RU2679335C1 - Safety valve of direct action - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to pipeline valves, characterized by high parameters of the working environment. Direct-acting safety valve consists of a body, an inlet nozzle and an outlet nozzle in which a channel is made, and a saddle, a shutter, a bellows connected to the shutter and the glass are installed in the body. Effective area of the bellows exceeds the area of the gate, which allows for reliable opening. Glass is attached to the valve body with a yoke. Stand is mounted on the yoke. Inside the stand, a bellows chamber is formed by means of two bellows coupled to the gate, the bellows having a different effective area. Bellows chamber is connected by a pipeline with the outlet pipe. Cover is fixed on the rack, inside of which is placed a package of cup springs and an adjusting screw.

EFFECT: use of the claimed direct-action safety valve provides passive (without energy supply from the outside) actuation (opening-closing), increases the reliability of actuation with given parameters, provides high accuracy of actuation.

1 cl, 1 dwg

Description

The invention of a direct-acting safety valve relates to pipe fittings characterized by high parameters of the working medium - temperature up to 600 ° C, pressure up to 40 MPa, designed to automatically protect equipment and pipelines from unacceptable excess pressure by dumping excess working medium.

One of the requirements for safety valves is high reliability of operation at specified parameters, accuracy of operation, passive opening and closing of the safety valve without supplying energy from outside.

A direct-acting pressure relief valve is known (Application for invention: 93020161, published July 27, 1996), comprising a locking member with a peripheral circular expansion, pressed against the seat by a return spring, which against the opposite end abuts against a support plate interacting with the adjustment screw. The circular expansion of the locking member is made with a skirt for sliding in the guide cup, the latter having an annular bore with a thrust surface to limit the stroke of the skirt and thereby the locking member. The guide cup is installed in the valve body by means of a threaded connection, providing such a regulation of the stroke of the locking element so that when the valve is opened, pressure overload is minimal, and fluctuations and vibrations of the locking element are eliminated.

The disadvantage of this design is the presence in the flow of elements tightened shut-off body, which reduce the reliability of the design.

Known pulse safety valve (patent application: 2015108474/06, published July 20, 2016), the casing of which is made in the form of two floors of the casings and an intermediate casing installed between them in the form of a partition. A pulse valve is installed in the intermediate housing. The valve shutter is made in the form of a ball, drawn to the saddle by springs using a rod. The cavity between the seat and the rod is communicated through nozzle openings made in the intermediate casing with a drainage cavity. The shutter of the main valve is made in the form of a stepped plunger. At the end of the smaller stage of the last installed sealing element in contact with the seat. The input cavity of the housing communicates with the annular cavity formed by the surfaces of the stepped plunger and the surfaces of the housing for this plunger, through the radial and axial holes and the radial nozzle hole and with the cavity of the main shutter spring through the specified radial and axial holes and the nozzle installed in the stepped plunger.

A disadvantage of the known pulse safety valve is the design complexity, which reduces its reliability.

Known bellows-pulse safety valve (patent application 2014126036, published January 27, 2016), comprising a housing with a seat, a valve with a stem and an actuator controlled by a relief pulse valve, characterized in that the actuator of the safety valve is a bellows, one end of which is fixedly connected to housing cover, the other end is connected to the valve stem with the possibility of axial movement under the influence of the difference of forces from the internal pressure in the bellows and from the stiffness of the bellows arising during opening and closing and a control relief pulse valve.

The disadvantage of this design is the insignificant force pressing the shutter against the seat, leaks correspondingly occur, leading to unauthorized operation of the safety valve or to failure of operation.

The closest in purpose, technical nature and the achieved result to the claimed direct-acting safety valve is a safety bellows valve (application for a utility model: 2003121119/20, published 10.10.2003), comprising a housing with inlet and outlet channels, a locking member loaded towards the seat side with a seat seal and a bellows associated with a locking body and with a housing in which the outer diameter of the bellows is made equal to the outer diameter of the seal of the saddle, and the inner diameter of the bellows, respectively the inner diameter of the seat seal.

The disadvantage of this design is the insignificant force of pressing the shutter against the seat; accordingly, leaks occur, leading to unauthorized operation of the safety valve or to failure of operation.

The aim of the invention is to provide high tightness of the shutter, ensuring high reliability of operation at specified parameters, improving the accuracy of operation, passive opening and closing of the safety valve without supplying energy from outside.

