RU2393380C1 - Method for measurement of gas flow through untight gate of closed ball valve of stop and control valves of manifold pipeline and device for its implementation - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: in method, which consists in connection of drain tube to cavity of valve and measurement of static pressures in pipelines of high and low pressures, and also in cavity of ball valve, additionally high pressure pipeline is connected to drain tube, and in established mode gas flow is measured in it through seal between valve cavity and low pressure pipeline, then low pressure pipeline is connected with further measurement of gas flow in drain tube through seal between high pressure pipeline and cavity of ball valve. Device additionally comprises pulse tubes of high and low pressures, the first and second flow metres and third stop valve, besides high pressure pulse tube is installed between high pressure pipeline and drain tube, and low pressure pulse tube - between drain tube and low pressure pipeline, besides the first flow metre with according stop valve are serially installed in the first pulse tube, and the second flow metre with according stop valve are serially installed in the second pulse tube.

EFFECT: possibility to separately measure flows through seals of stop and control valves by direct method with the help of flow metres.

7 cl, 1 dwg

Description

The group of inventions relates to methods and means of transporting gases and liquids and can be used to test shut-off and control valves (ZRA) of the main pipeline (MT).

There is a method of the same purpose, which consists in pulsed injection into the stream of transported gas at the entrance to the switchgear of a portion of the indicator gas forming the mark, and recording with the help of concentration sensors the delay time of the mark when it passes the ballast, in addition, the spatial broadening of the mark after passing ZRA.

By the delay time and the broadening value of the mark, the volumetric flow rate of the transported gas is measured through the ZRA / RF patent No. 2317482, cl. F17D 5/02, 2007 /.

A known system for a similar purpose, containing an indicator gas injector and indicator gas concentration sensors located on opposite sides of the air defense system at a known distance from the injector / RF patent No. 2309323, class. F17D 5/02, 2007 /.

In an analogue, the transit time of the known gas and the indicator gas (tag) and the concentration of the indicator gas in the tag are measured by which the flow rate of the transported gas through the leaky shutter of a closed ball valve ZRA is measured.

The disadvantage of the analogs of the method and device is the low accuracy of determining the gas flow rate through the ZRA associated with the fuzziness of the mark and the inability to determine the gas flow rate separately through each ZRA seal.

There is a method of the same purpose, which consists in connecting a drain tube to the tap cavity of the CRA and measuring static pressures in the high and low pressure pipelines, as well as in the cavity of a ball valve / Kaluzhskikh A.N. "Ball valves: tightness control in the conditions of the existing compressor station of the main gas pipeline." Review.inform. Ser. Transport and underground gas storage. - M .: IRC Gazprom LLC, 2002, p. 20, 21 /.

This method is adopted as a prototype.

In the prototype, the static pressure in the drainage tube is measured with an open and closed drainage valve. This allows you to draw up a system of equations, solving which you can determine the gas flow through the damaged seal ball valve.

A device of the same purpose is known, adopted as a prototype, containing a drainage tube with a shut-off valve connected to the valve cavity, and three pressure gauges connected to the high and low pressure pipelines and the MT ball valve cavity, and an additional shut-off valve / A. Kalugskikh "Ball valves: tightness control in the conditions of the existing compressor station of the main gas pipeline." Review.inform. Ser. Transport and underground gas storage. - M .: IRC Gazprom LLC, 2002, p. 22-25, Fig. 8 /.

In the prototype, a chamber is connected to the drainage tube, in the cover of which a calibrated hole is made, and the rate of gas outflow from this calibrated hole, expressed in terms of gas parameters, is measured.

Then, according to the mathematical ratio, the gas flow through the leaky shutter ZRA is determined.

The disadvantage of the prototypes of the method and device is the low accuracy of the gas flow measurement associated with a large number of assumptions in the preparation of equations from which the gas flow is determined, and the impossibility of direct measurement of gas flow (leakage) through each valve seal separately.

The technical result obtained from the introduction of the method and device is to increase the accuracy of measurements by using the direct method of measuring flow (leakage), as well as the ability to measure gas flow separately through each seal of the failed valve ZRA.

This technical result in terms of the method is achieved due to the fact that in the known method, which consists in connecting the drain pipe to the cavity of the tap and measuring the static pressures in the high and low pressure pipelines, as well as in the cavity of the ball valve, the high pressure pipe is additionally connected to the drain pipe and in the steady state, the gas flow rate is measured in it through the seal between the valve cavity and the low pressure pipe, and then the low pressure pipe is connected, followed by measurement a drainage tube the gas flow through the seal between the pipe and the high pressure ball valve cavity.

The steady-state time when measuring gas flow rates through ball valve seals is determined, respectively, by the equality of static pressures in the valve cavity and low pressure pipe, and in the valve cavity and high pressure pipe.

The technical result in part of the device is achieved due to the fact that in the known device containing a drainage tube with a shut-off valve connected to the valve cavity, and three pressure gauges connected to the high and low pressure pipelines, as well as to the cavity of the ball valve of the main pipeline, high and low pressure impulse pipes, first and second flow meters and a third shut-off valve, while a high pressure impulse pipe is installed between the high pressure pipe and the drain and a low pressure impulse pipe between the drain pipe and the low pressure pipe, the first flow meter with the corresponding shut-off valve in series in the first impulse pipe, and the second flow meter with the corresponding shut-off valve in series in the second impulse pipe.

The first and second impulse tubes can be connected to the drainage tube at one point, while the device may further comprise a cross and a fourth shutoff valve, the crosspiece being pneumatically connected to the output of the shutoff valve of the drainage tube, with the output of the first flow meter, with the input of the second flow meter and with the input the fourth drainage valve communicating with the outlet to the atmosphere.

