RU2615892C1 - Safety valve of improved stability - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: safety valve of improved stability comprises a housing with the angular arrangement of the inlet and outlet fittings and seat, piston, spring loaded valve, the working spring and the adjusting screw. The spring-loaded valve and the piston are interconnected via a pin and interact with the same guide formed in the valve body. Between the piston, wherein the annular groove are formed by the sealing rings, and the spring-loaded valve is mounted damping element formed as a sleeve in contact with the valve spring at the outer diameter. The piston is placed in a hollow casing mounted on a support, which supports the operating spring. Between the side walls of the hollow support and guide body, the sleeve is arranged of antifriction material. In the place of the threaded connection with the housing cup, annular ledge is clapped with the possibility of interaction with the lower part of the hollow support.

EFFECT: increase of reliability and stability of the safety valve.

2 dwg

Description

The invention relates to pneumatic devices and is intended to protect against excess pressure of gases above the permissible level in pipelines or tanks and can be used in various industries for working with compressed gases, for example, for space technology in ground-based testing equipment.

Known safety device (AC No. 477276), comprising a housing with a saddle, a locking plate, a damping device, a spring.

The disadvantages of the known safety device are the low reliability of the accuracy of maintaining the flow characteristics due to the inconsistent magnitude of the friction force due to possible misalignment of the rod in the guide surfaces, consisting of two belts of a set of fluoropolymer crackers, the absence of a fixed direction of the working spring leads to the swing of the lower support coil, and therefore to uneven pressure of the valve to the seat, which reduces the tightness of the valve in the closed position, and the absence of direct pressure damping of the valve locking plate during operation in the flow mode (the valve plate is raised above the seat by the amount of the stroke) can lead to non-damping plate vibrations (self-oscillations) within the stroke between the seat and the articulated rod stop, which has increased inertness due to forces friction in breadcrumbs.

Known safety hydraulic valve (patent RU No. 2379567), consisting of a housing, a locking element, a spring, a damping sleeve, a control element.

The disadvantages of the known safety hydraulic valve are the low reliability and the possibility of unstable operation (self-oscillations) of two valves at once, the main and auxiliary, as a result of the lack of direction during operation of the auxiliary valve after it is torn from the seat and the "swing" of the support coil of the spring, as well as an unstable value of the friction force due to the gap between the shank of the locking element and the damping sleeve, which causes pressure pulsation in the internal cavity of the main valve and, as a result, in binds its oscillations.

The closest in design features to the claimed valve is a safety valve of the mixed type ("Power pneumohydraulic systems" edited by Corresponding Member of the USSR Academy of Sciences V.P. Barmin. M: Moscow, 1965, p. 68, Fig. 43) - a prototype that includes a housing with a saddle and an angular arrangement of the inlet and outlet nozzles, a valve, a valve spring, a piston, a working spring, an adjusting screw.

The disadvantages of the safety valve mixed type are:

- low reliability of the tightness of the valve seat on the seat due to the possible incomplete fit of the valve to the seat due to misalignment of the valve and the piston, the direction of which is carried out in various parts (the valve slides along the piston and the piston along the body), and also due to the possibility of contact print bias from the seat on the valve seal in subsequent closures;

- low reliability of the accuracy of maintaining the flow characteristics due to the high friction force between the housing and the piston, which simultaneously acts as a sensing element for the output pressure and support of the working spring, which leads to a large difference between the opening and closing pressure of the valve (for rubber o-rings , usually, greater friction hysteresis), while the valve itself is not damped;

- loss of operability of the valve due to exit from contact with the housing of the piston sealing element (with a large amount of lift);

- unstable operation (self-oscillations) due to insufficient friction between the valve, piston and auxiliary spring.

The objective of the technical solution is to eliminate the existing disadvantages, namely improving the reliability and stability of the safety valve increased stability.

The problem is solved in that in a safety valve of increased stability, comprising a housing with an angular arrangement of the inlet and outlet fittings and a seat, a piston, a spring-loaded valve, a working spring and an adjustment screw, according to the invention, the spring-loaded valve and the piston are connected by a pin and interact with the same guide made in the valve body, and between the piston in which the annular grooves for the sealing rings are made, and the spring-loaded valve installed n a damping element made in the form of a sleeve in contact with the valve spring along the outer diameter, and the piston is placed in a hollow support installed in the housing, on which the working spring rests, while a sleeve of antifriction material is placed between the side walls of the hollow support and the guide of the housing, and in place of the threaded connection of the housing with the glass, an annular stop is clamped with the possibility of its interaction with the lower part of the hollow support.

