RU2611538C2 - Bubble-tight valve for sampling container - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to a shut-off valve used for gaseous media and can be used, in particular, in sampling containers. The bubble-tight valve comprises a base 1, a housing 2, at least four sealing rings 5, 6, 7 and 8 of resilient polymeric material and spindle 3 with a slide valve 3a. Spindle 3 also serves as a handle for control valve 3c to control gas flows and as a channel 3b to the gas flows. On spindle 3 to slide valve 3a, two slots 3d and 3e for two sealing rings 7 and 8. Slots 3d and 3e and parts 1a and 2a of base 1 and valve housing 2, adjacent to which there are sealing rings 7 and 8, spindles 3 with slide valve 3a in the open and closed valve position, have a shape corresponding to the shape of the sealing rings. Between slots 3d and 3e on spindle 3, there is is thread 3g, whereby base 1 is connected to spindle 3 and slide valve 3a is moved by rotation of handle 3c of the valve. Channel for gas flows 3b within the valve ends with a perpendicular to its axis hole 3e through which gas flows pass into (from) the channel in the spindle part where the threaded is located. In slots 3a and 3d, there are arranged sealing rings 7 and 8 made of elastic polymer material with low gas permeability, providing the opportunity of "washing" with the gas carrier or gas sampled into a sampling container of "dead" valve volumes. Two other sealing rings 5 and 6 made of polymeric elastic material are placed between base 1 and valve housing 2 on either side of wall 4 of the sampling container.

EFFECT: increased valve gas tightness of the sampling container and the possibility of washing with gas carrier or gas sampled into a sampling container of "dead" valve volumes of bubble-tight valve, increased service life of the valve and the sampling container used with it.

3 cl, 5 dwg

Description

FIELD OF THE INVENTION

The present device relates to valves used for gaseous media, and can be used, in particular, in sampling tanks.

State of the art

It is known to use a valve providing access to a gas sampling container with a flexible shell (patent US 7219874 “Access fitting for gas sampling bag”), having a base and a cover, in the lower part of which a groove is made. In the specified groove is a tape made of a material similar or the same from which a flexible shell of the sampling container is made. The section of the said tape, located opposite the channel for gas flows, acts as a barrier that does not allow the gas sample to leave the sampling tank.

In this solution, said tape is pierced by a syringe needle through a channel for gas flows at each sampling, and after completion of the sampling procedure, the tape is moved so far that the hole made by the syringe needle extends beyond the gas channel. In this way, the reusable use of the described valve of the sampling vessel with a flexible shell is ensured.

The disadvantages of this solution are a sufficiently high gas permeability of the node in which the tape slides; inability to take a sample from a sampling container without using a needle; the inability to "flush" the "dead" valve volumes; insufficient reliability of the connection of the base and valve cover in terms of ensuring gas tightness; bulky valve design, in particular its element, placed inside the sampling tank.

It is known to use a valve of a sampling tank for gas with a flexible shell (patent CA 2668849 “Gas sample bag with fitting and valve”), having a molded plastic fitting and a cap with thread, a silicone partition, a hollow rod in the form of a tube plugged on one side, inserted inside the valve channel and having a hole in the side wall near the muffled side of the stem.

There are two possible versions of this valve: for working with a gas sample using a syringe with a needle and without using a needle and syringe. In the first case, between the cap and the fitting there is a silicone partition acting as a barrier preventing the gas sample from escaping from the sampling tank. This septum is designed to pierce a syringe through a hole in the valve cap when sampling. In the second case, the stem with the hole serves as a valve control element for the gas flow. The outer diameter of the rod is selected in such a way that it provides tight movement in the fitting channel. By moving the stem along the fitting until the hole in the side wall of the stem overlaps, you can control the flow of gas passing through the valve.

The disadvantages of this solution are the increasing gas permeability of the node in which the rod moves, due to the abrasion of the rubbing surfaces when dust enters the rod; the inability to use the sampling container without the use of a needle if the rod is deformed during operation; the inability to "flush" the "dead" valve volumes; sufficiently high gas permeability of the silicone septum after piercing it with a syringe needle.

The closest technical solution to the proposed invention is proposed in the patent CN 201514346 U "Gas sampling bag" device. The valve of this device is fixed on the sampling vessel by a threaded connection and supports the possibility of using the sampling vessel using both a needle and a syringe, and without using a needle.

In this invention, the rotation of the valve cover actuates a rod fixed in the valve body using a plastic o-ring, the inner end of which is made in the form of a tapering hollow tube, forming together with the counterpart of the body a needle valve. When the valve cover rotates in one direction, the stem moves down and the inner end of the stem closes the channel for gas flow, and when the valve cover rotates in the other direction, the stem moves up and the inner end of the stem opens the channel for gas flow.

