CN112254896B - A performance testing device and testing method for a packing sealing system for quarter-turn valve stems - Google Patents

Abstract

The invention belongs to the technical field of valve stem packing seal testing, and specifically relates to a performance testing device and testing method of a packing sealing system for angular stroke valve stems applied to a valve stem packing seal testing system. The invention includes a test bench and a tested component fixed on the test bench; the tested component includes a stuffing box, a packing and a valve stem that are coaxially sleeved from outside to inside. The characteristic is that the invention also includes a medium input system. , packing ballast system, drive system and data acquisition components. The invention has the advantages of convenient and reliable use, simple and fast operation and high degree of automation, and can ensure the accuracy and comprehensiveness of the performance test data of the valve stem packing seal testing system.

Description

A performance testing device and testing method for a packing sealing system for quarter-turn valve stems

Technical field

The invention belongs to the technical field of valve stem packing seal testing, and specifically relates to a performance testing device and testing method of a packing sealing system for a angular stroke valve stem used in a valve stem packing seal testing system.

Background technique

At present, the valve stem sealing methods in the process industry mainly include packing seals and bellows seals. Among them, packing seals are more widely used because of their low friction, good sealing performance and long service life. In the packing seal structure, the stuffing box needs to be filled with packing, and a load is applied to the packing gland to compress the packing. At this time, the packing is radially deformed by the axial force, thereby generating radial contact pressure with the valve stem, and finally Achieve the purpose of preventing the leakage of the medium inside the valve. When designing a valve body with a packing seal structure, an important step is to reasonably determine the packing combination type, the packing pressure, and even the friction on the valve stem when the packing is tightened. These all need to be passed in advance. Conduct comprehensive performance tests on the valve stem packing sealing system to obtain test data, and perform subsequent calculations based on the obtained test data. The traditional valve stem packing seal testing system has a low degree of automation. The application of load is simply obtained by manually changing the pressure of the packing gland. On the one hand, the pressure is determined purely by experience, which makes it difficult to ensure the accuracy of the test data; on the other hand, It is also impossible to obtain continuous change data of pressure in the packing area online, making the test less flexible and the comprehensiveness of the test data also insufficient. In addition, low automation often brings repetitive labor, making the entire testing process highly labor-intensive and low in operating efficiency. It is difficult to meet the current fast-paced and high-efficiency automated testing needs.

Contents of the invention

One of the purposes of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a structurally reasonable and practical performance testing device for a packing seal system for a quarter-turn valve stem, which has the advantages of convenient and reliable use, easy and fast operation, and a high degree of automation. , can ensure the accuracy and comprehensiveness of the performance test data of the valve stem packing seal test system; another purpose of the present invention is to provide a test method based on the above device, so as to realize its actual test steps in a concrete and concise manner.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A performance testing device for a packing sealing system for angular stroke valve stems, including a test bench and a tested component fixed on the test bench; the tested component includes a stuffing box, packing and valve coaxially sleeved from outside to inside Rod, characterized in that the device also includes:

Medium input system: includes a medium input component for inputting medium into the pressure chamber of the pressure kettle and a medium heating component for heating the medium; the top of the pressure kettle is sealed against the bottom end face of the stuffing box, so that Ensure that the medium enters the stuffing box cavity from the pressure-bearing cavity;

Packing ballast system: including a linear hydraulic actuator that can apply dynamic or static axial load to the packing gland at the top of the stuffing box. The linear hydraulic actuator provides hydraulic pressure through a hydraulic ballast assembly;

Driving system: used to drive the valve stem to rotate around the axis of the stuffing box in the stuffing box cavity;

Data acquisition component: used to achieve online acquisition of information and data at each monitoring point, including the medium pressure gauge or medium pressure sensor used to obtain the medium input pressure at the medium input component, and the medium temperature used to obtain the medium temperature in the pressure chamber Sensors, hydraulic pressure gauges or hydraulic pressure sensors used to obtain the hydraulic pressure at the packing ballast system, torque sensors used to obtain the torque of the drive system on the valve stem, position sensors used to obtain the current rotational position of the valve stem, and for monitoring the packing Leak monitor for medium leakage at the top of the seal.

Preferably, the shape of the stuffing box is an integrated cylindrical structure formed by a combination of a valve cover and a valve housing, with the valve cover end of the stuffing box being located at the bottom end of the stuffing box; the device also includes a valve sandwiched at the bottom end of the stuffing box. The adapter plate serves as a transitional connection between the pressure kettle and the pressure kettle. The pressure-bearing cavity of the pressure kettle, the cavity of the adapter plate and the cavity of the stuffing box are all coaxially arranged.

Preferably, the medium heating component includes a heater located around the periphery of the pressure kettle; a pressure relief pipeline connected to the pressure chamber is also arranged at the bottom end of the pressure kettle, and the pressure relief pipeline is controlled to start by a pressure relief valve. close.

Preferably, the medium input component includes a medium pressure source, a medium cut-off valve, a booster, a regulating valve, a medium check valve and a safety valve arranged sequentially on the medium pipeline along the direction of medium flow; the medium check valve The conduction direction is the direction of medium flow, and a buffer tank is arranged between the regulating valve and the supercharger; the medium pressure gauge includes a first medium pressure gauge and a second medium pressure gauge, and the first medium pressure gauge is arranged at the medium pressure On a section of the medium pipeline between the source and the medium cut-off valve, the second medium pressure gauge is arranged on a section of the medium pipeline between the medium check valve and the medium pressure gauge.