The drawings show the design of the claimed device:

in FIG. 1 shows a General view of the device in section;

in FIG. 2 is a view A from FIG. one.

The safety valve of increased stability (Fig. 1) consists of a housing 1 with a seat 2 and an inlet fitting 3 and an outlet fitting 4 screwed into it at an angle, a spring-loaded valve 5 and a piston 6, interconnected by a pin 7 (Fig. 2) and interacting with the same guide 8 made in the valve body 1. Between the piston 6 with the annular grooves 9, in which the sealing rings 10, for example rubber, are located, and a spring-loaded valve 5, a damping element 11 is made, made in the form of a sleeve, simultaneously contacting with the spring 12 along the outer diameter. The piston 6 is placed in the hollow support 13 installed in the housing 1, on which the working spring 14 is supported. Between the side walls of the hollow support 13 and the guide 8 of the housing 1 there is a sleeve 15 made of antifriction material, for example fluoroplastic. In place of the threaded connection of the housing 1 with the glass 16, an annular stop 17 is clamped with the possibility of its interaction with the lower part of the hollow support 13, for example, through the heel 18. The adjusting screw 20 is screwed into the sleeve 19, which is fixedly mounted in the glass 16, through the ball 21 and the plate 22, compressing the working spring 14, while the damping element 11 is installed with a minimum clearance (not shown) between the spring 12, the spring-loaded valve 5 and the piston 6.

Work description

The safety valve of increased stability is set to a predetermined pressure when the working fluid (RT) is supplied to the inlet with a pressure equal to the setting pressure. The adjusting screw 20, when clockwise rotated through the ball 21 and the plate 22, compresses the working spring 14, the force from which is transmitted through the hollow support 13 to the piston 6, where the force from the working spring 14 and the force from the input pressure acting on the piston 6 are compared. The adjustment screw 20 is rotated until the spring-loaded valve 5 comes off the seat 2.

Maintaining the pressure at the inlet to the safety valve with increased stability at a given level is as follows.

The working fluid when fed to the inlet through the inlet 3 enters the working cavity 23 and acts on the unloaded area of the piston 6.

With an increase in the inlet pressure above the adjusting piston 6, it moves, overcoming the force of the working spring 14, and pulls the spring-loaded valve 5 connected to it by the pin 7, which is detached from the seat 2 of the housing 1 and the PT is discharged into the resulting throttle slot through the outlet fitting 4. Pressure at the inlet to the safety valve decreases.

When the pressure at the inlet to the safety valve of increased stability decreases to the value set by the setting, the spring-loaded valve 5, under the action of the working spring 14, lowers onto the seat 2 of the housing 1, the throttling gap closes, and the RT discharge stops.

Improving the reliability and stability of the safety valve increased stability in accuracy of maintaining the flow characteristics is achieved through the use of a damping element 15 made of antifriction material, for example fluoroplastic, providing a stable low coefficient of friction when moving the hollow support 13 relative to the guide 8 of the housing 1; the tightness of the valve seat on the seat - due to the exclusion of the "swing" of the support coil of the working spring 14 after the spring-loaded valve 5 is torn off the seat 2, plane-parallel movement of the moving parts, followed by uniformly pressing the spring-loaded valve 5 to the seat 2; to ensure operability - as a result of constant contact of the sealing rings 10 with the guide 8 of the housing 1 due to the use of the ring stop 17: the size " a " (from the sealing ring 10 to the edge of the guide 8 of the housing 1) is obviously larger than the size "b" (between the ring stop 17 and the lower part of the hollow support 13 or fifth 18, as indicated in Fig. 1).

Stable operation of the safety valve of increased stability is ensured by preventing oscillations of the spring-loaded valve 5 by increasing friction between the spring 12, the spring-loaded valve 5 and the piston 6 by means of a damping element 11 made in the form of a sleeve.

Thus, the proposed technical solution improves the reliability and stability of the safety valve.

Claims (1)

Safety valve with increased stability, comprising a housing with an angular arrangement of the inlet and outlet fittings and a seat, a piston, a spring-loaded valve, a working spring and an adjustment screw, characterized in that the spring-loaded valve and the piston are connected by a pin and interact with the same guide, made in the valve body, and between the piston in which the annular grooves for the sealing rings are made, and a spring-loaded valve, a damping element is installed, made in e bushings in contact with the valve spring on the outer diameter, and the piston is placed in a hollow support installed in the housing, on which the working spring rests, while a sleeve of antifriction material is placed between the side walls of the hollow support and the housing guide, and in the place of the threaded connection of the housing with an annular stop is clamped with a glass with the possibility of its interaction with the lower part of the hollow support.

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