The task is achieved in that the direct-acting relief valve consists of a housing, an inlet pipe and an outlet pipe in which the channel is made and chokes are installed, a saddle, a shutter, a bellows connected to the shutter and a cup are installed in the housing, characterized in that the effective area of the bellows exceeds the shutter area, providing reliable opening, while the cup is fixed to the valve body with a yoke with a stand installed on it, inside of which a bellows chamber is formed by means of two bellows with ase effective area connected to the gate, characterized in that the outlet channel is line-connected with the bellows chamber. A cover is fixed on the rack, inside of which there is a packet of Belleville springs and an adjusting screw.

High shutter tightness is ensured by increasing the specific pressure of the shutter against the seat. In the proposed design, the effective area of the bellows exceeds the area of the shutter. If there is a working pressure inside the valve, in order to ensure the shutter tightness, the force of setting the disk cup package must compensate for the difference in the forces created on the area of the valve and bellows, and the force of adjusting the disk spring package is proportional to the difference in the area of the bellows and the valve, and, accordingly, increases the specific pressure of the valve to the saddle.

High reliability of operation at specified parameters is provided due to the significantly larger effective area of the bellows compared to the area of the shutter, respectively, with increasing pressure of the working medium inside the valve, the force acting on the bellows increases in proportion to the difference between the areas of the bellows and the shutter, which ensures reliable opening of the valve.

Improving the accuracy of operation is ensured by the presence of a package of Belleville springs. The package of Belleville springs during the sequential assembly of the springs provides a gentle linear characteristic in the proposed design, respectively, provides finer tuning and accuracy of operation.

Passive opening of a direct-acting safety valve for given parameters is ensured by the presence of a bellows connected to the valve (bellows actuator), and closing without external energy is provided by the presence of two bellows with different effective areas connected to the valve (bellows actuator) in the bellows chamber.

An example of the proposed safety valve direct acting is presented in the drawings.

In FIG. 1 shows the proposed direct-acting relief valve.

The direct-acting safety valve consists of a housing 1, an inlet pipe 2, an outlet pipe 3 in which chokes 4 are installed. A housing 5 has a seat 5, a valve 6, a bellows 7 connected to the valve 6 and the glass 8. The glass 8 is mounted on the housing 1 with a yoke 9 by means of studs 10 and nuts 11. On the yoke 9, a stand 12 is mounted, inside which a bellows chamber 13 is formed by means of bellows 14 and 15 with different effective areas, the bellows chamber 13 is connected by a pipe 16 to the channel 17 of the outlet pipe 3. A cover 18 is fixed to the stand 12, inside When housing the package of disk springs 19 and the adjustment screw 20.

During normal operation, the direct-acting safety valve is tightly closed, since the force of the disk spring package 19 and the force from the pressure of the working medium on the shutter 6 exceed the force on the bellows 7.

When the pressure rises to the set value of the safety valve (pressure to open the valve), the force on the bellows 7 increases. The force on the bellows 7 exceeds the total force on the shutter 6 and the setting force of the disk spring package 19. The shutter 6 opens, the working medium enters the outlet 3, in which chokes 4 are installed, at the same time the medium enters the bellows chamber 13, organized by two bellows 14 and 15 with different effective area.

The pressure of the medium in the safety valve drops. The total force created by the disk spring package 19 and the force created by the pressure in the bellows chamber 13 acts on the valve 6. When the pressure drops to the closing pressure, the total force created by the disk spring package 19 and the force created by the bellows 14 exceeds the force of the bellows 7 and 15 on opening, the valve closes.

The areas of the bellows always remain constant, the operation of the valve (opening and closing) at the set pressure depends only on the spring setting for the valve operating pressure.

The use of the claimed direct-acting safety valve increases the reliability of operation at specified parameters, provides higher accuracy of operation, and provides passive (without supplying energy from outside) actuation (opening-closing).

The claimed valve meets the current requirements of safety and competitiveness in technical, economic and operational indicators.

Information sources:

1. Description of the application for invention: 93020161. Published: 07/27/1996

2. Description of the application for invention: 2015108474/06. Published: July 20, 2016.

3. Description of the application for invention: 2014126036. Published: 01/27/2016.

4. Description of the application for a utility model: 2003121119/20. Published: October 10, 2003. (Prototype).

Claims (1)

Direct-acting relief valve, consisting of a housing with a seat installed in it, an inlet pipe and an outlet pipe having a channel with installed chokes, a valve connected to a bellows, characterized in that the effective area of the bellows exceeds the area of the valve, and the channel of the outlet pipe is connected to the bellows a camera organized by two bellows connected to the shutter, while the bellows have a different effective area.

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