Preferably, the packing ballast system includes a tank for containing hydraulic oil. After the hydraulic oil in the tank is pumped out by a hydraulic pump, it passes through a hydraulic pressure reducing valve, an accumulator, a hydraulic one-way valve, and a pressure control valve in sequence. Enter the P port of the hydraulic directional valve, the T port of the hydraulic directional valve is directly connected to the tank, and the A and B ports of the hydraulic directional valve are connected to the first chamber and the second chamber of the linear hydraulic actuator through a hydraulic circuit respectively. room; each hydraulic circuit is equipped with a hydraulic cut-off valve and a hydraulic pressure gauge or hydraulic pressure sensor.

Preferably, the linear hydraulic actuator includes an outer shell and a piston rod that penetrates the outer shell and can make reciprocating linear motion along the axial direction of the outer shell, with one end of the piston rod used to cooperate with the packing gland as the working end, and the The linear hydraulic actuator also includes a second piston that can push the piston rod to produce an axial linear motion in the direction of the working end, and a coaxial piston that is sleeved on the piston rod and can make a reciprocating sliding motion in the axial direction of the piston rod. The first piston; the inner cavity wall of the outer shell and the outer wall of the piston rod are enclosed to form a sleeve-shaped chamber. The first piston and the second piston divide the chamber into a space between the first piston and the upper shell cover. a first chamber between the first piston and the second piston, and a third chamber between the second piston and the lower shell cover, and the first chamber, the second chamber The chamber and the third chamber are independent of each other, and the third chamber is connected to the air pressure source or the atmospheric environment through the second gas reversing valve; the first piston and the second piston are arranged with an elastic direction parallel to the piston rod axis and coaxially sleeved An elastic member is provided at the outer wall of the piston rod. The elastic member is a spring, and the two ends of the elastic member extend axially and fix the first piston and the second piston respectively.

Preferably, the piston rod shaft located in the third chamber is coaxially provided with an annular step, and the bottom surface of the second piston and the upper shoulder of the annular step form a stop fit that limits the downward movement of the second piston; The bottom end of the rod forms the working end.

Preferably, the driving system includes a gas pressure reducing valve connected to the gas source. The P port and the T port of the first gas reversing valve are respectively connected to the outlet end of the gas pressure reducing valve and the external atmospheric environment. Port A and port B are respectively connected to the air intake chamber and return chamber of the pneumatic actuator through a gas circuit; a set of speed control valves are arranged on each gas circuit; the piston rod is a sleeve, and the connecting rod is coaxial It penetrates into the shaft sleeve and is coaxially fixed with the valve stem; the top end of the connecting rod is coaxial with the transition rod and the adjacent ends of the two are connected to each other through the torque sensor; a pneumatic device that can realize rotation within a specified angle range The power output shaft of the actuator is sleeve-shaped and extends vertically upward to form a first connecting flange. After the transition rod passes coaxially through the power output shaft, a second connection is arranged at the top of the transition rod. Flange; the drive system also includes an electric actuator that can achieve continuous rotation. The power shaft of the electric actuator extends vertically downward and a third connecting flange is arranged at the bottom end; the first connecting flange , the second connecting flange and the third connecting flange are coaxial with each other, and the second connecting flange selects one of the first connecting flange and the third connecting flange for flange matching.

Preferably, the test bench has a three-layer frame structure, the lower frame constitutes a base that can be rested on the base surface, the middle frame is used to fix the pressure kettle, and the upper frame is used to fix the pneumatic actuator and linear hydraulic actuator; the upper layer Vertical movement toward and away from each other can occur between the frame and the middle frame.

Preferably, a test method using the performance test device of a packing seal system for a quarter-turn valve stem is characterized in that it includes the following steps:

A0). According to the specifications and dimensions of the component under test, adjust the test bench to a suitable height, and assemble the component under test through the adapter plate and the middle frame of the test bench; if the component under test is a continuous rotation type, assemble it through the transition The rod connects the electric actuator and the valve stem, and locks the position of the test bench; if the component under test is a partial rotation type, connects the pneumatic actuator and the valve stem through the transition rod, and locks the position of the test bench;

A1), start the hydraulic pump, according to the ballast demand of the packing, control the hydraulic reversing valve to supply pressure to the designated chamber of the linear hydraulic actuator, adjust the pressure control valve to slowly pressurize the corresponding chamber of the linear hydraulic actuator ; When the hydraulic pressure in the first or second chamber of the linear hydraulic actuator increases to the specified pressure PA1, the hydraulic circuit is closed and cut off, and the linear hydraulic actuator is synchronously monitored and recorded through a hydraulic pressure gauge or hydraulic pressure sensor. Changes in internal pressure values;

A2), start the supercharger and heater, and jointly control the supercharger, heater and pressure relief valve to make the pressure chamber load stable and balanced to the specified temperature T and pressure PB1, and synchronize through the medium pressure gauge and medium temperature sensor Monitor and record changes in temperature and pressure values in the pressure chamber;

A3) Use the leakage monitor to monitor whether excessive leakage occurs at the packing seal; if not, proceed to step A4. If so, depressurize the pressure chamber, gradually increase the hydraulic pressure to PA2 again, and confirm that the hydraulic circuit and gas are closed. loop, re-execute steps A2~A3 in sequence;

A4). Start the drive module. If the component under test is of partial rotation type, adjust the speed control valve so that the rotation speed V of the pneumatic actuator meets the test requirements. By controlling the action of the first gas reversing valve, the pneumatic actuator moves at a predetermined angle. Rotate back and forth several times, and simultaneously monitor and record the changes in the number of reciprocations, torque values, and angular displacement speed of the valve stem through the torque sensor and position sensor; if the component being tested is a continuous rotation type, the rotation speed V of the electric actuator meets According to the test requirements, the torque sensor and position sensor are used to simultaneously monitor and record the changes in the torque value, rotation number and rotation speed value of the valve stem;

