JP5684322B2 - Valve seat tilt detection method and valve seat tilt detection device - Google Patents

Description

  The present invention relates to a valve seat tilt detection method and a valve seat tilt detection device. More specifically, the present invention relates to a valve seat tilt detection method capable of detecting a tilt of a valve seat of a safety valve or the like provided in a pressure vessel of a boiler, for example, a tilt or unevenness from a design value by an on-site inspection. And a valve seat inclination detection device.

  As an apparatus for measuring the flatness of a valve seat surface, for example, there is one disclosed in Patent Document 1. This flatness measuring device detects the displacement of the valve seat surface by inserting a base plate with a displacement meter into the housing of the valve device in the spent nuclear fuel reprocessing plant, with the displacement meter facing the valve seat surface. It is a dedicated device. Therefore, this flatness measuring device has a complicated structure and is a large-scale and expensive device. Therefore, the flatness measuring device cannot be used for the inspection of the inclination of the valve seat of the safety valve of the boiler pressure vessel.

  On the other hand, for example, for a safety valve of a pressure vessel of a boiler, it is required to inspect the inclination (unevenness, inclination from a design value, etc.) of the valve seat when an abnormality such as a pressure leak occurs or during periodic inspection. This inspection of the valve seat is performed at the site where the boiler is installed because it is difficult to remove the valve seat from the valve main body of the safety valve and perform a single inspection. This is shown in FIG. 4 and FIG. Since the valve seat 101 is provided in the middle of the flow path 103 in the valve body 102 and can be visually observed from the opening 104 into which the valve body is inserted, the valve seat 101 is exposed with the valve body removed and the opening 104 exposed. Inspection is performed.

  The valve seat 101 is inspected by placing a base plate 105 on the valve seat 101, connecting a horizontal arm 107 to a column 106 extending vertically from the base plate 105, and connecting a dial gauge 108 attached to the horizontal arm 107 to the imprinting portion 109 of the opening 104. This is done by measuring the distance. The measurement is performed for a plurality of measurement positions by changing the direction of the horizontal arm 107 and shifting the measurement position 110 by the dial gauge 108 in the circumferential direction.

  When the valve seat 101 has an abnormal inclination such as an inclination or unevenness, the base plate 105 on the valve seat 101 is inclined and the support column 105 is inclined. Therefore, the measurement values at the measurement positions 110 shifted in the circumferential direction vary. Arise. Therefore, it is possible to detect an abnormal inclination such as the inclination or unevenness of the valve seat 101 based on the variation of each measurement value.

JP 2000-298015 A

  However, in the above-described inspection method, although the original inspection object is the valve seat 101, since the stamping part 109 of the opening 104 is directly measured, the reliability of the inspection result is poor. Further, since the measurement is performed with the base plate 105 placed on the entire valve seat 101, it is not possible to detect the partial unevenness of the valve seat 101.

  It is an object of the present invention to provide a valve seat tilt detection method and a valve seat tilt detection device for a valve such as a safety valve capable of directly measuring a valve seat and detecting a partial abnormality. To do.

  In order to achieve this object, the invention according to claim 1 is a valve seat inclination detecting method in which a valve seat is provided in the back of the opening of the valve body in parallel with the stamping part of the opening. A measuring instrument that measures the distance to the valve seat in a non-contact manner is supported with the valve seat facing the valve seat, and the bridge remains in the circumferential direction of the stamping part while maintaining the same positional relationship between the bridge and the measuring instrument. The distance from the measuring device to the valve seat is measured at a plurality of positions, and the inclination of the valve seat is detected based on the variation in the measured values at each position.

  According to a second aspect of the present invention, in the valve seat inclination detecting device for a valve in which the valve seat is provided in the back of the opening of the valve body in parallel with the stamping part of the opening, A bridge that can change the direction of the seal to the circumferential direction of the stamping part, a measuring instrument that measures the distance to the valve seat in a non-contact manner, and is attached to the bridge and supports the measuring instrument in a state facing the valve seat, Supporting means capable of maintaining the positional relationship between the measuring instrument and the bridge constant, and the measuring instrument measures the distance to the valve seat at different positions in the circumferential direction as the direction of the bridge is changed. .

