JP3825556B2 - Valve packing test equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a test apparatus that evaluates the performance of a valve packing of a high-temperature and high-pressure valve used in a power plant, for example, and more particularly to a valve packing test apparatus that can accurately evaluate the performance of the valve packing.
[0002]
[Prior art]
In a conventional test apparatus of this type, for example, as shown in FIG. 7, valve packings 23 are set on both sides of a pressure vessel 101 via holding flanges 108, and a load cell 104 is disposed between a shaft 102 and a cylinder 103. In addition, a heater 105 for raising the temperature is disposed outside the pressure vessel 101. The pressure vessel 101 is configured to be supplied with high-pressure water from a water supply tank 106 via a booster pump 107. Then, the shaft 102 is linearly moved by the operation of the cylinder 103, and the total value of the friction resistance of the valve packing 23 and the shaft 102 on both sides is measured by the load cell 104, thereby evaluating the performance of the valve packing 23.
[0003]
[Problems to be solved by the invention]
However, in this test apparatus 100, even if the shaft 102 is reciprocated by the cylinder 103, the volume in the pressure vessel 101 does not change, so that there is an advantage that the pressure control is small and the pressure control is simple. However, there is a problem that it is difficult to accurately measure the performance of the valve packing 23. That is, the load measured by the load cell 104 is measured as the sum of the axial load due to the internal pressure in the pressure vessel 101 and the frictional force between the valve packings 23 provided on both sides of the shaft 102.
[0004]
However, since the valve packing 23 is provided on both sides of the pressure vessel 101 in the test apparatus 100 described above, the frictional force generated by the valve packing 23 measured by the load cell 104 is the total value of the two valve packings 23. Therefore, the frictional resistance between the individual valve packing 23 and the shaft 102 cannot be measured accurately.
[0005]
The measured value of the frictional resistance between the valve packing 23 and the shaft 102 is an extremely important value for evaluating the performance of the valve packing 23. In particular, the measured value is used for a valve packing such as a globe valve which is used in a high temperature and high pressure state and performs a spiral motion. In this case, it is impossible to obtain an accurate evaluation of the valve packing 23 according to the actual machine, and it is actually desired that a test apparatus capable of appropriately evaluating the performance of the valve packing 23 is desired. .
[0006]
The present invention has been made in view of such circumstances, and an object of the present invention is to measure various characteristic values in a state where a spiral motion is applied, and to accurately determine the valve packing. An object of the present invention is to provide a valve packing test apparatus capable of performing a proper performance evaluation.
[0007]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 of the present invention is a test apparatus for evaluating the performance of a valve packing as a sample set in a pressure vessel, wherein the valve is set in the pressure vessel. A spiral motion imparting means capable of imparting a spiral motion to the shaft inserted in a sliding contact with the packing, a pressure control means capable of maintaining a constant pressure in the pressure vessel, and at least an axial load during the spiral motion of the shaft And measuring means capable of measuring.
[0008]
With this configuration, the valve packing as the sample set in the pressure vessel in a state of sliding contact with the shaft spirals by the operation of the spiral motion imparting means, and the pressure in the pressure vessel accompanying the spiral motion is increased. While the fluctuation is controlled by the pressure control means, the pressure in the pressure vessel is kept constant. In this state, the axial load or the like of the shaft is measured by the measuring means, whereby the frictional resistance between the shaft and the valve packing is calculated, and the performance of the valve packing is evaluated. Since the valve pan is evaluated for performance in a spiral motion state rather than a simple linear motion, it is possible to accurately evaluate the performance corresponding to the valve motion even for a valve that spirals, such as a globe valve. .
[0009]
Further, in the invention according to claim 2, the spiral motion imparting means includes a ball spline shaft connected to the shaft via a coupling, a linear drive cylinder for linearly moving the shaft, and a rotational drive for rotating the shaft. And a linear drive cylinder and a rotational drive motor are simultaneously operated to impart a spiral motion to the shaft. By configuring in this way, it is possible to impart a spiral motion to the shaft via the ball spline shaft by simultaneously operating the linear drive cylinder and the rotational drive motor, so the shaft can be configured with a comparatively simple configuration. Stable spiral motion is obtained, and more accurate performance evaluation of the valve packing becomes possible.