A5) Use the leakage monitor again to monitor whether excessive leakage occurs at the packing seal; if not, proceed to step A6. If so, depressurize the pressure chamber and gradually increase the hydraulic pressure to PA3 again, confirm that the hydraulic circuit is closed and For gas circuit, repeat steps A2~A5;

A6), the pneumatic actuator or electric actuator continues to drive the valve stem to rotate, and the leakage monitor is used to monitor in real time whether excessive leakage occurs at the packing seal, and the changes in various index values are synchronously monitored and recorded, including but not limited to: The pressure value of the first chamber or the second chamber of the linear hydraulic actuator, the pressure value and temperature value of the pressure-bearing chamber, the torque value of the valve stem, the angular displacement speed or rotation speed, the number of reciprocations or the number of rotations; until the packing If excessive leakage occurs at the seal, stop the pneumatic actuator or electric actuator, release the pressure in the pressure chamber, then gradually increase the hydraulic pressure to PA4, confirm that the hydraulic circuit and gas circuit are closed, and repeat steps A2 to A5;

A7). Organize various index values and obtain test data.

The beneficial effects of the present invention are:

1. The present invention can provide comprehensive and comprehensive test monitoring of various performance parameters for the performance test of the angular stroke valve stem packing sealing system, and can conduct more scientific research on the influence of the performance of the valve stem packing sealing system under different conditions, and conduct performance evaluation accordingly. evaluate.

2. The tested components required by this invention should include valve covers (the valve stem packing sealing system of most valves is composed of valve covers, packing combinations, valve stems, packing pressure sleeves, etc.); the valve cover is also included in the tested components. The component can more closely approximate the actual working state of the valve stem packing seal system. By applying medium load to the pressure chamber and conducting several performance tests, it can guide design practice more effectively. Even during daily testing, you can directly select the corresponding parts of the product: valve cover packing, etc. to form the component under test for testing. There is no need to make additional corresponding test pieces, which not only saves test processing costs, but also maximizes the simulation of real-life usage conditions. , and the accuracy of test data can be significantly improved. In addition, the test bench also adopts a multi-layer frame structure, which is more conducive to the use of different types of stuffing boxes; by raising and lowering the upper frame of the test bench relative to the lower frame, it can cover the bonnet structure of most valves, and test Expansion capabilities can also be effectively guaranteed.

3. In order to obtain the optimal ballast force, pre-tightening load and changing rules of the packing, the present invention provides a packing ballast system. The packing ballast system is mainly realized through a hydraulic structure, and by monitoring the pressure value of the linear hydraulic actuator, the changes in the packing ballast force can be obtained, which solves the problems of the small position of the packing and the inconvenience of directly arranging the force sensor. Moreover, it has a high degree of automation, is more convenient to operate, and greatly reduces human labor intensity.

4. In the packing ballast system, the present invention abandons the traditional adjustment pressure structure that relies solely on experience, which is inconvenient and inefficient, and instead utilizes the traditional linear hydraulic actuator structure to ensure that the valve stem Reliable and continuously controllable load application requirements on the packing area during testing of packing seal testing systems. More importantly, because the filler is an elastomer, it is very easy to cause stress relaxation during long-term high-load tests and even actual operations. Due to the almost incompressibility of hydraulic pressure, the external hydraulic ballast components will collapse once compressed. Loading causes the filler to be under constant pressure, which will obviously lead to a discrepancy between the ideal ballast force and the actual ballast force, which will lead to deviations in the test data. Therefore, when conducting experimental operations, testers definitely hope to conduct a full range of simulations to maximize the reproduction of the real environment. The present invention designs two sets of pistons and cooperates with elastic parts with axial elasticity such as springs and elastic colloid layers located between the two sets of pistons. On the one hand, it can simulate the stress relaxation conditions of the filler in both tests and real environments. On the other hand, it can also simulate the real environment with dynamic load characteristics in which traditional packing sealing ends use disc springs, etc., thus providing a basic guarantee for the comprehensiveness of the final test data.

5. As a further preferred solution of the above solution, the second piston can be integrally fixed directly on the piston rod, or can be embedded in the piston rod axially by injecting an annular groove. The present invention preferably adopts a one-way limiting structure formed by an annular step, so as to achieve the purpose of synchronous downward movement of the second piston and the piston rod by limiting the downward movement of the second piston. Of course, a stroke limiter should be provided between the first piston and the second piston to prevent the elastic member from being over-compressed.

6. Considering that when the piston rod makes axial reciprocating motion relative to the outer shell, there must be dynamic and static parts that match the outer shell and even the corresponding piston. Therefore, sealing rings need to be arranged to strengthen the matching gaps between them to ensure the sealing effect. For the outer shell, since it is formed by the cooperation of the cylinder body, the upper shell cover and the lower shell cover, a sealing ring needs to be arranged at the mounting hole. For each piston, a sealing ring needs to be arranged between each piston and the corresponding mating part. Seals.

7. During actual operation, the piston rod can be a solid rod body or a hollow bushing as described in the present invention. The advantage of the hollow bushing is that the valve stem can directly pass through the barrel cavity of the bushing coaxially, and the power component that drives the valve stem can be arranged directly above the present invention, thereby being connected to the test area located directly below the present invention. Completely separated; in this way, larger power components are completely independent from the test area, making installation more convenient. The test area where the component under test is located can also have more space to accommodate other sensing components, and the layout is also easier. More flexible.

