RU2518798C1 - Method for leakproofness test of pipeline fitting gate (wedge gate valve) and device for its implementation - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: definition of the state of a wedge gate valve consists in checking the compliance of a parameter with the requirements of technical documentation (specification, certificate) issued by the manufacturer. Roughness of seat sealing surfaces in the gate of the valve which are functionally related to leak tightness is used as a parameter being tested (controlled). A wedge gate valve with a device for gate leakproofness testing without the valve deinstallation from a pipeline comprises a casing, a cover, a wedge, seats in the gate with sealing surfaces with tested roughness parameters, a drain plug. The device is fitted by a reference model which is rigidly connected to the plug, is projecting either above the seats in the valve casing passage or above the inner pipeline surface, is turned by its flat controlled surface toward the medium flow running through the passage in the valve casing in the period of its testing.

EFFECT: faster testing of a gate valve due to its adaptation for diagnostic check without being demounted from a pipeline.

2 cl, 3 dwg

Description

The proposed inventions relate to the field of mechanical engineering - valve engineering and are intended to determine the state of stop valves - wedge gate valves, its most important parameter is the tightness of the valve without dismantling it from the pipeline.

Determining the state of stop valves consists in checking the compliance of the parameter with the requirements of the technical documentation (TU, passport) of the manufacturer. Violation of tightness standards in the gate valve can lead to losses in flows, impair its functionality as a stop valve.

A device is known for diagnosing an electric wedge gate valve without dismantling it from a pipeline (see Japan, Application No. 2000065246 (A), M. CL F16K 31/04, F16K 37/00, published March 03, 2000).

The device is designed to measure the actual load transmitted to the locking element (wedge) from the electric drive through the spindle, in particular, when the passage in the valve body is blocked by the locking element. The tightness in the shutter is determined indirectly - through the force transmitted from the electric drive to the locking element through the spindle.

The disadvantage of this device is the unsatisfactory accuracy of diagnosing leak tightness in the shutter, which is explained by the use of a functional model and the obtaining of diagnostic results analytically.

Another electric wedge gate valve is known, in which the measurement of the load transmitted from the electric drive through the spindle to the locking element (wedge) is carried out in accordance with a known method and device (see US patent No. 4570903, M. class F16K 37/00, NKI 251 -129.12, published February 18, 1986).

Using the device, the actual load transmitted through the spindle from the electric drive to the locking element (wedge) is measured. The tightness value is determined analytically using a functional model without dismantling the valve from the pipeline.

The disadvantage of this method and device is that using the functional model it is not always possible to determine analytically the causes of leakage in the shutter, in particular when there are deviations in geometric and structural parameters in the sealing elements, as well as defects that lead to a violation of the shutoff function pipe fittings: jamming; destruction and deformation of parts in the shutter.

The latter method and device according to US patent No. 4570903 for the technical nature and purpose are closest to the claimed method and device.

In the claimed object, data on the state of the sealing surfaces in the valve gate valve is determined by their actual state without dismantling the valve from the pipeline, which is almost impossible without disrupting the process of its operation.

The objective of the proposed inventions (method and device) is to accelerate the process of diagnosing a valve by adapting it for diagnostic monitoring, aimed ultimately at reducing the repair cycle of operated shutoff valves and increasing the overhaul period.

The problem in the proposed wedge gate valve with a device for diagnosing valve tightness without dismantling it from a pipeline containing a housing, a cover, a locking element (wedge), seats in the valve with sealing surfaces with controlled roughness parameters, a drain plug, is solved by the fact that the device is equipped with a sample rigidly connected with a plug protruding either above the seats into the passage of the valve body, facing a flat controlled surface towards the medium flow, or above the inside the pipeline, facing a flat controlled surface towards the flow of fluid flowing through the passage in the valve body during its diagnosis.

The presence of a drain plug with a sample fixed on it made it possible to adapt it (plug) to the diagnosed control without dismantling the valve from the pipeline. After the diagnosis period is over, the pressure in the pipeline on which the diagnosed valve is installed is removed, the plug with the sample is removed, and the drain hole is closed with another plug. After that, they control the surface of the sample and make a conclusion about the wear of the sealing surfaces in the valve gate.