[0010]
The invention according to claim 3 is characterized in that the shaft is fitted and inserted in a sliding contact with a valve packing set in the pressure vessel without penetrating the pressure vessel. With this configuration, since the shaft does not penetrate the pressure vessel, the shaft can be brought into sliding contact with one valve packing set in the pressure vessel, and the friction between the valve packing and the shaft corresponding one-to-one. The resistance can be measured accurately, and a more accurate performance evaluation of the valve packing becomes possible.
[0011]
In the invention according to claim 4, the pressure control means has a pressure control pressure vessel having the same shape as the pressure vessel, and the volume of the pressure control pressure vessel follows the pressure fluctuation in the pressure vessel. By varying, the pressure in the pressure vessel is maintained constant. By configuring in this way, when the volume in the pressure vessel increases, for example, the volume in the pressure control pressure vessel of the same shape decreases following this. The pressure can always be maintained constant, and a more accurate performance evaluation of the valve packing becomes possible.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
1 to 5 show an embodiment of a valve packing test apparatus according to the present invention. FIG. 1 is a schematic front view thereof, FIG. 2 is a plan view, FIG. 3 is an enlarged front view of a pressure vessel portion, and FIG. FIG. 5 is a process diagram showing an example of a test method.
[0013]
1 and 2, the test apparatus 1 has a frame 2 formed in a frame shape. On the upper surface of the frame 2, a pressure that can be moved in the directions of arrows A and B in FIG. A container 3 is arranged. One end of a ball spline shaft 5 is connected to the left end side of the flange 4 of the pressure vessel 3, and a thrust joint 6 and a gear 7 are fixed to the other end of the ball spline shaft 5.
[0014]
As shown in FIG. 2, the gear 7 is connected to a rotational drive motor 9 having a torque converter via a belt 8, and the thrust joint 6 has a tip of a cylinder shaft 10 a of a linear drive cylinder 10. Are connected via a load cell 11 as one of measuring means. The rotation driving motor 9, the linear driving cylinder 10, the ball spline shaft 5 and the like constitute a helical motion imparting means.
[0015]
Further, as shown in FIG. 1, a pressure control pressure vessel 13 constituting a pressure control means and a linear drive cylinder 14 for driving the pressure vessel 13 are disposed at the lower part of the gantry 2 as will be described later. An electronic balance 15 that measures the amount of leakage, a pressure gauge 16, an accumulator 17, a water supply tank 18, a booster pump 19, a hydraulic unit 20, and the like are arranged. 1 and 2, reference numeral 21 indicates an inverter, and reference numeral 22 indicates a panel attached to the entire peripheral surface of the gantry 2.
[0016]
The pressure vessel 3 in which the valve packing 23 as a sample is set has a body 26 connected by a high-pressure side flange 25, the flange 4, and a holding flange 27 as shown in an enlarged view in FIG. The shaft 28 is inserted into a hole provided in the flange 4 so as not to penetrate the pressure vessel 3. A valve packing 23 supplied from, for example, a customer via a ring 29 is fitted into a portion of the shaft 28 corresponding to the hole of the flange 4.
[0017]
A pressing flange 27 is connected to the flange 4 by a bolt 30, and a load cell 31 and a cooler 32 are attached to the flange 4 side of the pressing flange 27, and a leak detection port 33 is provided in the flange 4. . The ball spline shaft 5 is connected to a shaft 28 protruding to the left end side of the holding flange 27 via a coupling 34.
[0018]
Further, a pipe joint 35 communicating with a hole inside the body 26 is attached to the front end (right end) side of the body 26, and the side where the valve packing 23 of the pressure vessel 3 is set and the side of the body 26. Heaters 36 and 37 are disposed on one of the slide mechanisms (not shown). The pressure control pressure vessel 13 is similar to the pressure vessel 3 except that the shaft 38 is directly connected to the cylinder shaft 14a of the linear drive cylinder 14 via a coupling 39, as shown in FIG. Since they are formed in the same manner, the same reference numerals are given and detailed description thereof is omitted.
[0019]
Next, the connection state of the piping system of the test apparatus 1 will be described based on the schematic system diagram of FIG. An initial water supply port 42 is connected to the pipe joint 35 of the pressure vessel 3 via a valve 41, and a steam outlet 44 is connected via a safety valve 43. The pipe joint 35 is connected to the pipe joint 35 of the pressure control pressure vessel 13 and to the water supply pipe 45.
[0020]
The water supply pipe 45 has the water supply tank 18 on the uppermost stream side, and a booster pump 19 is connected to the water supply tank 18 via a valve 46, and the booster pump 19 is connected to the pressure vessel 3 via a valve 47. Are connected to the pipe joint 35. The pressure gauge 16, the pressure transducer 48, and the rupture plate 49 are connected to the water supply pipe 45, and the accumulator 17 is connected via a valve 50.
