SU1455108A1 - Ball-type cock - Google Patents

Abstract

The invention relates to reinforcement building, in particular to ball valves, and can be used to shut off large diameter pipelines under high pressure. The purpose of the invention 5 12 to improve the reliability of the crane by providing a pre-stress-strain state of the seal that is uniform across the cross section. The implementation of the outer surface 8 of the inner sleeve 5 in the area of the socket of the conical fitting, converging with the conical surface 10 of the outer sleeve 4, and the fulfillment of the profile of the sealing ring 6 with an allowance relative to the conical surface 8 of the inner sleeve 5 provide in the process of pressing the sealing ring 6 into the socket of the sealing wedge effect, in which high compression forces of the sealing ring 6 in the sealing nest are obtained and its intensity (ring) is reduced when the ball plug 2 rotates. 3 or . 4 Oh. (O (L SP C71 // jig.2

Description

The invention relates to a reinforcement structure, in particular to a ball extreme, and can be used to ensure the tightness of valves of ball valves designed to shut off large diameter pipelines under high pressure.

The aim of the invention is to increase the reliability of the operation of the crane by ensuring that the preliminary stress-strain state of the sealing element is uniform over the cross section.

Fig; 1 shows a ball valve with a fixed ball valve and a floating seal assembly, a slit; in fig. 2 — sealing assembly; I on fig. 3 - seal when it is squeezed: tin (on the lower part of fig. 3, I shows the position in the process of reduction, and on the upper part - the moment of the end i of the saddle assembly and the complete compression of the seal in the slot) ; . The ball valve contains: 1 ball plug 2 in the housing; a spindle 3 compacted with knots: lottery, consisting of detachable metal ring seats, each of which includes an outer 4 and an inner 5 sleeve, contact- ing; between the surface of the cylindrical I and forming the nest I of the elastic sealing ring Ia 6 with the annular slot 7 for the exit ring 6. The nest of the seal is formed by the I inner annular bore in the outer sleeve 4 and the outer surface 8 of the inner sleeve 5. The cylindrical surface 9 of the bore is bounded on the cork side by a conical surface 10, and on the opposite side by a thrust surface 11 located perpendicular to the longitudinal axis of the crane. The outer surface 8 of the inner sleeve 5 in the area of the socket embedment is made conical with an angle of 1 half-cone no more than 30. The conical surfaces 10 and 8, respectively, of the bore and the inner sleeve 5, forming an annular slot 7 for exiting the sealing ring 6, are made convergent. The sealing ring 6 is made with a similar profile fitting slot, of the cross section, the conical surface of the sealing ring 6, which is in contact with the conical

five

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five

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five

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45

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surface 8 of the inner sleeve 5, is made with an allowance for the state of reduction (i.e., the pre-stressed-deformed state in the socket corresponding to the complete seal assembly performed by tightening the sleeves 4 and 5 with bolts or studs 12.

Line transition to the outer conical surface 8 of the inner sleeve 5 is located in the plane of the thrust surface 11 of the outer sleeve 4.

The preliminary pressing of the sealing rings 6 to the surface of the plug 2 is carried out by means of springs 13, acting in the axial direction on the floating separable seats.

The ball valve works as follows.

Under the action of the drive through the spindle 3, the torque is transmitted to the plug 2. Turning 90 degrees, the plug 2 opens or blocks the flow of the working medium in the pipeline. The position of the plug 2, in which its flow area coincides with the flow area of the pipeline, corresponds to the open position of the crane. In case of a deadlock plug 2, the sealing rings 6 prevent the flow of the working medium from the pipeline section under pressure to the section protected from the flow of the working medium. At the same time, the tightness of the sealing plug is ensured by pressing the part of the rings 6 protruding from the slot 7 to the surface of the plug 2 by acting on floating seats consisting of sleeves 4 and 5, the axial force from the springs 13 and the pressure drop on each saddle of the seal. The tightness of the seal is achieved by exceeding the values of the maximum contact stresses (specific pressures) at the junction of the sealing ring 6 with the surface of the plug 2 above the value of the lockable pressure.

In a ball valve, a high compression force is achieved by using a wedge effect when pressing the sealing ring 6 into the sealing slot mechanically by tightening the inner 5 and outer 4 bushings with studs or bolts 12 during assembly of the seal assembly. At the same time press-in (crimp)

314

the sealant many times exceeds the limiting forces of tightening the studs (bolts) 12, which follows from the analysis of the forces acting on the sealing ring (FIG. 3),

When the sleeves are evenly tightened, the force of tightening the sleeves from the total tightening force of the bolts acts in the axial direction on both the outer 4 and the inner 5 sleeves, and the force vectors are directed towards each other (shrinking the sleeves). The conical surface of the inner sleeve is in contact with the conical surface of the sealing ring, which has an allowance h. On this conical contact surface, two forces are generated that act on the sealing ring (reactions of the conical surface of the sleeve) —the force of normal pressure and the force of friction.

These forces form the resultant force acting on the sealing ring 6.

The normal pressure force is the active force that forces the sealing ring 6 into the seal socket.

The strength of friction in this case is harmful force.

When the sealing ring is pressed into the seat, a wedge effect takes place, consisting in exceeding the force of the normal pressure (pressing force) over the force of shrinking of the sleeves and in the sliding of the contacting conical surfaces of the sealing ring and the inner sleeve relative to each other, which eliminates the turning of the sealing ring out of the seat when pressed in.

 The angle cf, which determines the possibility of obtaining the specified wedge effect, is selected depending on the ratio of forces acting on the sealing ring in the projections on the longitudinal axis of the kggan, and on the friction coefficient (fтр) of the contacting surfaces of the sealing ring and the inner sleeve, while inequality

Claims (1)

f tr (0.5 - sin o (,) / coso. The invention A ball valve containing a ball stopper placed in a housing and a seal assembly in the form of a detachable annular seat consisting of outer and inner bushings that are in contact with each other along a cylindrical surface and form an insert sealing ring of an elastic sealing ring, having an annular slot for the exit ring, with the seal nest formed by the outer surface of the inner sleeve and the inner annular bore in the outer sleeve, cylinder 1 the surface of which is limited from the side of the conical tube surface, and on the opposite side, a stop surface perpendicular to the longitudinal axis of the crane, the sealing ring being made with a similar cross-section profile embedment slot, characterized in that, in order to increase the reliability of operation, the outer surface of the inner sleeve in the embedment socket zone is made conical, converging with the conical surface of the outer sleeve, and the transition line to the conical surface of the inner sleeve is located in the plane of the thrust surface of the outer sleeve, and The configuration of the cross-sectional profile of the sealing ring is made with an allowance along its conical surface relative to the conical surface of the inner sleeve. ftie.3 //