Measuring nipple with pierceable seal

Abstract

FIELD: measurement technology.SUBSTANCE: devices for periodic pressure sampling and temperature measurement in heating and water supply pipeline systems. The measuring nipple contains a hollow body with connecting elements and a cylindrical seal made of elastically deformable material placed in it. The internal cavity of the housing is stepped and consists of two parts of different diameters: a larger one on the side where the seal is installed, and a smaller one. The seal height is 0.5–0.7 of the length of the cavity part with a large diameter, and its outer diameter exceeds the diameter of the specified cavity part. In the end surfaces of the seal, along its longitudinal axis, there are circular recesses. On the side where the seal is installed, a locking sleeve is rigidly fixed in the housing, the internal diameter of which is equal to the diameter of the recesses in the end surface of the seal.EFFECT: increasing the service life and the number of measurement cycles while maintaining the tightness of the device.2 cl, 3 dwg

Description

[0001] The technical solution relates to measuring equipment and can be used as elements of devices for measuring and regulating the pressure and / or temperature of a liquid, for example, in a heating system or in a hot / cold water supply system.

[0002] To regulate fluid flow in various pipeline systems, control valves of various designs are commonly used. To measure the pressure of the fluid passing through the valves in specific zones, measuring nipples with built-in pressure sensors or connected to external pressure sensors are typically used.

[0003] A known example is a valve with a control function (see RU Patent No. 2444665, IPC F16K1 / 52, F16K1 / 46, F24D19 / 10, published March 10, 2012), containing measuring nipples installed and secured in its body, by means of which the current pressure drop in the valve, from its inlet side to its outlet side, can be measured and the current flow rate through the valve can be measured and known accordingly. The design of each nipple assumes the presence of a movable piston, which, when the plug is removed and a pressure sensor is connected, under the action of fluid pressure from below on the piston, moves, pressing on the pressure sensor.

[0004] This design allows for periodic pressure measurement in a given area of ​​the valve, but is technologically complex, since it requires high precision mating between the side surface of the piston and the inner surface of the nipple body to ensure tightness, on the one hand, and the ability to move with minimal friction of the piston in the body of the measuring nipple, on the other hand.

[0005] These are known measuring nipples used in control valves, the design of which does not include moving elements, the formation of a channel for measuring pressure in them is ensured by installing a hermetically sealed pierceable seal in them.

[0006] A measuring nipple with a pierceable seal, fixed in a measuring needle with a check valve function, is known as the closest analogue (see patent RU No. 2550715, IPC G01L 19 / 00, F16L 29 / 02, F16L 37 / 42, F16K 15 / 00, published on 10.05.2015). The known measuring nipple contains a hollow body with a round internal cross-section of the same diameter, at the ends of which means for connecting to external devices are made, a cylindrical seal made of an elastic deformable material is installed and fixed inside the body.

[0007] To perform its function, the measuring nipple is installed and secured at one end in the body of the control valve, ensuring a tight seal within the specified pressure and / or temperature range. A known measuring needle is secured to the other end of the measuring nipple, and the nipple seal is pierced (this causes radial deformation of the seal—compression from the longitudinal axis of the nipple to the inner surface of its body in cross-sections) to connect the interior of the specified zone of the control valve to the measuring sensor through the needle's internal channel. Measurements of the desired physical characteristic (pressure or temperature) are then performed. After the appropriate measurements are completed, the measuring needle is disconnected. The elastically deformed seal of the measuring nipple, by restoring its shape, again closes the connection channel between the interior of the specified zone of the valve and the exterior.If necessary, an additional plug is installed at the end of the measuring nipple from which the measuring needle was disconnected to increase the reliability of the seal.

[0008] A well-known measuring nipple provides the possibility of periodic measurement of parameters in a given zone of the control valve without its installation / dismantling operations, but has certain disadvantages.

[0009] In particular, with each subsequent puncture for measurements, the likelihood of deterioration of its functionality (integrity, strength, restoration of the specified geometry) increases. This occurs because, when inserting a needle into the seal, its deviation from the longitudinal axis of the seal (even small) can lead to punctures into a new hole. Gradually, the number of such holes (in practice, 10 or more) leads to seal failure or destruction.