  In the present invention, since the valve seat is the direct measurement object, the reliability of the abnormal inclination detection can be improved as compared with the case where the stamping part is the direct measurement object. Further, since the distance from the valve seat is measured by the measuring instrument, not only the overall inclination but also the partial unevenness can be detected. Furthermore, since the measurement is performed based on the stamped part that is generally processed with high accuracy, it is possible to detect the abnormal inclination such as the inclination and unevenness of the valve seat with higher accuracy.

An example of embodiment of the valve-seat inclination detection method of the valve | bulb of this invention is shown, (A) is a top view which shows the mode of a test | inspection, (B) is sectional drawing which shows the mode of a test | inspection. It is a top view of the state which removed the valve body etc. from the valve main body of the safety valve. It is sectional drawing of a safety valve. It is sectional drawing which shows the valve seat inclination detection method of the conventional safety valve. It is a top view which shows the measurement position by the valve-seat inclination detection method of the conventional safety valve.

  Hereinafter, the configuration of the present invention will be described in detail based on the form shown in the drawings. In this embodiment, the case where the present invention is applied to a safety valve will be described. However, the object of application is not limited to a safety valve, and may be a valve provided with a valve seat in the back of the opening of the valve body in parallel with the stamping portion of the opening. If applicable.

  1 to 3 show an example of an embodiment of a valve seat inclination detecting device for a valve of the present invention. First, the safety valve to be inspected will be described. The safety valve 1 is provided, for example, in a pressure vessel of a boiler, and a valve seat (valve seat) 4 is provided in the middle of the flow path 3 in the valve body 2 in which the inlet 2a and the outlet 2b are formed. It has been. In addition, an opening 2c for inserting a valve body (valve) 5 is provided at a position facing the valve seat 4 of the valve body 2, and the valve body 5 is attached to a flange 2d around the opening 2c. A protective cylinder 7 that accommodates a spring 6 that presses against 4 is connected. Between the valve body 2 and the protective cylinder 7, a packing 8 for sealing the inside of the valve body 2, a guide 9 for guiding the valve body 5, and a holder 10 for guiding the stay 5a of the valve body 5 are sandwiched. The guide sleeve 9a of the guide 9 and the valve body 5 are sealed by an O-ring (not shown). The valve body 5 moves along the guide sleeve 9a. Around the opening 2c, there is provided a stamping part 2e for sandwiching the packing 8, and the valve seat 4 is provided in parallel to the stamping part 2e. The valve seat 4 and the stamping part 2e have an annular shape. Moreover, the valve seat 4 of this embodiment is provided coaxially with the stamping part 2e.

  Although the safety valve 1 of this embodiment is provided so that the valve seat 4 may become horizontal and the moving direction of the valve body 5 is made into the perpendicular direction, the direction of the safety valve 1 is not restricted to this.

  The applicable safety valve 1 is not limited to the safety valve 1 provided in the pressure vessel of the boiler, and a valve seat 4 is provided in the back of the opening 2c of the valve body 2 in parallel with the stamping part 2e of the opening 2c. Applicable to any safety valve.

  The valve seat inclination detection device (hereinafter simply referred to as a valve seat inclination inspection device) of the safety valve 1 according to the present invention has a valve seat 4 provided in the back of the opening 2c of the valve body 2 in parallel with the stamping portion 2e of the opening 2c. A bridge 11 that is bridged over the stamping part 2e and can change the direction of the bridge to the circumferential direction of the stamping part 2e, and the valve seat 4 A measuring instrument 12 that measures the distance in a non-contact manner and attached to the bridge 11, supports the measuring instrument 12 in a state of facing the valve seat 4, and can maintain the positional relationship between the measuring instrument 12 and the bridge 11 constant. The measuring device 12 measures the distance to the valve seat 4 at different positions in the circumferential direction according to the change of the direction of the bridge 11.