The disadvantages of this prototype are the need for accurate fitting of the elements of the needle valve assembly to ensure high gas tightness of the contact connection of the tapering hollow tube and the reciprocal part of the housing in the closed position of the valve; the inability to "flush" the "dead" valve volumes; insufficient reliability of the connection of the valve and the wall of the sampling tank, both in terms of mechanical integrity and in terms of ensuring gas tightness; a sufficiently high gas permeability of the silicone septum intended for sampling using a needle and syringe after it is pierced by a needle.

Disclosure of invention

The problem to which the present invention is directed, is to achieve a technical result, which consists in increasing the valve gas tightness for a sampling tank and providing the possibility of “flushing” with a carrier gas or gas of “dead” gas tight valve volumes taken into a sampling tank, as well as in increasing the service life valve and, therefore, the sampling tank used with it.

The specified technical result is achieved in that the valve comprises a base, a housing, at least four o-rings of polymer elastic material and a spindle with a spool, and the spindle also acts as a valve handle for controlling gas flows and the role of a channel for gas flows. The spool is moved to open and close the valve by rotating the valve handle. In this case, the base and valve body are connected by snap-fit, forming an inseparable reliable connection.

Thus, the distinguishing features of the invention is that two grooves for two o-rings are formed on the spindle with the spool, said grooves and parts of the base and valve body to which the sealing rings of the spindle with the spool in the open and closed position of the valve are adjacent, have the form corresponding to the shape of these o-rings, between the said grooves on the spindle there is a thread by means of which the base and the spindle are connected and the spool moves when the arms rotate and the valve. The channel for gas flows inside the valve ends with an opening perpendicular to its axis through which gas flows pass into (from) the channel in that part of the spindle where the thread is located. O-rings made of polymer elastic material with low gas permeability are located in the said grooves, which make it possible to “rinse” with carrier gas or gas of “dead” valve volumes taken into the sampling tank. The other two o-rings of polymer elastic material are placed between the base and valve body on both sides of the wall of the sampling tank. The base and valve body are connected by snap-fit, forming an integral connection, due to the protruding elements on both of these parts, providing a reliable joint. The fields at the base of the valve have a thickness decreasing from the center to the periphery to provide a better fit when using the valve in sampling containers with flexible sheath sheets of this flexible sheath when such a sampling container is emptied, in order to minimize the remainder of the previous gas sample.

The specified set of distinctive features allows to achieve a technical result, which consists in increasing the valve gas tightness for the sampling tank and providing the possibility of “flushing” with the carrier gas or gas taken into the sampling tank the “dead” gas-tight valve volumes, as well as in increasing the service life of the valve and the sampling tank, used with it.

Brief Description of the Drawings

The invention is illustrated in FIG. 1, 2, 3, 4, 5.

In FIG. 1 shows a General view of the valve Assembly in section.

In FIG. 2 shows a detail of the valve in the context.

In FIG. 3 shows a cross-sectional view of the valve in the open position.

In FIG. Figure 4 shows a cross-sectional view of the valve in the “closed” or “flushing” position.

In FIG. 5 illustrates the flushing process of the valve.

The implementation of the invention

The proposed solution of the gas tight valve for a sampling tank contains (Fig. 1) a base 1, a housing 2, at least four o-rings 5, 6, 7 and 8 of polymer elastic material and a spindle 3 with a spool 3a. The spindle also acts as a valve handle 3B for controlling gas flows and the role of a channel 3b for gas flows.

On the spindle (Fig. 2) 3 with the spool 3a, two grooves 3g and 3d are formed for the sealing rings 7 and 8 from a polymer elastic material with low gas permeability. The groove 3g on the spindle 3 and the groove 3D on the spool 3a for the sealing rings 7, 8, as well as part 1a of the base 1 and part 2a of the valve body 2, to which the said sealing rings are adjacent in the open and closed position of the valve, have a shape corresponding to the shape these o-rings. This solution can significantly increase the valve gas tightness. Between the grooves 3g and 3d on the spindle 3 is a cylindrical thread 3zh, through which the base 1 and the spindle 3 are connected and the spool 3a is moved when the valve handle 3c is rotated. Thread 3g is preferably performed in small steps.

The channel for gas flows 3b inside the valve ends with a hole 3e made perpendicular to its axis in that part of the spindle where the thread is located. Through said opening 3e, gas flows pass into (from) the channel. O-rings 7 and 8 located in the grooves are made of polymer elastic material with low gas permeability.

O-rings 5 and 6 are placed between the base 1 and the valve body 2 on both sides of the wall 4 of the sampling tank (Fig. 1), have a rectangular cross section and are made of polymer elastic material. The base 1 and the valve body 2 are connected by snap-fit (Fig. 2) due to the protruding elements 1B and 2B, forming an integral connection, which ensures reliable articulation of the valve elements in terms of both mechanical integrity and gas tightness.