[0010] The technical result of the claimed solution is an increase in the service life of the measuring nipple, expressed in the possibility of a greater number of measurements, while maintaining the specified tightness parameters, without the need to replace it or replace its structural elements.

[0011] The technical result is achieved in that the measuring nipple with a pierceable seal contains a hollow body with connecting elements made at its ends and a cylindrical seal made of an elastically deformable material installed inside the body, wherein the internal cavity of the body consists of two cylindrical parts with a stepwise variable cross-section diameter, a larger one on the side of the seal installation, a smaller one on the reverse side, the height of the cylindrical seal is from 0.5 to 0.7 of the length of the part of the internal cavity of the body with a larger diameter, in the end surfaces of the cylindrical seal along its longitudinal axis there are recesses of a circular cross-section, and the outer diameter of the cylindrical seal slightly exceeds the larger diameter of the internal cavity, in addition, on the outer side of the internal part of the cavity with a large diameter under the cylindrical seal a locking sleeve is installed and rigidly fixed,the internal diameter of which is equal to the diameters of the recesses in the end surface of the cylindrical seal.

[0012] In addition, the cylindrical seal of the nipple may contain a starting puncture made in the factory along the longitudinal axis.

[0013] The claimed technical solution is explained by drawings, where Fig. 1 schematically shows a longitudinal axial section of the measuring nipple, and Fig. 2, Fig. 3 - the principle of its operation in the valve.

[0014] The schematic images shown in the drawings are presented solely to explain the essence of the technical solution; the specific implementation of the elements of the claimed device that do not affect the achievement of the technical result, for example, the shape of the outer surface of the body of the measuring nipple, can be implemented by any known options.

[0015] A measuring nipple with a pierceable seal comprises a hollow body 1 with a part 2 of the internal cavity with a smaller diameter (d3), a part 4 of the internal cavity with a larger diameter (d5) and elements 6 for connecting the body, a cylindrical seal 7 with recesses 8, a locking sleeve 9. The measuring nipple may additionally contain a plug 10.

[0016] The drawings also show a piercing needle 11, a control valve 12, a measuring device 13 with corresponding sensors (pressure, temperature).

[0017] In addition, the description of this application includes the following designations characterizing the geometric parameters of the device elements:

[0018] - length of body of 1 measuring nipple - L;

[0019] - length of part 2 of the internal cavity - l2;

[0020] - length of part 4 of the internal cavity - l4;

[0021] - cylindrical seal height 7 - h у ;

[0022] - height of the fixing sleeve 9 - hвт ;

[0023] - diameter of part 2 of the internal cavity - d3;

[0024] - diameter of part 4 of the internal cavity - d5;

[0025] - outer diameter of cylindrical seal 7 - d уп ;

[0026] - diameter of recesses 8 - d уг ;

[0027] - inner diameter of the locking sleeve 9 - d вт .

[0028] The assembly of the claimed measuring nipple is carried out as follows.

[0029] Cylindrical seal 7 is inserted into housing 1 from the side of part 4 of its internal cavity and pressed into it to a depth corresponding to the total height h у + h вт . Since d упslightly exceeds d5, the installation of seal 7 is carried out “tightly”, while in the text of this application the numerical value of the term: “slightly exceeds” can vary in the range from 0.1% to 1% and in each specific case depends on the choice of material for seal 7, which, in turn, is selected based on the required operational characteristics of the device (such as the modulus of elasticity, elastic limit, operating temperature range, etc.).

[0030] Next, from the same side, insert the locking sleeve 9, press it until it is completely immersed in part 4 of the internal cavity of the housing 1 and firmly fix it in this position using any known method.

[0031] After this, the device is installed and secured to the specified area of ​​the pipeline system using the body connection element 6 on the side of part 4, ensuring the required tightness. If necessary, between measurements, plug 10 is installed and secured to the device on the side of part 2 to ensure additional tightness.

[0032] The elements 6 of the housing connection within the framework of the claimed solution are not specified and may represent various known solutions, for example, fittings, couplings, various types of threads, etc.

[0033] The operation of the claimed device is carried out as follows.

[0034] If it is necessary to measure the corresponding parameters in a given area of ​​the pipeline, a measuring device 13, containing a piercing needle 11, is installed and secured to the body 1 of the measuring nipple on the side of the outlet of part 2 of its internal cavity using the body connection element 6, ensuring the tightness of the connection. In the case where a plug 10 is installed on the device, it is first removed.