8. The driving technical solution adopted in this invention covers the driving requirements of the valve stem to the greatest extent according to the working requirements of different types of valves on the market. For valve stems with different rotation types, in order to maximize the simulation reality effect, the present invention uses two sets of driving sources, a pneumatic actuator and an electric actuator, to correspond to the two types of valve stems, thereby achieving high speed, medium speed, and low speed. While waiting for different valve stem rotation speed movement requirements, it can also realize the selective use of pneumatic actuators and electric actuators through the selective cooperation of different connecting flanges, and ultimately facilitate the inspection of the valve stem rotation action on the valve stem packing sealing system. The purpose of the performance is influenced by the law, and the operation flexibility is extremely high.

Description of drawings

Figure 1 is a schematic structural diagram of the present invention;

Figure 2 is a diagram of the coordination state of the component under test and the test bench;

Figure 3 is a schematic structural diagram of a linear hydraulic actuator.

The actual correspondence between each label and component name in the present invention is as follows:

10-Test bench 11-Lower frame 12-Middle frame 13-Upper frame

20-Tested component 21-Stuffing box 21a-Valve cover 22-Valve stem

31-Pressure kettle 31a-pressure chamber 32-heater 33-pressure relief valve

34-medium pressure source 35-medium shut-off valve 36-supercharger

37-Regulating valve 37a-Buffer tank 38-Media check valve 39-Safety valve

41-Linear hydraulic actuator a-first chamber b-second chamber

41a-outer shell 41b-piston rod 41c-first piston

41d-Second piston 41e-Elastic member 41f-Annular step

41g-cylinder 41h-upper shell cover 41i-lower shell cover 41j-second gas reversing valve

42-Oil tank 43-Hydraulic pump 44-Hydraulic pressure reducing valve

45-Accumulator 46-Hydraulic check valve 47-Pressure control valve

48-Hydraulic reversing valve 49-Hydraulic shut-off valve

51-Medium pressure gauge 52-Medium temperature sensor 53-Hydraulic pressure gauge

54-Torque sensor 55-Position sensor 56-Leak monitor

60-Transfer plate

71-Gas source 72-Gas pressure reducing valve 73-First gas reversing valve 74-Speed regulating valve

75-Pneumatic actuator 75a-Connecting rod 75b-Transition rod

75c-Second connecting flange 75d-First connecting flange

76-Electric actuator 76a-Third connecting flange

Detailed ways

For ease of understanding, the specific structure and working mode of the present invention are further described below in conjunction with one of the application environments of the present invention:

The specific working structure of the present invention is shown in Figures 1-3. Its main structure includes a test bench 10 for fixing the component under test 20, a medium input system for providing medium and heating medium, and a filling system for filling the component under test. A packing ballast system that applies load, a driving system that drives the valve stem 22 to produce a circumferential rotation, and a data acquisition component that monitors and records corresponding data. in:

1. Test bench 10

The test bench 10 includes a three-layer frame structure, that is, it includes a lower frame 11 , a middle frame 12 and an upper frame 13 . The pressure kettle 31 of the medium input system is fixed on the middle frame 12 as shown in Figure 1-2, and is overall arranged in the area between the middle frame 12 and the lower frame 11. The component under test 20 is threaded and sealed at the top of the pressure kettle 31 through different adapter plates 60 depending on the model. At this time, the component under test 20 is located on the upper frame 13 as shown in Figure 1-2. In the area between the middle frame 12 and the middle frame 12; through the downward force of the piston rod 41b of the linear hydraulic actuator 41, the packing gland at the component under test 20 begins to apply ballast force to the packing.

During actual assembly, the lower frame 11 is directly placed on a base surface such as the ground. The lower frame 11 and the middle frame 12 are directly rigidly connected through support rods. The middle frame 12 and the upper frame 13 can be connected through telescopic rods or guide rails. They can directly realize the movement toward and away from each other, or they can also be directly used with the lifting motor to realize automated lifting operations. This is a routine operation, so there is no need to go into details.

2. Media input system

The media input system consists of two parts, namely the media input component and the media heating component.

The medium input component is shown in Figure 1-2, including a medium pressure source 34, a medium cut-off valve 35, a booster 36, a regulating valve 37, a medium check valve 38 and a safety device arranged sequentially on the medium pipeline along the direction of medium flow. Valve 39. The conduction direction of the medium one-way valve 38 is the direction of medium flow, and deleting this structure will not affect the actual working state of the present invention too much. A buffer tank 37a is arranged between the regulating valve 37 and the supercharger 36. The medium pressure gauge 51 includes a first medium pressure gauge and a second medium pressure gauge. The first medium pressure gauge is arranged on a section of the medium pipeline between the medium pressure source 34 and the medium cut-off valve 35 . The second medium pressure gauge is arranged on A section of the medium pipeline between the medium check valve 38 and the medium pressure gauge 51. The medium heating component includes a heater 32 located around the periphery of the pressure kettle 31 . A pressure relief pipeline connected to the pressure chamber 31a is also arranged at the bottom end of the pressure kettle 31. The pressure relief pipeline is controlled to open and close through the pressure relief valve 33.

During actual operation, the supercharger 36 pressurizes the medium pressure source 34 to a certain pressure and sends it to the pressure-bearing chamber 31a through the medium one-way valve 38. The heater 32 partially heats the pressure chamber 31a to heat the medium to a designated temperature. At the same time, the medium is also pressurized to a designated pressure under the dual loading of the supercharger 36 and the heater 32 .

