RU184543U1 - DEVICE FOR CHECKING THE PRESSURE OF THE BEGINNING OF OPENING OF RELIEF SPRING SAFETY VALVES WITH MANUAL EXPLOSION - Google Patents

Abstract

The invention relates to the field of the gas industry, in particular, to a device for checking the start pressure of a safety valve discharge spring with manual blasting, which allows for such a test without dismantling the equipment, and can be used to safely operate a safety valve discharge spring installed in gas industry facilities. . A device for checking the pressure of the beginning of the opening of the relief spring of the safety valve with manual detonation consists of axis 1, cap 2, plug 3, body 4, spring 5, rod 6, spool 7, seat 8, lever 9 for manual detonation on axis 1, mechanism (on Fig. is not indicated), including a torque wrench 10 and an adapter (not shown in Fig.), while the rod 6 with a spring 5 is installed in the housing 4, in the upper part of the rod 6 under the cap 2 there is a plug 3 with an axis 1 and a manual lever 9 undermining, and in the lower part of the stem 6 mounted spool 7 with a saddle 8, while on the axis 1 p a lever 9 for manually detonating the safety valve has a mechanism installed, including a torque wrench 10 and an adapter that is removable, since during the operation of the reset spring safety valves (SPPC) at gas distribution stations (GDS), it is necessary to periodically check the valve setting pressure, according to normative documents, the setting of the setting pressure should be carried out and checked on a special stand, however, in the conditions of operation of the SPPK it does not always exist I have the opportunity, however, operating staff should always be sure of the safety valve setting. The SPPC on the gas distribution system must be equipped with a mechanism including a torque wrench 10 and an adapter, which will allow without any intervention in the design of the safety valve or dismantling of its parts to check the pressure at which the safety valve starts to open when the safety valve is manually opened. The technical result, which can be obtained using the proposed utility model, is to simplify the design and increase the reliability of the device for checking the opening pressure of the safety valve direct-acting with manual blasting. 3 ill., 2 tablets

Description

The technical field to which the utility model relates.

The invention relates to the field of the gas industry, in particular, to a device for checking the start pressure of the safety valve discharge spring with manual blasting, which allows for such a test without dismantling the equipment and can be used for safe operation of the safety valve discharge spring installed in gas industry facilities .

State of the art

A device for checking the pressure of the beginning of opening the dump spring safety valves with manual blasting, comprising a housing in which a rod with a spring is installed, a lever of manual blasting mounted on the axis of the lever, spool, seat (see "Device for checking the pressure of the beginning of opening of the dump spring safety Valves ”, Guidance document WFD 39-1.10-069-2002).

The disadvantage of this device is the insufficient accuracy of the correct setting of the safety valves, since during the operation of the reset spring safety valves (SPPK) at gas distribution stations (GDS), it is necessary to periodically check the valve setting pressure, while according to regulatory documents, the setting pressure must be set and checked at a special stand, however, in the conditions of operation of the SPPK, this possibility does not always exist, nevertheless operation In personnel should always be sure of the safety valve setting.

A device for testing safety valves comprising a pneumatic actuator for moving a valve stem, a pneumatic actuator control unit, a kinematic element for connecting a valve stem to a pneumatic actuator, a mounting bracket for installing a pneumatic actuator and a kinematic element on the valve, valve position sensors and means for displaying information and measuring valve actuation force, this control unit of the pneumatic actuator is made with a pneumatic system of pneumatic valves and adjustable throttle remote electromagnetic control associated transmission line control signal from the valve position sensors and the information display means, and measuring the force of the valve actuation.

In the device, the means of displaying information and measuring the valve actuation force is made with the terminal of remote input-output information.

In the device, the kinematic element is made in the form of a lever, while the mounting bracket is made cantilever and with a hinged support of the lever.

In the device, the lever arm connected to the valve stem has the form of a fork (see US Pat. RU No. 35464 class G21C 17 / 06.10.01. 2004).

