RU2775190C1 - Shut-off valve - Google Patents

Abstract

FIELD: valve engineering.

SUBSTANCE: invention relates to valve engineering and is intended for use as a shut-off device for blocking the flow of the working medium in the pipelines of power plants. The shut-off valve contains a body with nozzles, a shut-off body fixed to the rod and interacting with the sealing seat, an oil seal assembly, and a lid. Its recess part as part of a lid with an oil seal assembly, a shut-off body, a rod, a sealing seat is made in the form of a shut-off block installed in the housing by a single assembly unit with sealing through sealing elements, while the lid is made in the form of an inverted cup having a bottom and a cylindrical shell with a through hole, and the sealing seat is made on the outer end of the lower end of the cylindrical shell. The lower part of the cylindrical shell is equipped with a centering element made in the form of a guide sleeve with windows for the passage of the working medium, the inner surface of which interacts with the outer surface of the shu-off body.

EFFECT: invention is aimed at creating a Kingston-type valve that provides the possibility of restoring the valve’s operability in case of defects by replacing defective parts when dismantling the recess part in the form of a shut-off block in crowded conditions directly on the object.

4 cl, 2 dwg

Description

The invention relates to valve building and is intended for use as a shut-off device to shut off the flow of the working medium in pipelines, in particular in the pipelines of nuclear power plants, characterized by difficult operating conditions.

Shut-off valve designs are known (see utility model patent RU 109254 U1, class F16K 1/32, F16K 27/02, 2011, patent for invention WO 2004094878 A1, class 7F16K 1/42, 2004), containing a housing in which a replaceable seat is placed with a sealing surface that interacts with a shut-off body mounted on a rod controlled by a drive. A replaceable seat with a sealing surface is pressed against the body by means of a bushing. The use of a replaceable seat makes it possible to improve the conditions for the necessary work to restore the tightness of the sealing surfaces of the valve.

The disadvantage of the known designs of the shut-off valve is a decrease in the tightness of the gate due to the loss of working force from the action of the working pressure of the medium on the stem and bellows, which entails an increase in the weight and size characteristics of the drive and the valve as a whole. Another disadvantage is the decrease in the reliability of ensuring the tightness of the valve relative to the external environment along the stem and the main connector when the emergency pressure of the medium acts on the gate, which is especially unacceptable when valves are used in nuclear power plants.

The closest in technical essence and the achieved result is a Kingston type shut-off valve, when the movement of the stem to close is up, and to open it is down (see “Ship fittings”, Kashansky M.S. and others, publishing house “Shipbuilding”, Leningrad , 1975, p. 270, Fig. 186), consisting of a body with nozzles and a sealing seat, a stem and a shut-off body. A stuffing box assembly is installed in the body, sealing the rod.

When the valve is closed, the pressure of the working medium acts directly on the valve, creating an additional force on the sealing surfaces of the valve - the effect of self-sealing of the valve occurs.

A disadvantage of the well-known design of the shut-off valve is that in the event of a loss of tightness in the seal of the shut-off body and the body seat, the entire valve must be dismantled, and when the valve is connected to the pipeline by welding, it must be cut out of the pipeline with the replacement of part of the pipe.

Performing repair work to restore the performance of such a valve of the kingston type requires a lot of labor and time-consuming, which reduces its maintainability and degrades performance. This is especially important when using the valve in security systems and in conditions of regular crowding at the facility.

The well-known design is applicable to the angular version of the shut-off valve body, since the shut-off body can be inserted into the pipe only coaxially with the stem on which it is fixed. When the shut-off valve is made with both side branch pipes, the design is unacceptable: it is impossible to assemble the valve.

We choose this technical solution as a prototype.

The technical problem solved by the invention is the creation of a valve of the kingston type, which provides the possibility of restoring the working surfaces of the sealing seat and the shut-off body and the operability of the valve in case of defects in other parts by replacing defective parts when dismantling the removable part in the form of a shut-off block in cramped conditions directly at the facility.

The solution of this problem allows to increase the maintainability of the valve, to expand the operational capabilities and range of use.

This problem is solved due to the fact that in a shut-off valve containing a body with branch pipes, a shut-off element fixed on the stem and interacting with the sealing seat, a stuffing box assembly, the valve is equipped with a shut-off block consisting of a cover with a stuffing box assembly, a shut-off body and a stem and installed into the body in the form of a single assembly unit with sealing through the sealing element, while the cover is made in the form of an inverted cup having a bottom and a cylindrical shell with a through hole, and the sealing seat is made at the outer end of the lower end of the cylindrical shell.

The lower part of the cylindrical shell of the inverted cup is provided with a centering element, made, for example, in the form of a guide sleeve with windows for the passage of the working medium, the inner surface of which interacts with the outer surface of the locking element.