  The valve seat inclination inspection device is used in a state in which the protective cylinder 7, the valve body 5, the packing 8, the guide 9, and the holder 10 are removed from the valve body 2 to expose the opening 2c. When the bridge 11 is placed so as to be bridged over the stamping part 2e of the opening 2c of the valve body 2, the measuring instrument 12 faces the valve seat 4 with a predetermined interval.

  The bridge 11 is bridged over the stamping part 2e of the opening 2c of the valve body 2, and it is preferable to use a bridge that is difficult to bend even if the measuring instrument 12 and the support means 13 are placed thereon. In the present embodiment, a stainless steel plate material having a thickness of 12 mm is used as the bridge 11, but is not limited thereto. The surface of the bridge 11 is preferably flat, for example, the flatness is preferably 3/100 or less. The length of the bridge 11 is substantially the same as the outer diameter of the stamping part 2e, and the bridge 11 is bridged so as to pass through the center of the opening 2c by placing both ends on the stamping part 2e. Moreover, since the bridge 11 is merely placed on the stamping part 2e and is not locked or the like, the direction can be easily changed by lifting the bridge 11.

  The measuring instrument 12 measures the distance from the valve seat 4 in a non-contact manner, and uses a laser distance meter in the present embodiment, but is not limited to this as long as it can measure in a non-contact manner. Since the non-contact measuring instrument 12 is used, the valve seat 4 is not damaged. The measuring instrument 12 is attached to the bridge 11 using support means 13.

  In this embodiment, a magnet base with a holding arm (hereinafter simply referred to as a magnet base 13) is used as the support means 13, but the present invention is not limited to this. The length and angle of the holding arm of the magnet base 13 are adjusted such that the measuring instrument 12 faces the valve seat 4 with a predetermined interval when the bridge 11 is placed on the stamping part 2e. Since the valve seat 4 and the stamping part 2e of this embodiment are provided coaxially, the measuring instrument 12 can be installed even if the bridge 11 is rotated and changed in direction by attaching the magnet base 13 to the center of the upper surface of the bridge 11. Can always face the annular valve seat 4.

  Next, a valve seat tilt detection method (hereinafter simply referred to as a valve seat tilt detection method) of the safety valve 1 of the present invention will be described. The valve seat inclination detection method detects the inclination of the valve seat 4 of the valve seat 4 of the safety valve 1 in which the valve seat 4 is provided in the back of the opening 2c of the valve body 2 in parallel with the stamping part 2e of the opening 2c. The measuring instrument 12 that spans the bridge 11 over the stamping part 2e and measures the distance to the valve seat 4 in a non-contact manner is supported in a state facing the valve seat 4, and the position of the bridge 11 and the measuring instrument 12 is While maintaining the same relationship, the bridge 11 is rotated in the circumferential direction of the stamping part 2e to measure the distance from the measuring instrument 12 to the valve seat 4 at a plurality of positions 14, and based on variations in measured values at each position 14. The inclination of the valve seat 4 is detected.

  The inclination of the valve seat 4 of the safety valve 1 can be measured by removing the protective cylinder 7, the valve body 5, the packing 8, the guide 9, and the holder 10 from the valve body 2, exposing the opening 2c, and viewing the valve seat 4 from the opening 2c. Done in state. The bridge 11 of the valve seat inclination detecting device is placed over the stamping part 2e of the opening 2c, the holding arm of the magnet base 13 is adjusted, and the measuring instrument 12 is opposed to the valve seat 4. In this state, the distance to the valve seat 4 is measured by the measuring instrument 12.

  Next, the direction of the bridge 11 is changed, and measurement is performed at a plurality of locations while shifting the measurement position of the valve seat 4 in the circumferential direction (FIG. 2). In the present embodiment, measurement is performed at a total of four locations while shifting the measurement position 14 by 90 degrees. However, the number of measurement positions 14 is not limited to four, and may be two, three, or five or more. Further, the shifting angle does not need to be precise, and may be an approximate angle.