The fields 1b of the base 1 and the fields 2b of the valve body 2 are expediently made of the same diameter and equal to the outer diameter of the sealing rings 7 and 8. Moreover, the fields 1b of the base of the valve 1 have a thickness decreasing from the center to the periphery to provide a better fit when using the valve in flexible sampling containers shell to each other sheets of this flexible shell, when such a sampling tank is empty, in order to minimize the remainder of the previous gas sample. This will allow better “flushing” of the sample container with a flexible shell when reusing the sampler.

The valve operates in two positions "open" (Fig. 3) and "closed" (Fig. 4). In the "closed" position, it is also possible to "flush" the "dead" volumes of the valve and, therefore, external channels for gas flows connected to the valve. In FIG. 5 illustrates the movement of gas flows during a “flush”.

The device operates as follows.

In order to open the valve, it is necessary to turn the valve knob 3c counterclockwise (if the thread 3zh is “right”) until it stops. In this case, in the "open" position (Fig. 3), the sealing ring 8 abuts against the counterpart 2a of the valve body, thereby ensuring the passage of the gas stream into the sampling tank.

In order to close the valve, it is necessary to rotate the valve knob 3c clockwise (if the thread 3zh is “right”) until it stops. At the same time, in the “closed” position (Fig. 4), the sealing ring 7 abuts against the counterpart 1a of the valve base, thereby locking the gas sample in the sampling container. The forces arising from the compressed elastic sealing ring 7 will prevent the rotation of the spindle 3, which will not allow the valve to open spontaneously, for example, during shaking of the sampling container during transportation.

In order to "flush" the "dead" volumes of the valve (Fig. 5) before sampling, it is necessary to pass through the valve in the "closed" position a small portion of carrier gas or gas taken into the sampling tank. In this case, external channels for gas flows connected to the valve can be “washed out” without the use of additional fittings, such as, for example, a three-way valve. "Flushing" the "dead" volumes of the valve will ensure representativeness of the sample both during sampling in the sampling tank and when moving the sample from the sampling tank to the measuring system.

In order to enable sampling from a sampling vessel with a flexible shell equipped with the proposed valve using a syringe, but without piercing the flexible shell or septa (barrier element) intended for this, the valve handle 3c is made in the form of a Luer with dimensions suitable for connection to sampling syringes. Thus, unlike the known solutions described above, this solution allows an unlimited number of times to take a sample both into the sampling syringe and without the use of a syringe.

The constituent parts 1, 2 and 3 of the proposed valve can be made of plastic by molding, which makes it easy to obtain a large circulation of products with low cost. The proposed valve design does not require high accuracy of compliance with the geometric dimensions of its elements, and the specified manufacturing method allows to provide the required quality.

The absence of rubbing valve elements provides a high initial gas tightness over the entire duration of use of the product. The locking elements of the valve experience only compressive forces, and the threaded parts do not participate in the regulation of gas flows.

A valve sample made of ABS plastic (acrylonitrile butadiene styrene) with silicone (dimethylsiloxane) O-rings provided a leak rate, for example, a hydrogen sample (as the most poorly retained gas) when stored under slight overpressure at room temperature, approximately 0.2 cm ³ per day. Such an indicator of preservation is enough to transport the sample from the object where it was taken to the laboratory, ensuring the representativeness of this sample.

List of references

1. Patent US 7219874 "Access fitting for gas sampling bag".

2. CA patent 2668849 "Gas sample bag with fitting and valve".

3. Patent CN 201514346 U “Gas sampling bag”.

Claims (3)

1. A gas tight valve for a sampling vessel, comprising a base, a housing, at least four o-rings made of polymer elastic material and a spindle with a spool, the spindle also serving as a valve handle for controlling gas flows and the role of a channel for gas flows, characterized in that two grooves are formed on the spindle with the spool for two o-rings, said grooves and parts of the base and valve body to which the o-rings of the spindle and spool are adjacent in open and in in the open position of the valve, they have a shape corresponding to the shape of these o-rings, between the grooves on the spindle there is a thread through which the base and spindle are connected and the valve moves when the valve handle is rotated, the channel for gas flows inside the valve ends with an opening made perpendicular to its axis, through which flows into (from) the channel gas flows in the part of the spindle where the thread is located, moreover, in the mentioned grooves there are O-rings made of polymer of other material with low gas permeability, providing the possibility of "flushing" with a carrier gas or gas of "dead" valve volumes taken into the sampling tank, the other two o-rings of polymer elastic material are placed between the base and the valve body on both sides of the wall of the sampling tank. 2. The valve according to claim 1, characterized in that the base and body are connected by snap-fit, forming an integral connection, due to the protruding elements on both of these parts, providing a reliable joint. 3. The valve according to claim 1, characterized in that the existing fields at the base of the valve have a thickness decreasing from the center to the periphery to provide a better fit when using the valve in sampling containers with a flexible sheath of sheets of this flexible membrane when such a sampling container is empty, with the aim of minimizing the remainder of the previous gas sample in it.

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