Installing the shut-off block in the body makes it possible to replace the defective sealing connection of the shut-off body with the seat without dismantling (cutting out) the valve body from the pipeline directly at the site in cramped conditions. Consequently, the maintainability of the valve is ensured, which contributes to the expansion of operational capabilities and range of use.

The supply of the cylindrical shell with a guide sleeve allows for precise installation of the shut-off body relative to the sealing seat of the cylindrical shell of the cover, which eliminates displacement and distortions along the sealing surfaces.

The proposed technical solution is illustrated by drawings:

- figure 1 shows a longitudinal section of the valve, the "open" position;

- figure 2 shows the section A-A of the valve.

The shut-off valve consists of a body 1 with branch pipes and is equipped with a shut-off block consisting of a cover 2 with a gland assembly 3, a stem 4 and a shut-off body 5.

The cover 2 is made in the form of an inverted cup, consisting of a bottom 6 and a cylindrical shell 7, and is sealed with respect to the external environment by a sealing element 8, for example, a gasket installed between the bottom 6 and the body 1. The stuffing box assembly 3 of the stem seal 4 is located in the bottom 6 covers 2.

The cylindrical shell 7 of the cover 2 enters the internal cavity of the body 1 and has its own internal cavity 9, which, when the valve is opened, communicates with the internal cavity of the lower branch pipe and is connected through the through hole 10 with the internal cavity of the upper branch pipe.

On the outer end surface of the lower end of the cylindrical shell 7 from the side of the lower branch pipe, a sealing seat 11 is made, which interacts with the sealing belt 12 of the shut-off body 5 in the "closed" position of the valve.

The lower part of the cylindrical shell 7 is provided with a centering element, for example, a guide sleeve 13 with windows 14 for the passage of the working medium. The inner surface of the guide sleeve 13 interacts with the outer surface of the locking element 5, ensuring its centering relative to the sealing seat 11.

The rod 4 is centered relative to the inner surface of the cylindrical shell 7 in the form of a guide element 15. The guide element 15 is made in the form of a disk separating the upper inner cavity of the cylindrical shell 7 from the flow of the working medium.

Details of the removable part of the valve in the composition of the shut-off body 5, fixed on the stem 4, cover 2 with stuffing box 3, made in the form of a bottom 6 and a cylindrical shell 7 with a sealing seat 11, assembled into one unit - a shut-off block, installed in the body 1 in the form single assembly unit.

The locking block is sealed with the body 1 by a sealing element 16 installed between the end face of the lower end of the cylindrical shell 7 and the end of the groove in the body 1.

The shut-off valve works as follows.

In the initial position, the valve is shown in the "open" position. The working medium can pass through the internal cavities of the lower branch pipe, the cylindrical shell 7 and the upper branch pipe, or vice versa.

Under the action of the force developed by the drive, the stem 4 with the shutoff body 5 moves up until the stop of the sealing belt 12 of the shutoff body 5 into the sealing seat 11 of the cylindrical shell 7. When the shutoff body 5 moves, the flow area of the cylindrical shell 7 is blocked, cutting off the communication of the medium through the branch pipes of the housing 1 .

In case of loss of tightness in the connection of the sealing seat 11 with the sealing belt 12 of the shut-off body 2, as well as in case of loss of operability of other parts of the valve, the shut-off block consisting of the stem 4 with the shut-off body 5 and the cover 2 with the stuffing box seal 3 and the sealing seat 11 must be dismantled from building 1 for repair in the factory using special tools and tests on the stand.

In case of urgent repair, a new one from the set of repair parts is used instead of a defective locking block.

The use of a shut-off block as a removable part makes it possible to ensure the maintainability of a kingston-type shut-off valve with a body welded to the pipeline and reduce the complexity and duration of its repair and restoration work in the conditions of the facility, thereby expanding its operational capabilities and scope.

Claims (4)

1. Shut-off valve containing a body with branch pipes, a shut-off element interacting with a sealing seat, a stem, a stuffing box assembly, a cover, characterized in that its removable part as part of a cover with a stuffing box assembly, a shut-off body, a stem, a sealing seat is made in the form of a shut-off a block installed in the body as a single assembly unit with sealing through sealing elements, while the cover is made in the form of an inverted cup having a bottom and a cylindrical shell with a through hole, and the sealing seat is made at the outer end of the lower end of the cylindrical shell. 2. Shut-off valve according to claim 1, characterized in that the lower part of the cylindrical shell of the lid is provided with a centering element, the inner surface of which interacts with the outer surface of the locking element. 3. Shut-off valve according to claim. 2, characterized in that the centering element of the cylindrical shell is made in the form of a guide sleeve with through windows. 4. Shut-off valve according to claim 1, characterized in that a guide element is installed on the stem, the outer surface of which interacts with the inner surface of the cylindrical shell.

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