  The positional relationship between the bridge 11 and the measuring instrument 12 is maintained constant by the magnet base 13 throughout all measurements. Therefore, if the valve seat 4 has an abnormal inclination such as an inclination or unevenness from the design value, the measurement values vary. Therefore, the abnormal inclination of the valve seat 4 can be detected based on the variation of each measured value.

  In the present invention, since the valve seat 4 is a direct measurement object, the reliability of detection is excellent as compared with the case where the stamping part 104 is a direct measurement object as shown in FIG.

  Further, since the distance from the valve seat 4 is measured by the measuring instrument 12, partial unevenness can be detected.

  Further, the bridge 11 is placed on the stamping part 2e, and the valve seat 4 is measured by the measuring instrument 12 whose positional relationship with the bridge 11 is fixed. Therefore, the stamping part 2e is used as a reference plane, and the reference plane and the valve seat 4 are measured. The variation of the distance in the axial direction is measured. The stamping part 2e serving as a reference surface is a sheet surface of the packing 8, and is processed with high accuracy. Since the measurement is performed on the basis of this accuracy surface (the stamping part 2e), the abnormal inclination of the valve seat 4 can be accurately detected.

  In addition, since a commercially available product widely used as a magnet base 13 with a holding arm or a laser distance meter can be used as it is, a valve seat inclination detecting device can be manufactured at low cost and measurement can be performed at low cost. Can do.

  In the present embodiment, since the length of the bridge 11 is substantially the same as the outer diameter of the stamping part 2e, the positioning of the measuring instrument 12 is easy. That is, by making the length of the bridge 11 substantially the same as the outer diameter of the stamping part 2e, the center of the opening 2c can be passed even if the orientation of the bridge 11 is changed, The attached magnet base 13 can always be arranged at the center of the opening 2c. Therefore, even if the bridge 11 is rotated to change the direction, the measuring instrument 12 always faces the annular valve seat 4, and no special position adjustment for making the measuring instrument 12 face the valve seat 4 is necessary. Excellent workability.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the above description, the valve seat 4 provided coaxially with respect to the stamping part 2e of the opening 2c is targeted. However, by moving the bridge 11, the measuring device 12 is moved to the valve seat 4 at a plurality of locations. The valve seat 4 may not be coaxial with the stamping part 2e as long as it can be opposed to the stamping part 2e.

  In the above description, the length of the bridge 11 is substantially the same as the outer diameter of the stamping part 2e, but may be shorter as long as it can be bridged over the stamping part 2e. In this case, the bridge 11 may be deviated from the center of the opening 2c (out of the diameter), but the position of the bridge 11 may be adjusted so that the measuring instrument 12 faces the valve seat 4.

DESCRIPTION OF SYMBOLS 1 Safety valve 2 Valve body 2c Opening 2e Sealing part 4 Valve seat 11 Bridge 12 Measuring instrument

Claims (2)

  In the valve seat inclination detection method in which the valve seat is provided in the back of the opening of the valve body in parallel with the stamping part of the opening, a bridge is bridged over the stamping part and the distance to the valve seat is contactless. A measuring instrument to be measured is supported in a state of facing the valve seat, and the bridge is rotated in the circumferential direction of the stamping portion while maintaining the same positional relationship between the bridge and the measuring instrument at a plurality of positions. A valve seat tilt detection method, comprising: measuring a distance from the measuring device to the valve seat; and detecting the tilt of the valve seat based on variations in measured values at each position.   In a valve seat inclination detecting device for a valve in which a valve seat is provided in the back of the opening of the valve body in parallel with the stamping portion of the opening, the valve seat is spanned over the stamping portion, and the direction of the spanning is set in the circumferential direction of the stamping portion. A bridge that can be changed to a valve, a measuring device that measures the distance to the valve seat in a non-contact manner, and is attached to the bridge and supports the measuring device in a state of facing the valve seat, and the measuring device, Support means capable of maintaining a constant positional relationship with the bridge, and the measuring instrument measures the distance to the valve seat at different positions in the circumferential direction according to the change of the direction of the bridge. A valve seat inclination detecting device for a valve.

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