The disadvantage of this device is its complex design, high cost, during operation, partial disassembly of the safety valve is required and, due to design features, the use of a limited number of types of safety valves.

The closest in technical essence and the achieved positive effect and accepted by the authors as a prototype is a device for checking the operability of safety valves without dismantling them from equipment, containing a mechanical part as part of the supporting structure for mounting to the tested safety valve (IPC), a moving part as part of a moving screw with a worm pair and an electric drive as part of an electric motor and gearbox, as well as an electronic part as part of a control circuit, sensors and measuring transformers ovateley and pressure forces as well as the processor, wherein the instrument introduced and are connected to the inputs of the drive control circuit sensors extreme positions of the driving screw, and the program processor for calculating the opening pressure of introduced operation of calculating the average active diameter D _cp. IPC saddles, while the latter contains a body with an upper stop of the spring of the rod, which is equipped with a plumb beneath the saddle of the IPC, and the lower stop of the spring is fixed to the rod, which ensures that the suspension is _clamped to the saddle with a force F of _spring elasticity, and to the power output of the electric drive control circuit an electric motor is connected.

In the device, the control circuit of the electric drive, pressure and force measuring transducers, as well as the processor and control elements of the device are made in the form of a remote unit and are connected to the sensors and the electric drive located in the mechanical part through a cable up to 30 m or more in length.

In the device, when any of the sensors of the extreme positions of the propeller is triggered, the propeller is automatically returned to its initial (zero) position.

In the device, the extreme position sensors of the propeller are made inductive (see US Pat. RU No. 84,980, class G01L 1/00, publ. July 20, 2009).

The disadvantage of this device is that the control circuit, the mechanical part of the device, pressure and force transducers, have a very complex structure, high cost, and low operational properties: the need for partial disassembly of the safety valve and the complexity of mounting the supporting structure on the safety valve, and also the presence of an electric drive installed directly on the test valve excludes the possibility of using this device in explosive atmospheres meals.

Utility Model Disclosure

The objective of the proposed utility model is the development of a device for checking the start pressure of the safety valve relief valve opening with manual blasting, having a simplification of the design and improving the reliability of the device for checking the opening start pressure, direct-acting safety valve with manual blasting.

The technical result, which can be obtained using the proposed utility model, is to simplify the design and increase the reliability of the device for checking the opening pressure, direct-acting safety valve with manual blasting.

The technical result is achieved using a device for checking the start pressure of the opening of the safety valve relief valve spring with manual blasting, made in the form of a removable mechanism, including a torque wrench and an adapter, which is configured to install the mechanism on the axis of the manual valve blast lever of the safety valve, and with the possibility of measuring and fixing the moment at which the axis of the manual blast lever rotates to a minimum angle.

Thus, the task and the specified technical result are achieved in that the device for checking the pressure of the opening of the safety valves additionally contains a digital torque wrench mounted on the axis of the lever for manually detonating the safety valve, instead of the standard lever, through the adapter, while measuring and fixing the moment, where the torque wrench is rotated by a minimum angle and, using the formula for converting the moment into force and pressure, depending on the cross-sectional area of the metal who seal the safety valve, it is possible with sufficient accuracy to obtain the pressure of the opening of the safety valve. The calculation is carried out according to the following formula:

where r is the distance between the axis 1 of the lever 9 of the manual blasting and the stem 6 of the safety valve, m;

Rno - pressure of the beginning of valve opening, Pa;

Рр - working pressure in the pipeline, Pa;

Sсp - the area of the average diameter of the seal m ² .

A limitation of the application of the described utility model is the requirement for the presence of pressure at the installation site of the safety valves at least 80% of the setting pressure.

Brief description of drawings and other materials

In Fig 1. given a device for checking the pressure of the beginning of the opening of the reset spring safety valves with manual blasting, safety valve, General view in section.

In FIG. 2, also, a manual detonation lever on the lever axis in a section.