3. Filling ballast system

As shown in Figure 1-2, the packing ballast system at least includes the oil tank 42, which is the hydraulic oil source, the hydraulic pump 43, the hydraulic pressure reducing valve 44, the accumulator 45, the hydraulic one-way valve 46, the pressure control valve 47, the hydraulic Directional valve 48, hydraulic shut-off valve 49 and linear hydraulic actuator 41. The linear hydraulic actuator 41 includes an outer housing 41a, a first piston 41c, a second piston 41d, an elastic member 41e and a piston rod 41b. As shown in Figure 3, during actual installation, the assembly of the cylinder 41g and the upper housing cover 41h can be completed first, and then the first piston 41c, the elastic member 41e, the second piston 41d and the piston rod 41b are installed respectively. The parts that need to be sealed can rely on sealing rings to ensure reliable sealing of moving parts and static parts.

The entire linear hydraulic actuator 41 is fixedly installed with the upper frame 13 . The first chamber a and the second chamber b need to be connected to the oil tank 42 as shown in Figure 1 through a special hydraulic circuit, while the third chamber is connected to the atmospheric environment or air pressure source as shown in Figure 1 through a pneumatic circuit. During the actual layout, special attention should be paid to the connection point between the second chamber b and the hydraulic circuit, that is, the layout position of the hydraulic circuit interface in the second chamber b, which needs to be designed as appropriate to avoid the occurrence of the first piston 41c and the second piston 41d. The hydraulic circuit interface is accidentally blocked due to excessive stroke. In addition, during actual design, an appropriate stroke limit can also be set between the first piston 41c and the second piston 41d, which can avoid excessive compression of the elastic member between the first piston 41c and the second piston 41d, and also prevent the elastic member between the first piston 41c and the second piston 41d. It can be ensured that when the two pistons run synchronously to the upper limit limit or the lower limit limit, the hydraulic circuit interface of the second chamber b is still located between the first piston 41c and the second piston 41d.

As can be seen in Figure 3: the first piston 41c and the piston rod 41b cooperate coaxially, the first piston 41c can slide arbitrarily along the axial direction of the piston rod 41b, and an elastic member is provided between the first piston 41c and the second piston 41d. The spring 41e, the second piston 41d and the piston rod 41b are coaxially matched and rely on the annular step 41f to form a one-way limited stop fit. In actual design, the piston rod 41b has a hollow sleeve structure, and the valve rod 22 and the connecting rod 75a in the component under test 20 can pass through the barrel cavity of the piston rod 41b to produce axial reciprocating motion. The bottom end of the piston rod 41b is in contact with the packing gland or pressure ring in the component under test 20 to ensure the load application effect on the packing in the stuffing box 21 of the component under test 20 .

During actual operation, the packing ballast system pressurizes and outputs hydraulic oil through the hydraulic pump 43, reduces the pressure through the hydraulic pressure reducing valve 44 and inputs it into the accumulator 45. The pressure control valve 47 regulates the hydraulic oil to the specified pressure, and through the hydraulic reversing valve 48 is output to the first chamber or the second chamber of the linear hydraulic actuator 41. When the linear hydraulic actuator 41 operates, the second gas reversing valve 41j operates to switch the third chamber to the venting state.

Under ideal test conditions without preload: when packing ballast is applied, hydraulic oil is output to the second chamber of the linear hydraulic actuator 41 through the hydraulic reversing valve 48. Under the action of hydraulic oil force, the first piston 41c abuts the upper shell cover 41h of the outer shell 41a, and the second piston 41d drives the piston rod 41b to apply hydraulic oil force to the packing gland.

Under realistic environment simulation test conditions with preload load: when packing ballast is applied, the hydraulic oil is output to the first chamber of the linear hydraulic actuator 41 through the hydraulic reversing valve 48. Under the action of the hydraulic oil force, the The first piston 41c transmits the hydraulic oil force to the second piston 41d through the elastic member 41e, that is, the spring, and the second piston 41d drives the piston rod 41b to apply the hydraulic oil force to the packing gland. Due to the existence of the elastic member 41e, a dynamic and compensated floating pressure effect that simulates real working conditions can be achieved.

When a test needs to be completed and the test piece needs to be replaced, the third chamber can be switched to the ventilation state by controlling the action of the second gas reversing valve 41j, and the piston rod 41b moves to the retracted state; when it is necessary to re-ballast the packing, etc. When the test piece is being tested, the third chamber can be switched to the venting state again through the operation of the second gas switching valve 41j.

4. Drive system

The drive system includes two sets of drive sources, which are a pneumatic drive source that can achieve a specified angular range of rotation for the valve stem 22 and an electric drive source that can achieve continuous rotation of the valve stem 22 .

When the component under test is of the partial rotation type, a pneumatic drive source can be used. The pneumatic driving source includes a gas source 71 , a gas pressure reducing valve 72 , a first gas reversing valve 73 , a speed regulating valve 74 and a pneumatic actuator 75 . The gas source 71 outputs gas of a certain pressure, and reduces it to a specified pressure through the gas pressure reducing valve 72 , and then passes through the first gas reversing valve 73 and the speed regulating valve 74 in order to output the gas to the corresponding chamber of the pneumatic actuator 75 . When the first gas reversing valve 73 switches, the flange connection between the first connecting flange 75d and the second connecting flange 75c can be realized as shown in Figure 2, thereby realizing the connection between the transition rod 75b and the pneumatic actuator 75. The torque transmission effect of stem 75a and thus valve stem 22. When the speed regulating valve 74 is working, online control of the reciprocating rotation speed of the valve stem 22 can be achieved.

When an electric drive source is used, the component under test is obviously a continuous rotation type. At this time, it is necessary to ensure that the first connecting flange 75d and the second connecting flange 75c are disconnected from each other, and the second connecting flange 75c and the third connecting flange 76a are connected, so as to realize the electric actuator 76, the connecting rod 75a and even Torque transmission effect of valve stem 22. The rotation speed of the electric actuator 76 can be adjusted through its own frequency conversion.