Flowmeters are flow meters.

As flow meters, vortex meters can be used.

The invention is illustrated in the drawing, which shows a diagram of a device for implementing a method of measuring gas flow through an unpressurized shutter of a closed ball valve ZRA MT.

In the drawing, at position 1, a ball valve ZRA with an unpressurized closed valve having seals 2 and 3 is shown. To the left and right of the valve 1, respectively, under the positions 4 and 5, MT 6 low and high pressure pipelines are shown.

There are three pressure gauges 7, 8 and 9 (static gas pressure gauges), respectively connected to the high pressure pipe 4, the on-cock cavity of the ball valve 1 and to the low pressure pipe 5.

To these elements are also connected respectively a pulse tube 10 of high pressure, a drainage tube 11 and a pulse tube 12 of low pressure. Each of these tubes contains shut-off valves 13, 14 and 15.

The pulse tubes 10 and 12 of high and low pressure, in addition, contain flow meters 16 and 17 (for example, vortex).

The output of the flow meter 16, the drain pipe 11 (after the shutoff valve 14) and the input of the flow meter 17 are pneumatically connected to each other by a spider 18. At the same time, a shutoff valve 19 connected to the atmosphere is connected to the fourth output of the spider 18.

A method of measuring gas flow through an unpressurized shutter of a closed ball valve ZRA MT 6 is implemented in a device of the same purpose as follows.

In the operational state of ZRA, all shut-off valves 13, 14, 15 and 19 are in the closed position.

When testing the seal 2, located between the high-pressure pipe 4 and the on-tap cavity of the ball valve 1, the shut-off valves 14 and 15 are opened. Gas from the high-pressure region rushes into the low-pressure region into the valve cavity through the test seal 2, passing through the crosspiece 18 and flow flow meter 17 (the gas path is indicated by a dashed arrow).

In the steady-state gas outflow mode, when the pressures in the high-pressure pipeline 4 and the on-cock cavity of the valve 1, measured by pressure gauges 7 and 8, are equalized, the readings of the flow meter 17, previously calibrated in units of gas flow, are taken. Then, all the shut-off valves are closed.

Measured by the flow meter 17, the gas flow is taken as the leakage of the seal 2 ZRA.

When testing the seal 3 located between the in-crane cavity of the valve 1 and the low-pressure pipe 5, the shut-off valves 13 and 14 are opened. Gas (in the direction of the solid arrow) rushes from the high-pressure region in the valve cavity to the low-pressure region through the flow meter 16, crosspiece 18 and leaky seal 3.

In the steady state gas outflow, when the pressure in the on-crane cavity of the valve 1 and the low-pressure pipe 5, measured by pressure gauges 8 and 9, are equalized, the readings of the flow meter 16, also calibrated in units of gas flow, are taken.

The obtained flow rates are taken as the amount of leakage of the seal 3 ZRA.

The sequence of tests for the tightness of the ZRA seals (which of the seals we test first, and which second) does not matter when implementing the method.

Before each measurement of the gas flow through the seals 2, 3 ZRA it is possible by opening the shut-off valves 14, 19 to clean the crane cavity from the transported gas by its release into the atmosphere. Then the shut-off valves 14, 19 are closed.

Thus, the practical implementation of the method and device allows to separately measure gas leaks through each valve seal. Moreover, the measurements are carried out in a direct way when using calibrated flow meters, which increases the accuracy and reliability of the tests of the air defense system in comparison with the known method and device.

Claims (7)

1. The method of measuring gas flow through an unpressurized shutter of a closed ball valve of the shut-off and control valves of the main pipeline, which consists in connecting a drain pipe to the valve cavity and measuring static pressures in the high and low pressure pipelines, as well as in the cavity of the ball valve, characterized in that a high pressure pipeline is additionally connected with a drain pipe and, in steady state, the gas flow rate is measured in it through the seal between the valve cavity and the low pressure pipe I, and then connect the low pressure pipeline with the subsequent measurement in the drainage tube of the gas flow through the seal between the high pressure pipeline and the cavity of the ball valve. 2. The method according to claim 1, characterized in that the steady-state time when measuring gas flow rates through ball valve seals is determined respectively by the equality of static pressures in the valve cavity and low pressure pipe and in the valve cavity and high pressure pipe. 3. A device for measuring gas flow through an unpressurized shutter of a closed ball valve of the shutoff and control valves of the main pipeline, comprising a drainage tube with a shutoff valve connected to the valve cavity and three pressure gauges connected to the high and low pressure pipelines, as well as to the cavity of the ball valve main pipeline, characterized in that it further comprises pulse tubes of high and low pressure, the first and second flow meters and a third shut-off valve, while the pulse tr a high pressure line is installed between the high pressure pipe and the drain pipe, and a low pressure pulse pipe is between the drain pipe and the low pressure pipe, the first flow meter with a corresponding shut-off valve installed in series in the first pulse pipe, and the second flow meter with the corresponding shut-off valve installed in series second impulse tube. 4. The device according to claim 3, characterized in that the first and second impulse tubes are connected to the drainage tube at one point. 5. The device according to claim 4, characterized in that it further comprises a cross and a fourth shut-off valve, wherein the cross is pneumatically connected to the output of the shut-off valve of the drain pipe, with the output of the first flow meter, with the input of the second flow meter and with the input of the fourth drain valve, communicating with the output with the atmosphere. 6. The device according to claim 3, characterized in that flow meters are used as flow meters. 7. The device according to claim 6, characterized in that vortex flowmeters are used as flow meters.

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