In FIG. 3, too, a mechanism including a torque wrench and an adapter, general view.

In FIG. 4, also, the use of a device for checking the pressure of the start of opening of the reset spring safety valves on the example of SPPK-4R-50-16, prototype, table 1.

In FIG. 5, calculation of the possible range of moments for all applicable types of SPPK, table 2.

Utility Model Implementation

A device for checking the pressure of the beginning of the opening of the relief spring of the safety valve with manual blasting, consists of axis 1, cap 2, plug 3, body 4, spring 5, rod 6, spool 7, seat 8, lever 9 for manual detonation on axis 1, mechanism ( in Fig. is not indicated), including a torque wrench 10 and an adapter (not shown in Fig.), while the stem 6 with spring 5 is installed in the housing 4, in the upper part of the stem 6, under the cap 2, a plug 3 with axis 1 and lever 9 manual detonation, and in the lower part of the stem 6 mounted spool 7 with a seat 8, while on the axis 1 lever 9 for manually detonating the safety valve, a mechanism is installed that includes a torque wrench 10 and an adapter that is removable, and since during the operation of the reset spring safety valves (SPPK) at gas distribution stations (GDS), it is necessary to periodically check the valve setting pressure , according to normative documents, the setting of the setting pressure should be carried out and checked on a special stand, however, in the operating conditions of the SPPK it does not always exist Which opportunity, however, operating staff should always be sure of the safety valve setting. The SPPC on the gas distribution system must be equipped with a mechanism including a torque wrench 10 and an adapter, which will allow, without any intervention in the design of the safety valve or dismantling of its parts, to check the pressure of the opening of the safety valve discharge spring with manual blasting.

A device for checking the pressure of the beginning of the opening of the discharge spring of the safety valve with manual blasting is operated as follows.

As you know, when calculating the safety valve, the necessary force of the spring 5 is installed, installed on the stem 6, located in the housing 4. In this case, for the metal seal, the seat 8 - spool 7 (see Fig. 1), use the well-known formula:

where Fпp - spring force 5;

Rn - pressure settings;

Sav - the area of the average diameter of the seal;

1,05-5-1,07 - recommended by the standard values of the coefficients at Рн, determining Рно (pressure of the beginning of opening).

Thus, the force of the spring 5 depends on the setting pressure of the safety valve and the area of the seal along the average diameter of the seat 8.

From the formula (1) it is seen that the force of the spring 5 is 5-7% higher than the force acting on the spool 7, in the presence of the setting pressure Рн. Then you can write:

where Rno is the pressure at which the safety valve begins to open.

Guiding documents (for example, WFD 39-1.10-069-2002) set the upper value of the working pressure Рр + 12%, above which the safety valve should automatically open and relieve pressure in the gas pipeline (not shown in Fig.) To the working one. With this in mind, you can write:

Whence it follows that if the force created by the working pressure is increased by 12%, then the safety valve will begin to open. On the other hand, if a safety valve starts to open when 12% of the force is added at operating pressure, it is set correctly. Therefore, by measuring the force when the safety valve is opened by the lever 9 for manual blasting (in the presence of working pressure in the pipeline), it is possible to check the pressure at which the safety valve starts to open. To do this, instead of the lever 9 for manual detonation, it is necessary to install a torque wrench 10 through the adapter, select the free travel of the lever 9 for manual detonation and measure the force at which the lever 9 makes a minimum rotation around axis 1. With the correct setting of the safety valve, this force should be 12%, the forces created by working pressure.

For practical use, it is advisable to use a torque wrench 10 with digital indication, an audible alarm of the set moment, entered in the register of measuring instruments and authorized by an authorized organization. Pressure measurement is carried out using a staff attorney or calibrated pressure gauge mounted on the pipeline.

To recalculate the moment measured by a torque wrench 10 in force, measure the distance g between the axis 1 of the lever 9 of the manual blasting and the stem 6 of the safety valve (see in Fig. 2). But from the practical side, it is more convenient to calculate the necessary moment to reach the beginning of the discovery and compare it with the measured one.