5. Data acquisition component

The data acquisition component is used to achieve online acquisition of information and data at each monitoring point, including a medium pressure gauge 51 or a medium pressure sensor used to obtain the medium input pressure at the medium input component, and a medium used to obtain the medium temperature in the pressure chamber 31a Temperature sensor 52, a hydraulic pressure gauge 53 or a hydraulic pressure sensor used to obtain the hydraulic pressure at the packing ballast system, a torque sensor 54 used to obtain the torque of the drive system on the valve stem 22, and a position used to obtain the current rotation position of the valve stem 22 The sensor 55 and the leakage monitor 56 are used to monitor the medium leakage condition at the top opening of the stuffing box 21 .

On the basis of the above structure, the test method of the present invention includes the following steps:

A0), according to the specifications and dimensions of the component under test 20, adjust the test bench 10 to a suitable height, and assemble the component under test 20 through the adapter plate 60 and the middle frame 12 of the test bench 10; if the component under test 20 is If the continuous rotation type is used, the electric actuator 76 and the valve stem 22 are connected through the transition rod 75b, and the position of the test bench 10 is locked; if the component under test 20 is of the partial rotation type, the pneumatic actuator 75 and the valve stem 22 are connected through the transition rod 75b. Valve stem 22, and complete the locking of the 10 position of the test bench;

A1), start the hydraulic pump 43, according to the ballast demand of the packing, control the hydraulic reversing valve 48 to supply pressure to the designated chamber of the linear hydraulic actuator 41, and adjust the pressure control valve 47 to make the linear hydraulic actuator 41 respond accordingly. The chamber is slowly pressurized; when the hydraulic pressure in the first chamber or the second chamber of the linear hydraulic actuator 41 increases to the specified pressure PA1, the hydraulic circuit is closed and cut off, and is monitored synchronously through the hydraulic pressure gauge 53 or the hydraulic pressure sensor. and record changes in the pressure value within the linear hydraulic actuator 41;

A2), start the supercharger 36 and the heater 32, and jointly control the supercharger 36, the heater 32 and the pressure relief valve 33 so that the pressure chamber 31a is loaded stably and balanced to the specified temperature T and pressure PB1, and through the medium pressure The table 51 and the medium temperature sensor 52 simultaneously monitor and record the changes in temperature and pressure values in the pressure chamber 31a;

A3) Use the leakage monitor 56 to monitor whether excessive leakage occurs at the packing seal; if not, proceed to step A4. If yes, depressurize the pressure chamber 31a, gradually increase the hydraulic pressure to PA2 again, and confirm that the hydraulic circuit is closed. and gas circuit, re-execute steps A2~A3 in sequence;

A4). Start the drive module. If the component under test is of partial rotation type, adjust the speed regulating valve 74 so that the rotation speed V of the pneumatic actuator 75 meets the test requirements. By controlling the action of the first gas reversing valve 73, the pneumatic actuator 75 rotates back and forth several times at a predetermined angle, and simultaneously monitors and records the changes in the valve stem torque value and angular displacement speed through the torque sensor 54 and the position sensor 55; if the component under test is a continuous rotation type, the electric actuator 76 is The rotation speed V meets the test requirements, and the changes in the torque value, rotation number, and rotation speed value of the valve stem are synchronously monitored and recorded through the torque sensor 54 and the position sensor 55;

A5), again monitor whether excessive leakage occurs at the packing seal through the leakage monitor 56; if not, proceed to step A6, if so, depressurize the pressure chamber 31a, and gradually increase the hydraulic pressure to PA3 again, confirm that the hydraulic pressure is turned off circuit and gas circuit, repeat steps A2~A5;

A6), the pneumatic actuator 75 or the electric actuator 76 continues to drive the valve stem 22 to rotate, and the leakage monitor 56 monitors whether excessive leakage occurs at the packing seal in real time, and simultaneously monitors and records the changes in various index values, including But it is not limited to: the pressure value of the first chamber or the second chamber of the linear hydraulic actuator 41, the pressure value and temperature value of the pressure-bearing chamber 31a, the torque value of the valve stem 22, the angular displacement speed or rotation speed, and the number of reciprocations. Or the number of turns; until excessive leakage occurs at the packing seal, stop the pneumatic actuator 75 or the electric actuator 76, release the pressure in the pressure chamber 31a, and then gradually increase the hydraulic pressure to PA4, confirm that the hydraulic circuit and gas circuit are closed, and repeat Steps A2~A5;

A7). Organize various index values and obtain test data.

Of course, the above is one of the specific embodiments of the present invention. In actual operation, the upper frame 13 and the middle frame 12 can be replaced by a lifting motor to drive the guide rail to realize mutual movement, or a telescopic rod with telescopic adjustment and position fixing functions. The heating method of the heater 32 can also be used. Other known heating processes are used to achieve this, and even corresponding components on each system are added or deleted to increase functions or weaken or reduce functions, etc. Such conventional structural changes based on the known structure of the present invention should be treated as Equivalent or similar designs fall within the protection scope of the present invention.