[0021]
A cooling pipe 52 is connected to the leak detection port 33 of the pressure vessel 3, and a lower part of the cooling pipe 52 is connected to the electronic balance 15. The cooling pipe 52 has an inlet side connected to a cooling water inlet 54 via a valve 53 and an outlet side connected to a cooling water outlet 55. The cooling water inlet 54 is connected to the inlet side of the cooler 32 of the pressure vessel 3 and the pressure control pressure vessel 13 via the valve 56, and the cooling water outlet 55 is connected to the outlet side of each cooler 32, respectively. It is connected.
[0022]
On the other hand, the linear drive cylinders 10 and 14 for operating the pressure vessel 3 and the pressure control pressure vessel 13 are connected to the flow regulator 58, the pilot lamp 59 and the solenoid valve 60 through the base block 57, respectively. The hydraulic unit 20 is connected. By the operation of the hydraulic unit 20 and the solenoid valve 60, the linear drive cylinders 10 and 14 are driven, and the cylinder shafts 10a and 14a move linearly. In the above example, the linear movement of the pressure vessel 3 and the pressure control pressure vessel 13 is performed by a hydraulic drive system. However, for example, other appropriate linear drive systems such as air pressure or a combination of an electric motor and a ball screw are used. It can also be adopted.
[0023]
Next, an example of a test method of the valve packing 23 by the test apparatus 1 will be described based on the process diagram of FIG. First, when the measured valve packing 23 is set in the test apparatus 1, the bolt 30 of the holding flange 27 is removed and the pipe joint 35 is removed, and the flange 4, the heaters 36 and 37, the body 26, and the high pressure flange 25 are removed. Is moved in the direction of the arrow a for each slide mechanism, and the shaft 28 is removed from the flange 4. Then, the ring 29 and the valve packing 23 are extracted from the flange 4. As a result, the valve packing 23 whose measurement has been completed is removed from the test apparatus 1.
[0024]
After removing the valve packing 23 after the measurement, the next new sample, the valve packing 23 and the ring 29, are inserted into the flange 4 (K101), and the pressure vessel 3 and the like are moved in the direction indicated by the arrow B (K102) for each slide mechanism. The bolt 30 is tightened (K103). At this time, the tightening torque of the bolt 30 is managed by the load cell 31 according to the characteristics of the valve packing 23. Then, a pipe to the cooler 32, a pipe to the leak detection port 33, a pipe to the pipe joint 35, and the like are attached (K104). Thereby, the setting of the sample is completed.
[0025]
When the setting of the sample is completed, the heaters 36 and 37 are operated (K105) and heated until the body 26 and the flange 4 reach a predetermined temperature. At this time, cooling water is supplied to the cooler 32 (K106) so that the load cell 31 does not reach the limit temperature, and the load cell 31 is cooled. When the operation of the heaters 36 and 37 and the temperature raising process by supplying the cooling water are completed, the valve 41 is opened and water is injected from the initial water supply port 42 (K107). The amount of water injected at this time is determined from the steam table data according to the target temperature and pressure.
[0026]
Then, after injecting water, the booster pump 19 is driven (K108) to increase the internal pressure of the pressure vessel 3. The internal pressure at this time is controlled by a signal from the pressure transducer 48. In addition, since the space between the water supply tank 18 and the valve 46 is not heated, the water in the water supply pipe 45 is in a liquid state at a high pressure, and the accumulator 17, the pressure converter 48, the pressure pump 19 and the like use heat-resistant specifications. There is no need. Further, the pulsation change of the booster pump 19 and the internal pressure change due to the temperature rise can be absorbed by the accumulator 17, and the pressure in the piping system becomes constant. However, even if the pressure excessively rises, the safety valve 43 Or the rupturable plate 49 is operated, and an abnormal increase in pressure is prevented.
[0027]
When the temperature and pressure become constant by the temperature raising process and the pressure raising process, the process proceeds to the measurement process. In this measurement step, first, the linear drive cylinder 10 is operated (K109) by the hydraulic unit 20 and the solenoid valve 60 to linearly move the cylinder shaft 10a, and the belt 8 is connected via the gear 7 outside the ball spline shaft 5. Is driven (K110), and the ball spline shaft 5 is rotated. The rotation speed at this time is arbitrarily set according to the number of times of closing of the actual globe valve.