An example of a specific application of a prototype device for checking the pressure of the start of opening of the reset spring safety valve with manual blasting on the example of SPPK-4P-50-16.

This safety valve is installed on the gas pipeline (not shown in FIG.), In which the operating pressure is 1.0 MPa (in practice, the pressure measured by the pressure gauge must be used). The opening pressure of this pressure relief valve will be 1.12 MPa. Calculate the force of the spring 5 with this setting of the safety valve according to the formula (2)

The force created by the working (measured pressure gauge) pressure is

Missing force to balance spring 5

1046.5-934.3 = 112.2 N.

Considering that in this safety valve, the distance between the axis 1 of the rod 6 and the axis 1 of the manual blasting lever 9 is 34.0 mm, the moment M is determined at which, relative to the axis 1 of the manual blasting lever 9, the safety valve starts to open:

M = 112.2 × 0.034 = 3.81 Nm To check the pressure of the start of opening of the reset spring

the safety valve set the calculated value on the torque wrench 10 (see Fig. C), by means of the adapter, install the torque wrench 10 on the axis 1 of the lever 9 manual blasting. Turning, select the free movement of the mechanism, including the torque wrench 10 and the adapter, manual blasting, then when the set torque is reached, the sound of the torque wrench 10 is heard, while the manual blast lever 9 should turn a small angle, which means the opening of the safety valve, if when the sound signal is reached, the manual detonation lever 9 does not budge, the safety valve setting is too high, otherwise, if the manual detonation lever 9 is turned before the audible signal, safety valve trimming is underestimated. To calculate the moment, you can use the formula:

where: r is the distance between the axis 1 of the lever 9 of the manual blasting and the stem 6 of the safety valve, m;

Rno - pressure of the beginning of valve opening, Pa;

Рр - working pressure in the pipeline, Pa;

Scp is the area of the average diameter of the seal m ² ;

and for each type of safety valve, its structural elements are used, for convenience in work, table 1 of the formulas for the applied types of SPPK is compiled. The pressure value in the formulas is given in pascals.

To determine the possible range of moments, consider the conditions of the above example of calculating the moment for all applicable types of SPPK. The data are presented in table 2.

At the same time, if all standard sizes of SPPK are used in the operation service, then to create the necessary moments, the operation service must have at least two torque wrenches with ranges: 0-20 Nm and 0-100 Nm. Thus, the measurement accuracy can be improved, and at the same time, the pressure check of the safety valves of any types and manufacturers can be checked by dismantling the standard cap 2 with the lever 9 for manual blasting and replacing it with a pre-fabricated lever mechanism with a strict size r. You can also check the safety valves without the mechanism of manual blasting, if only the length of the stem 6 allows you to fix the clamping sleeve (Fig. Not shown). The accuracy of the opening pressure test depends on several parameters. In this example, the accuracy of measuring pressure with a manometer is usually 1.5%, the accuracy of a torque wrench is 10, good models have 2%, the accuracy of manufacturing a saddle is 8, (Sep area - 1.5%), the measured size r - 4%. For simplicity, the weight of the spool 7 and the stem 6 and the influence of temperature can be neglected by taking measurements at a temperature close to normal. The total standard error of the measurement will not exceed 5%.

The proposed utility model in comparison with the prototype and other well-known technical solutions has the following advantages:

- simplification of the design;

- low cost with sufficient accuracy of pressure measurement of the opening of the safety valves;

- ease of use, no need to disassemble valve parts.

Claims (1)

A device for checking the pressure of the beginning of the opening of the discharge spring of the safety valve with manual blasting, made in the form of a removable mechanism, including a torque wrench and an adapter, which is made with the possibility of installing the mechanism on the axis of the lever for manual blasting of the safety valve, and with the possibility of measuring and fixing the moment at which the axis of the manual detonation lever rotates to a minimum angle.

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