Claims (8)

1. A performance testing device for a packing sealing system for quarter-turn valve stems, including a test bench (10) and a tested component (20) fixed on the test bench (10); the tested component (20) includes The stuffing box (21), packing and valve stem (22) coaxially sleeved from outside to inside are characterized by also including: Medium input system: including a medium input component for inputting medium into the pressure chamber (31a) of the pressure kettle (31) and a medium heating component for heating the medium; the top of the pressure kettle (31) is sealed against at the bottom end face of the stuffing box (21), thereby ensuring that the medium enters the cavity of the stuffing box (21) from the pressure chamber (31a); Packing ballast system: It includes a linear hydraulic actuator (41) that can apply dynamic or static axial load to the packing gland at the top opening of the stuffing box (21). The linear hydraulic actuator (41) passes hydraulic pressure Ballast components provide hydraulic pressure; Driving system: used to drive the valve stem (22) to rotate around the axis of the stuffing box (21) in the cavity of the stuffing box (21); Data acquisition component: used to achieve online acquisition of information and data at each monitoring point, including a medium pressure gauge (51) or a medium pressure sensor used to obtain the medium input pressure at the medium input component, and a pressure chamber (31a) The medium temperature sensor (52) for the internal medium temperature, the hydraulic pressure gauge (53) or hydraulic pressure sensor used to obtain the hydraulic pressure at the packing ballast system, the torque sensor (54) used to obtain the torque of the drive system on the valve stem, and A position sensor (55) for obtaining the current rotational position of the valve stem (22) and a leakage monitor (56) for monitoring medium leakage at the top opening of the stuffing box (21); The packing ballast system includes a tank (42) for containing hydraulic oil. After the hydraulic oil in the tank (42) is pumped out by the hydraulic pump (43), it passes through the hydraulic pressure reducing valve (44) and the accumulator (44) in sequence. 45), the hydraulic check valve (46) and the pressure control valve (47) then enter the P port of the hydraulic reversing valve (48). The T port of the hydraulic reversing valve (48) is directly connected to the fuel tank (42). The hydraulic reversing Ports A and B of the valve (48) are respectively connected to the first chamber and the second chamber of the linear hydraulic actuator (41) through a hydraulic circuit; a hydraulic cut-off valve (49) and a hydraulic valve are arranged on each hydraulic circuit. Pressure gauge (53) or hydraulic pressure sensor; The linear hydraulic actuator (41) includes an outer housing (41a) and a piston rod (41b) that penetrates the outer housing (41a) and can perform reciprocating linear motion along the axial direction of the outer housing (41a). The piston rod (41b) One end used to match the packing gland is the working end. The linear hydraulic actuator (41) also includes a second piston (41) that can push the piston rod (41b) to produce an axial linear motion in the direction of the working end. 41d) and a first piston (41c) coaxially sleeved on the piston rod (41b) and capable of reciprocating sliding motion along the axial direction of the piston rod (41b); the inner cavity wall of the outer shell (41a) and the piston A sleeve-shaped chamber is enclosed between the outer walls of the rod (41b). The first piston (41c) and the second piston (41d) divide the chamber into a space between the first piston (41c) and the upper shell cover. The first chamber (a), the second chamber (b) between the first piston (41c) and the second piston (41d), and the third chamber (b) between the second piston (41d) and the lower shell cover chamber, and the first chamber (a), the second chamber (b) and the third chamber are independent of each other, and the third chamber is connected to the air pressure source or the atmospheric environment through the second gas reversing valve; the first An elastic member (41e) with an elastic direction parallel to the axis of the piston rod (41b) and coaxially sleeved on the outer wall of the piston rod (41b) is arranged between the piston (41c) and the second piston (41d). The elastic member (41e) It is a spring, and the two ends of the elastic member (41e) respectively extend axially and fix the first piston (41c) and the second piston (41d) respectively. 2. A performance testing device for a packing sealing system for a quarter-turn valve stem according to claim 1, characterized in that: the shape of the stuffing box (21) is an integrated body formed by a combination of a valve cover (21a) and a valve housing. It has a cylindrical structure, and the end of the valve cover (21a) of the stuffing box (21) is located at the bottom end of the stuffing box (21); it also includes a structure that is sandwiched between the bottom end of the stuffing box (21) and the pressure kettle (31). To the adapter plate (60) with a transitional connection function, the pressure chamber (31a) of the pressure kettle (31), the cavity of the adapter plate (60) and the cavity of the stuffing box (21) are all coaxially arranged. 3. A performance testing device for a packing sealing system for a quarter-turn valve stem according to claim 2, characterized in that: the medium heating component includes a heater (32) surrounding the periphery of the pressure kettle (31); A pressure relief pipeline connected to the pressure chamber (31a) is also arranged at the bottom end of the pressure kettle (31). The pressure relief pipeline is controlled to open and close through a pressure relief valve (33). 4. A performance testing device for a packing sealing system for a angular stroke valve stem according to claim 3, characterized in that: the medium input assembly includes medium pressure sources (34) sequentially arranged on the medium pipeline along the direction of medium flow. ), medium cut-off valve (35), booster (36), regulating valve (37), medium check valve (38) and safety valve (39); the conduction direction of the medium check valve (38) is In the direction of medium flow, a buffer tank (37a) is arranged between the regulating valve (37) and the booster (36); the medium pressure gauge (51) includes a first medium pressure gauge and a second medium pressure gauge, and the first The medium pressure gauge is arranged on a section of the medium pipeline between the medium pressure source (34) and the medium cut-off valve (35), and the second medium pressure gauge is arranged on a section of the medium pipeline between the medium one-way valve (38) and the medium pressure gauge (51). on a section of media pipeline. 