The problem is solved in the proposed method for diagnosing the tightness of the shutter valve wedge gate valve, which measures the roughness parameters of the sealing surfaces on the seats in the valve without removing it from the pipeline and compares the roughness parameters with the standard value of the roughness of the sealing surfaces of the seats in the valve gate. The cavity of the valve being diagnosed is released from the working (test) medium and pressure, it is installed and fixed either between the seats in the passage of the valve body or in the wall of the pipeline, in its internal cavity, a sample with adequate roughness parameters and material grade of its controlled surfaces is exposed to the medium flow under excessive pressure in the time interval, after which the sample is removed, compare the parameters on its controlled surfaces with the standard value of the roughness parameters of the shut-off valves and produce the registration and indication of the difference between these values.

The use of a replaceable sample in the process of diagnosing a wedge gate valve made it possible to adapt it to a diagnosed control without dismantling it from the pipeline.

The technical result for the proposed method and a wedge gate valve with a device is to accelerate the process of diagnosing the tightness of a wedge gate valve without dismantling it from the pipeline by using a replaceable sample and quickly registering measurements automatically in analog mode while simultaneously reporting leak tightness.

Accelerating the diagnosis is aimed at reducing the cost of repairing stop valves, to reduce the repair cycle and increase the overhaul period of operated pipeline valves.

The drawings illustrate, as an example, the implementation of the proposed inventions "Method for diagnosing the tightness of a wedge gate valve and a wedge valve with a device for its implementation", confirming the possibility of their industrial use when using the whole set of features, where

figure 1 - wedge gate valve;

figure 2 - remote element I of the mount sample;

figure 3 - samples in disassembled form.

As a diagnosed (controlled) parameter in the inventive method and a wedge gate valve with a device, the roughness of the sealing surfaces of the seats in the gate valve and the possibility of its control in the process of diagnosing the valve without dismantling it from the pipeline are used. In the process of diagnosing a lock wedge gate valve, the following (controlled) roughness parameters of the sealing surfaces of the seats in the valve R _a , R _max , S _m , are used.

where R _a is the arithmetic mean of the deviations of the profile within the base length, mm;

R _max - the maximum height of the bumps, microns;

S _m - the arithmetic mean of the pitch of the irregularities of the profile within the base length, mm The list of roughness parameters can be expanded.

The electric wedge gate valve (see FIG. 1) comprises a housing 1 with connecting pipes 2, 3. A cover 4 is sealed to the housing 1 to form a cavity “a”. Between the sealing elements 5 on the saddles in the housing 1 (the passage in the housing is ajar) a locking element (wedge) 6 is installed, connected to the electric drive 7 through the spindle 8. The movable locking element 6 together with the sealing elements 5 form a shutter. The valve is installed on the pipeline (not shown) and connected to it hermetically by the ends of the nozzles 2, 3.

A threaded hole is made in the lower part of the housing 1, in its wall against the locking element 6, in which a drain plug 9 is installed with a blind cylindrical hole facing the locking element 6. A combined sample made of two semi-cylindrical elements 10 and 11 is rigidly installed in the hole. The flat surfaces "b" and "b1" elements 10 and 11 are paired with each other with the formation of a cylindrical surface for matching it with the cylindrical surface of the hole in the plug 9 so that other surfaces and “c” and “d” on the sample 10 were located above the level of the lower part of the sealing surfaces 5 on the seats in the housing 1. This is necessary for the free flow of the flowing medium on the surface “c” and “d” of the sample 10 with an open passage in the housing 1 gate valve. A drain plug 9 with samples 10 and 11 can be installed in the wall of the pipeline protruding above its inner surface.

The flat surfaces “b”, “b1”, “c”, “d” on samples 10, 11 are designed to simulate the seal in the gate, they are measured and certified by a combination of roughness parameters prior to assembly. Certification data is entered into the database.