[0028]
The ball spline shaft 5 and the cylinder shaft 10a of the linear drive cylinder 10 are connected via a thrust joint 6 (K111), whereby a linear motion and a rotational motion are performed simultaneously, and the movement of the shaft 28 is a spiral motion. Become. The spiral movement of the shaft 28 is continuously performed by a timer or a counter (not shown). Usually, the moving speed of the shaft 28 is set to about 300 to 1000 mm / min from the movement of the valve stem of the actual machine.
[0029]
The load applied to the ball spline shaft 5 during this spiral motion is measured by the load cell 11, and the rotational torque is measured by a torque converter (not shown) in the rotational drive motor 9 (K112). The friction resistance of the valve packing 23 is calculated by measuring the load and the rotational torque.
[0030]
By the way, when the shaft 28 moves, the volume of the space inside the body 26 changes greatly, so that the internal pressure fluctuates. This fluctuation of the internal pressure is controlled by the pressure control pressure vessel 13. That is, the pressure control pressure vessel 13 is set to have the same volume as the pressure vessel 3, and the linear drive cylinders 10 and 14 are interlocked with each other in accordance with fluctuations in the internal pressure of the pressure vessel 3. Then the other moves backward). The fluctuation of the internal pressure in the pressure vessel 3 is controlled by the fluctuation of the volume in the pressure control pressure vessel 13 and is always maintained at a constant internal pressure.
[0031]
Once the load and rotational torque are measured, the leakage amount is measured (K113). The measurement of the leakage amount is performed when the performance of the set valve packing 23 is deteriorated or the initial tightening is insufficient, and the steam leaked from the leakage detection port 33 is solidified in the cooling pipe 52. This leakage amount is also important data for evaluating the performance of the valve packing 23.
[0032]
Then, after continuous operation for a certain period (one to several days), the temperature and pressure in the pressure vessel 3 are lowered, the valve packing 23 is taken out (K114), and necessary data (shaft load, rotational torque, tightening torque, leakage) The quantity, temperature, pressure, etc.) are taken into the recorder (K115), and the test of the valve packing 23 is completed.
[0033]
In the above process, the pressure in the pressure vessel 3 is increased and then the pressure is increased. However, the pressure may be increased after the pressure is increased, or the pressure control pressure vessel 13 is rotated in the same manner as the pressure vessel 3. It is also possible to provide a mechanism or the like so as to evaluate the performance of the two types of valve packings 23 in one test.
[0034]
Thus, in the test apparatus 1 of the above embodiment, the linear load cylinder 10 and the rotation drive motor 9 are provided, so that the shaft 28 is in a spiral motion while the shaft load, the rotation torque, and the tightening force are increased. Since data important for performance evaluation of the valve packing 23 such as torque can be measured, the performance of the valve packing 23 can be accurately evaluated based on this data. In particular, since the shaft 28 can be fitted into the valve packing 23 in a state of not penetrating the pressure vessel 3 and the valve packing 23 and the shaft 28 can be made to correspond one-to-one, the friction resistance of each valve packing 23 can be accurately determined. Can be measured.
[0035]
Moreover, since the pressure vessel 13 for pressure control of the same shape is provided in parallel with the pressure vessel 3, and these are interlocked by separate linear drive cylinders 10 and 14, respectively, for example, when the pressure vessel 3 side is pushed The pressure control pressure vessel 13 side is pulled, so that the total volume in the two pressure vessels 3 and 13 can be always kept constant, and the pressure fluctuation in the pressure vessel 3 can be eliminated. Therefore, it is possible to perform highly accurate performance evaluation corresponding to the movement of the actual machine, even with valve packings whose stems spiral, such as globe valves that are frequently used particularly in power plants. Become.
[0036]
Further, since the spiral motion can be imparted to the shaft 28 by the rotational drive motor 9, the linear drive cylinder 10, the ball spline shaft 5, etc., the configuration of the spiral motion imparting means is compared, such that no special parts are required. Thus, the shaft 28 can be made to perform a stable spiral motion. Furthermore, since the pressure in the pressure vessel 3 can be kept constant by the pressure control pressure vessel 13 and the linear drive cylinder 14 having the same shape, the configuration of the pressure control means is compared, for example, the parts can be shared. Can be simplified.
[0037]
Further, for example, if the pressure control pressure vessel 13 is caused to perform a spiral motion similar to that of the pressure vessel 3, the performance evaluation of the two types of valve packings 23 can be performed in one test, and the efficiency of the test is improved. Can be achieved.