5. A performance testing device for a packing sealing system for a quarter-turn valve stem according to claim 1, characterized in that: the shaft body of the piston rod (41b) located in the third chamber is coaxially provided with an annular step ( 41f), the bottom surface of the second piston (41d) and the upper shoulder of the annular step (41f) form a stop fit that limits the downward movement of the second piston (41d); the bottom end of the piston rod (41b) forms the working end. 6. A performance testing device for a packing sealing system for a angular stroke valve stem according to claim 1, characterized in that: the driving system includes a gas pressure reducing valve (72) connected to a gas source (71), and the first gas The P port and the T port of the reversing valve (73) are respectively connected to the outlet end of the gas pressure reducing valve (72) and the external atmospheric environment. The A port and the B port of the first gas reversing valve (73) are respectively connected through a gas circuit. The air inlet chamber and air return chamber of the pneumatic actuator; a set of speed regulating valves (74) are arranged on each gas circuit; the piston rod (41b) is a sleeve, and the connecting rod (75a) coaxially penetrates The shaft sleeve is coaxially fixed with the valve stem (22); the top end of the connecting rod (75a) is coaxial with the transition rod (75b) and the adjacent ends of the two are connected to each other through the torque sensor (54); The power output shaft of the pneumatic actuator (75) that realizes rotation within a specified angle range is sleeve-shaped, and the power output shaft extends vertically upward to form a first connecting flange (75d), and the transition rod (75b) is coaxial After passing through the power output shaft, a second connecting flange (75c) is arranged at the top of the transition rod (75b); the drive system also includes an electric actuator (76) that can achieve continuous rotation. The power shaft of the actuator (76) extends vertically downward and a third connecting flange (76a) is arranged at the bottom end; the first connecting flange (75d), the second connecting flange (75c) and the third connecting flange The flanges (76a) are coaxial with each other, and the second connecting flange (75c) selects one of the first connecting flange (75d) and the third connecting flange (76a) for flange matching. 7. A performance testing device for a packing sealing system for a quarter-turn valve stem according to claim 2 or 3 or 4, characterized in that: the test bench (10) is a three-layer frame structure, and the lower frame (11) It forms a base that can be placed on the base surface. The middle frame (12) is used to fix the pressure kettle (31), and the upper frame (13) is used to fix the pneumatic actuator (75) and the linear hydraulic actuator (41); the upper frame (13) can produce vertical movement toward and away from the middle frame (12). 8. A test method using a packing seal system performance test device for a angular stroke valve stem as claimed in claim 1 or 2 or 3 or 4, characterized in that it includes the following steps: A0). According to the specifications and dimensions of the component under test (20), adjust the test bench (10) to a suitable height, and pass the component under test (20) through the adapter plate (60) and the middle frame (10) of the test bench (10). 12) to complete the assembly; if the component under test (20) is a continuous rotation type, connect the electric actuator (76) and the valve stem (22) through the transition rod (75b), and complete the locking of the position of the test bench (10) ; If the component under test (20) is a partial rotation type, connect the pneumatic actuator (75) and the valve stem (22) through the transition rod (75b), and complete the locking of the position of the test bench (10); A1), start the hydraulic pump (43), control the hydraulic reversing valve (48) according to the ballast demand of the packing to supply pressure to the designated chamber of the linear hydraulic actuator (41), and adjust the pressure control valve (47) so that The corresponding chamber of the linear hydraulic actuator (41) is slowly pressurized; when the hydraulic pressure in the first chamber or the second chamber of the linear hydraulic actuator (41) increases to the designated pressure PA1, the hydraulic circuit is closed and cut off. And synchronously monitor and record the pressure value changes in the linear hydraulic actuator (41) through the hydraulic pressure gauge (53) or the hydraulic pressure sensor; A2), start the supercharger (36) and the heater (32), and jointly control the supercharger (36), the heater (32) and the pressure relief valve (33) to make the pressure chamber (31a) load stable and balanced to the specified temperature T and pressure PB1, and simultaneously monitor and record the changes in temperature and pressure values in the pressure chamber (31a) through the medium pressure gauge (51) and the medium temperature sensor (52); A3) Use the leakage monitor (56) to monitor whether excessive leakage occurs at the packing seal; if not, proceed to step A4. If yes, depressurize the pressure chamber (31a) and gradually increase the hydraulic pressure to PA2 again. Confirm to close the hydraulic circuit and gas circuit, and re-execute steps A2~A3 in sequence; A4). Start the drive module. If the component under test is of partial rotation type, adjust the speed regulating valve (74) so that the rotation speed V of the pneumatic actuator (75) meets the test requirements. By controlling the first gas reversing valve (73) action, causing the pneumatic actuator (75) to reciprocate several times at a predetermined angle, and the changes in the number of reciprocations, torque value, and angular displacement speed of the valve stem are synchronously monitored and recorded through the torque sensor (54) and the position sensor (55); if If the component under test is a continuous rotation type, the rotation speed V of the electric actuator (76) must meet the test requirements, and the torque value and number of rotations of the valve stem can be synchronously monitored and recorded through the torque sensor (54) and the position sensor (55). , changes in speed value; A5) Use the leakage monitor (56) again to monitor whether excessive leakage occurs at the packing seal; if not, proceed to step A6. If yes, depressurize the pressure chamber (31a) and gradually increase the hydraulic pressure to PA3 again. , confirm to close the hydraulic circuit and gas circuit, and repeat steps A2 to A5; A6), the pneumatic actuator (75) or the electric actuator (76) continues to drive the valve stem (22) to rotate, and the leakage monitor (56) monitors whether excessive leakage occurs at the packing seal in real time, and simultaneously monitors and records each Changes in index values, including but not limited to: the pressure value of the first chamber or the second chamber of the linear hydraulic actuator (41), the pressure value and temperature value of the pressure chamber (31a), the valve stem (22 ) torque value, angular displacement speed or rotation speed, number of reciprocations or number of rotations; until excessive leakage occurs at the packing seal, stop the pneumatic actuator (75) or electric actuator (76), and the pressure chamber (31a) leaks Pressure, then gradually increase the hydraulic pressure to PA4, confirm that the hydraulic circuit and gas circuit are closed, and repeat steps A2 to A5; A7). Organize various index values and obtain test data.