[0035] By moving the needle 11 (hollow inside) inside the housing 1, a through puncture of the seal 7 is produced, providing a channel for the passage of the measured medium from a given zone of the pipeline to the corresponding sensors of the measuring device 13, after which the required parameters of the medium in a given zone are directly measured. In this case, the seal 7, under the action of the force from the needle 11 during the puncture, is deformed in the radial and, partially, axial direction (it is compressed in the direction of the inner surface of the housing 1, slightly elongated along the longitudinal axis of its internal cavity). Radial displacement is impossible due to the mating of the seal 7 with the inner surface of the housing 1, and axial displacements are limited, on one hand, by the fixing sleeve 9, on the other hand, by the surface of the "step" of the change in the diameter of parts 2 and 4 of the internal cavity of the housing 1, respectively.

[0036] After the appropriate measurements are taken, needle 11 is removed from seal 7, and device 13 is disconnected from the measuring nipple. Seal 7 then returns to its original size and shape, hermetically sealing the specified pipeline zone from the outside. After device 13 is removed from the measuring nipple, it continues to ensure the tightness of the pipeline system. If necessary, plug 10 is reinstalled at its outlet from part 2 until further measurements are taken.

[0037] The design of the internal cavity of the housing 1, consisting of two cylindrical parts 2 and 4 with stepwise variable diameters 3 and 5 of the sections, respectively, in combination with the presence of recesses 8 in the seal 7 ensures the minimization of axial deviations of the needle 11 during piercing, the geometric dimensions of the seal 7 (the ratio of its height to the length of part 4 of the internal cavity of the housing 1 in the range from 0.5 to 0.7) ensure the distribution of the deformation into radial and axial components, thereby reducing its limiting dimensions and, as a consequence, minimizing damage to the homogeneity of the seal 7, and the locking sleeve 9 does not allow the seal 7 to be squeezed out of the cavity of the housing 1 and, at the same time, additionally minimizes possible deviations of the needle 11 after piercing and when moving in the opposite direction (withdrawal from the seal 7).

[0038] Taken together, the above-described features ensure an increase in the service life of the measuring nipple and reduce the possibility of its damage without complicating the design.

[0039] A series of tests have shown that the following ratios between the corresponding dimensions of the elements of the claimed device are the most optimal for production and operation:

[0040] - h у / l4= 0.5 - 0.7;

[0041] - l4 / l2= 1.8 - 2.3;

[0042] - L / l4= 1.3 - 1.7;

[0043] - h у / h вт = 3.0 - 5.0;

[0044] - h у / d уп = 2.5 - 3.0;

[0045] - h вт / d вт = 0.6 - 1.0;

[0046] - d уп / d уг = 1.4 - 2.0;

[0047] - d5 / d3= 1.4 - 2.0.

[0048] Shifting the ratios below the test ranges significantly increases the likelihood of the seal entry / exit points deviating from the axis. Shifting them above the test ranges significantly increases the overall dimensions of the measuring nipples, complicating their production and operation.

[0049] The claimed technical solution ensures an increase in the service life of a measuring nipple with a pierceable seal and reduces the risk of its damage / failure without complicating its design.

Claims

1. A measuring nipple with a pierceable seal, comprising a hollow body with connecting elements formed at its ends and a cylindrical seal made of an elastically deformable material installed inside the body, characterized in that the internal cavity of the body consists of two cylindrical parts with a stepwise variable cross-sectional diameter, a larger one on the side where the seal is installed, a smaller one on the reverse side, the height of the cylindrical seal is from 0.5 to 0.7 of the length of the part of the internal cavity of the body with a larger diameter, in the end surfaces of the cylindrical seal along its longitudinal axis there are recesses of a circular cross-section, and the outer diameter of the cylindrical seal slightly exceeds the larger diameter of the internal cavity, in addition, on the outer side of the internal part of the cavity with a large diameter under the cylindrical seal a locking sleeve is installed and rigidly fixed,the internal diameter of which is equal to the diameters of the recesses in the end surface of the cylindrical seal.

2. A measuring nipple with a pierceable seal according to paragraph 1, characterized in that the cylindrical seal of the nipple contains a starting puncture made along the longitudinal axis under factory conditions.

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