[0038]
FIG. 6 is a schematic configuration diagram of a main part showing another embodiment of the test apparatus according to the present invention. In addition, the same code | symbol is attached | subjected to the same site | part as the test apparatus 1 of the said Example, and the detailed description is abbreviate | omitted. The characteristics of the test apparatus 1 of this embodiment are that a cooler 64 and a heater 65 are connected to the pipe joint 35 of the pressure vessel 3 via check valves 62 and 63, and the heater 65 and the cooler 64 are connected to each other. A water supply pipe 45 including an accumulator 17, a booster pump 19, a water supply tank 18 and the like is connected between them.
[0039]
According to the test apparatus 1, the pressure fluctuation in the pressure vessel 3 can be eliminated without providing the pressure control pressure vessel 13, and in addition to the effects similar to those of the above-described embodiment, the normal cycle can be obtained. In order to maintain the heat balance in 1 to 2 minutes, it is somewhat difficult to select the performance of the cooler 64 and the heater 65, but the configuration of the test apparatus 1 can be further simplified and the cost can be reduced. The effect that can be achieved is obtained.
[0040]
In the above embodiment, the case of evaluating the performance of the valve packing 23 that spirally moves like a globe valve for high temperature and pressure has been described as an example, but the present invention is not limited to this. For example, it can also be used for performance evaluation of a general valve packing. In this case, for example, the performance of the valve packing 23 can be evaluated only by the operation of the linear drive cylinder 10 without driving the rotational drive motor 9.
[0041]
Moreover, the shape of the pressure vessel 3 and the pressure vessel 13 for pressure control in the above embodiment, the arrangement structure and piping system diagram of each part of the entire test apparatus 1, the test process diagram shown in FIG. Needless to say, various modifications can be made without departing from the scope of the present invention.
[0042]
【The invention's effect】
As described above in detail, according to the first to fourth aspects of the present invention, the valve packing is provided with a helical motion on the shaft in sliding contact, and the pressure in the pressure vessel is maintained constant. Since the axial load or the like is measured, for example, the friction resistance between the shaft and the valve packing is accurately calculated, and the performance evaluation of the valve packing can be performed with high accuracy.
[Brief description of the drawings]
FIG. 1 is a schematic front view showing an embodiment of a valve packing test apparatus according to the present invention. FIG. 2 is a plan view thereof. FIG. 3 is an enlarged front view of the pressure vessel portion. FIG. 5 is a process diagram showing an example of the test method. FIG. 6 is a schematic configuration diagram of a main part showing another embodiment of the valve packing test apparatus according to the present invention. FIG. 7 is a conventional test apparatus. Sectional view showing the main part 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Test apparatus 3 Pressure vessel 4 Flange 5 Ball spline shaft 6 Thrust joint 9 Rotation drive motor 10 Linear drive cylinder 11 Load cell 13 Pressure control pressure vessel 14 Linear drive cylinder 15 Electronic balance 23 Valve packing 25 High pressure side flange 26 Body 27 Holding flange 28 Shaft 29 Ring 30 Bolt 31 Load cell 32 Cooler 33 Leak detection port 35 Piping joint 36, 37 Heater 45 Water supply piping

Claims (4)

A test apparatus for evaluating the performance of a valve packing as a sample set in a pressure vessel, and a helix capable of imparting a spiral motion to a shaft fitted in a sliding contact state with the valve packing set in the pressure vessel It is provided with a motion imparting means, a pressure control means capable of maintaining a constant pressure in the pressure vessel, and a measuring means capable of measuring at least an axial load during the helical motion of the shaft. Valve packing test equipment. The spiral motion imparting means has a ball spline shaft connected to the shaft via a coupling, a linear drive cylinder for linearly moving the shaft, and a rotary drive motor for rotating the shaft, 2. The valve packing test apparatus according to claim 1, wherein a helical motion is imparted to the shaft by simultaneously operating a driving cylinder and a rotational driving motor. 3. The valve packing test apparatus according to claim 1, wherein the shaft is fitted and inserted in a sliding contact state with a valve packing set in the pressure vessel without penetrating the pressure vessel. 4. The pressure control means has a pressure control pressure vessel having the same shape as the pressure vessel, and the volume of the pressure control pressure vessel fluctuates following the fluctuation of the pressure in the pressure vessel. The valve packing test apparatus according to claim 1, wherein the pressure is maintained constant.

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