The roughness parameters for the samples 10, 11 installed in the body of the valve being diagnosed are checked correspond to the parameters of the sealing surfaces on the seats in the valve shutter. The material of the samples, especially on their flat surfaces exposed to the flow of medium flowing through an open passage in the valve, corresponds to the material deposited on the sealing surfaces of the seats in the valve.

The device operates as follows. Samples 10, 11 are installed in the blind hole of the drain plug 9, as shown in figure 2, after which the plug 9 is screwed into the threaded hole in the wall of the housing 1 against the locking element 6. There is no medium in the housing. Samples 10, 11 are set so that the flat surface “c” on sample 10 is facing the flow flowing through the valve, and is in the zone of the hole in its passage, after which the medium is supplied under a certain pressure through the pipeline through the tested valve and opened passage, lifting the locking element 6 (see figure 1). Samples 10, 11 in the flow of the medium withstand a certain period of time, for example, corresponding to the overhaul cycle, after which they certify their functional surfaces according to the parameters R _a , R _max , S _m and compare with the initial state of the samples. If the wear of the sample exceeds the standard value, then the diagnosed valve is sent for repair. Otherwise, the valve shall be considered serviceable.

The proposed method for diagnosing the tightness of the valve shutoff valves (electric wedge gate valves) is aimed primarily at adapting the object for diagnosis (suitability) without dismantling it from the pipeline.

For this, as a diagnostic (controlled) parameter in the claimed method, the roughness of the sealing surfaces of the seats in the valve gate, its parameters R _a , R _max , S _{m are used} . To monitor these parameters in the process of diagnosing the valve without dismantling it from the pipeline, the cavity of the valve being diagnosed is released from the working medium and pressure, a sample 10 with adequate roughness parameters and material is installed between the seats with sealing elements 5 in the passage of the housing 1 and fixed in a blind drain hole plugs 9 using sample 11 (see drawing of figure 2). After that, it is exposed in a stream of medium under excess pressure in a time interval. At the end of the time cycle, the pressure of the medium in the valve body 1 is dropped, the plug 9 with sample 10 is removed from the housing 1, the roughness parameters “c” and “d” are measured on its surface, they are compared with the standard value of the roughness parameters of this valve, and registration and indication are made differences of these quantities. If the wear of the surface "c" and "d" of sample 10 exceeds the standard value, then the diagnosed valve is sent for repair. Otherwise, the valve shall be considered serviceable.

The list of positions to the application for the proposed invention "Method for diagnosing the tightness of the valve shutoff valves (wedge gate valves) and a device for its implementation"

1 - case

2 - pipe

3 - pipe

4 - cover

5 - sealing element

6 - locking element (wedge)

7 - electric drive

8 - spindle

9 - drain plug

10 - the sample is long

11 - sample short

“A” - cavity in the valve body

"B" is the flat surface of the sample 11

"B1" is the flat surface of the sample 10

"C", "d" - flat surfaces of the sample 10

Claims (2)

1. A wedge gate valve with a device for diagnosing valve tightness without dismantling it from the pipeline, comprising a housing, a cover, a wedge, seats in the valve with sealing surfaces with controlled roughness parameters, a drain plug, characterized in that the device is equipped with a sample connected rigidly to the plug, protruding either above the saddles in the passage of the valve body, or above the inner surface of the pipeline facing a flat controllable surface towards the flow of medium flowing through the passage to gate valve during diagnosis. 2. A method for diagnosing the tightness of a wedge gate valve, in which the roughness parameters of the sealing surfaces on the seats in the valve are measured without dismantling it from the pipeline and the measured roughness parameters are compared with the standard roughness values of the sealing surfaces of the seats in the valve valve, characterized in that the cavity of the diagnosed pipeline fittings is released from the test medium and pressure, install and fix either between the seats in the passage of the valve body, or in the wall of the pipeline, in its internal cavity, a sample with adequate roughness parameters and the material grade of its controlled surfaces is exposed to the flow of medium under excessive pressure in the time interval, after which the sample is removed, the roughness parameters on its controlled surfaces are compared with the standard value of the roughness parameters of this wedge gate valve and produced registration and indication of the difference of these values.

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