14. The linear drive mechanism 16 is fixedly mounted on the bracket 13, and its output end is fixedly connected to the outside of the movable baffle 15. The blind flange structure has two sets, which are respectively fixedly mounted on the fixed baffle 12 and the movable baffle 15. The fixed baffle 12 and the movable baffle 15 are respectively provided with a medium inlet communicating with the medium channel 31 of the two sets of blind flange structures. In this embodiment, the linear drive mechanism can be a hydraulic cylinder.

[0035] Specifically, the end of the spindle 3 away from the cylinder 1 has a flange that abuts against the cylinder 1. The movable baffle 15 and the fixed baffle 12 each have a flange placement groove on their opposite sides. The shape of the flange matches the flange placement groove and is placed in the flange placement groove.

[0036] In practical use, select an appropriate piston 2 step according to the size of the valve specification, and select a piston whose valve port 300 area is smaller than the piston 2 end area. That is, the pressure-bearing area of ​​piston 2 is always greater than the valve port 300 area, which can ensure that the valve port 300 is always in a sealed state, and at the same time avoid the valve body being damaged by the pressure of the test medium due to the piston area being too large.

[0037] Then, the flanges of the spindle 3 in the two sets of blind flange structures are fixed to the flange placement grooves on the fixed baffle 12 and the movable baffle 15 respectively. The valve to be tested is then hoisted between the two sets of blind flange structures. The cylinder is opened and the movable baffle 15 is moved on the slide rail 14, so that the pistons 2 in the two sets of blind flange structures are respectively in contact with the valve ports 300 on both sides. Then, the test medium enters the medium channel in the two sets of blind flange structures from the medium inlet on the fixed baffle and the movable baffle respectively, and then enters the valve port, i.e., the valve cavity. As the pressure increases, because the pressure-bearing area of ​​the piston 2 is greater than the area of ​​the valve port 300, the piston 2 expands outward and tends to bulge outward, pressing the valve port 300. The cylinder 1 is in close contact with the fixed baffle 12 and the movable baffle 15. The sealing ring 4 is pushed by the pressure, sealing the gap at the valve port 300, thus playing a sealing role.

[0038] When the test pressure exceeds the force of the hydraulic cylinder, the cylinder contracts, and the oil pressure automatically increases. Piston 2 protrudes significantly but remains tightly against the valve port 300, unaffected by the cylinder's contraction, until the specified test pressure value is reached, at which point the two remain in balance. The increase in oil pressure here is not due to the operation of the oil pump but to the test pressure itself, which saves energy consumption. Based on the YFB-600 test device's 7.5KW oil pump motor and a valve port diameter of 250mm, with each test lasting approximately 1 hour, the energy consumption is 7.5 kWh. At 1 yuan per kWh, this saves 7.5 yuan. For long-term and large-scale use, this can significantly reduce the cost of pressure testing.

[0039] The piston 2 of this invention has a larger pressure-bearing area than the valve port 300 area, which allows the oil cylinder to provide preload only initially, ensuring that the piston 2 fits the valve port 300. Then, during the test, as the pressure increases, the piston 2 expands outward and tends to bulge outward, naturally pressing the valve port 300. The sealing ring 4 is pushed by the pressure, sealing the gap at the valve port 300 and playing a sealing role. At this time, the tightening force of the oil cylinder is not required, so the oil pump is turned off, which can save energy and avoid noise generation.

[0040] The above-disclosed embodiment is merely a preferred embodiment of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A blind plate structure for valve pressure testing, characterized in that: It comprises a cylinder body (1), a piston (2) and a core shaft (3), wherein the inner hole of the cylinder body (1) and the outer wall of the piston (2) both adopt a multi-step structure and the respective step surfaces correspond to each other one by one, one end of the piston (2) is arranged in the inner hole and an axial gap (100) is provided between the end of the piston (2) and the inner hole, and the other end extends out of the inner hole and fits with the outer wall thereof; The piston (2) is provided with a through hole (21), the core shaft (3) passes through the inner hole and extends into the through hole (21), and the core shaft (3) is provided with a medium channel (31) for communicating with a valve port (300), and the area of ​​the valve port (300) is smaller than the area of ​​the end of the piston (2).

2. A blind plate structure for valve pressure testing according to claim 1, characterized in that: A plurality of sealing rings (4) are arranged on the side wall of the piston (2) close to the valve port (300) from the outside to the inside.

3. A blind plate structure for valve pressure testing according to claim 1, characterized in that: A second sealing ring (5) is provided between the circumferential step surface of the inner hole and the circumferential outer wall step surface of the piston (2).

4. A blind plate structure for valve pressure testing according to claim 1, characterized in that: The cylinder body (1), the piston (2) and the core shaft (3) are coaxially arranged.

5. A blind plate structure for valve pressure testing according to claim 1, characterized in that: A plurality of sealing grooves are provided on the side wall of the cylinder body (1) away from the valve port (300), and a sealing ring three (6) is provided in the sealing groove.

6. A blind plate structure for valve pressure testing according to claim 1, characterized in that: The cylinder body (1) is provided with a second medium channel (11), the second medium channel (11) is communicated with the axial gap (100), a radial gap (200) is provided between the core shaft (3) and the through hole (21), the radial gap (200) is communicated with the axial gap (100), and the outer side of the second medium channel (11) is connected with a pipe joint (8).

7. A blind plate structure for valve pressure testing according to claim 1, characterized in that: The cylinder body (1) is provided with a lifting device (7).

8. A blind plate structure for valve pressure testing according to claim 1, characterized in that: A plurality of limit assemblies (9) are provided on the outer side walls of the cylinder body (1) and the piston (2), and the limit assemblies (9) include a first bolt (91), a second bolt (92) and a limit plate (93), and a waist-shaped groove (931) is provided on the limit plate (93), and the first bolt (91) and the second bolt (92) respectively pass through the waist-shaped groove (931) to be fixedly connected to the cylinder body (1) and the piston (2), and the first bolt (91) and the second bolt (92) respectively slide in cooperation with the waist-shaped groove (931).

9. A pressure test device, equipped with a blind plate structure for valve pressure test according to any one of claims 1 to 8, characterized in that: The invention also comprises a bracket (13), a fixed baffle (12), a slide rail (14), a movable baffle (15) and a linear drive mechanism (16); the fixed baffle (12) and the slide rail (14) are respectively fixedly mounted on the bracket (13); the movable baffle (15) is arranged opposite to the fixed baffle (12) and is slidably mounted on the slide rail (14); the linear drive mechanism (16) is fixedly mounted on the bracket (13) and an output end is fixedly connected to the outer side of the movable baffle (15); the blind plate structure has two groups and is respectively fixedly mounted on the fixed baffle (12) and the movable baffle (15); the fixed baffle (12) and the movable baffle (15) are respectively provided with a medium inlet communicating with a medium channel 1 (31) of the two groups of the blind plate structures.

10. A pressure test device according to claim 9, characterized in that: The end of the core shaft (3) away from the cylinder body (1) has a flange, and the flange abuts against the cylinder body (1). The movable baffle (15) and the fixed baffle (12) have flange placement grooves on opposite sides respectively. The shape of the flange matches the flange placement groove and is placed in the flange placement groove.

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