CN214889112U - Pressure measuring joint sealing mechanism - Google Patents

Abstract

The invention discloses a pressure measuring joint sealing mechanism which comprises a valve seat, a valve core and a spring, wherein the valve core is formed by assembling a core body, a push rod shaft and a soft sealing gasket, the soft sealing gasket is positioned in a semi-closed annular cavity formed by the core body and the push rod shaft, and the end surface of an annular sealing boss of the valve seat is contacted with the soft sealing gasket to form sealing. The invention has simple mechanism design and easy processing, and simultaneously, because the annular sealing boss on the valve seat is vertical to the surface of the soft sealing gasket, the destructive shearing force to the surface of the soft sealing gasket in the use process of the valve is avoided, thereby effectively protecting the surface of the soft sealing gasket and solving the defects in the prior art.

Description

Pressure measuring joint sealing mechanism

Technical Field

The invention relates to the technical field of pressure measuring joint sealing, in particular to a pressure measuring joint sealing mechanism.

Background

The pressure measuring joint in the ISO15171-2 standard form is widely applied to the hydraulic and gas industries, and the sealing mechanism of the pressure measuring joint mainly comprises three main forms, namely ball sealing, piston soft sealing and conical surface soft sealing in the current market.

The ball seal is formed by hard contact between the steel ball and the sealing surface on the valve seat, can bear higher pressure, but has high requirement on the machining precision of the valve seat, and is difficult to meet the requirement of common equipment.

The piston soft seal and the conical surface soft seal are two common soft seal forms of the pressure measuring joint, a soft seal groove is added in the middle of the metal valve core, and the soft seal forms seal between the valve core and the valve seat, so that the two seal structures are easier to process compared with a ball seal structure. The two soft sealing mechanisms have a common characteristic that in a free state, the outermost side face of the soft seal must protrude out of the outer surface of the metal valve core, and the width of the soft seal groove must be larger than the thickness of the soft seal so as to ensure that the soft seal material can deform and form a seal under pressure. The structure is characterized in that when the pressure measuring joint is about to be opened and a small gap is formed between the valve core and the valve seat, the side face of the soft seal is pushed to a sharp angle of the side of the soft seal groove due to internal pressure, and a shearing force is formed in the soft seal.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a pressure measuring joint sealing mechanism which adopts a soft sealing mode in a semi-closed annular cavity, has higher sealing specific pressure and is easy to process, and simultaneously eliminates the internal shearing force which causes the damage of the soft sealing surface as described in the background technology, thereby solving the defects of the prior art.

The technical scheme is as follows:

in order to solve the above problems, the present invention provides the following technical solutions: a pressure measuring joint soft sealing mechanism is characterized by comprising:

the valve seat is provided with a flow channel hole, an annular sealing boss and a limiting plane, the flow channel hole is positioned in the center of the annular sealing boss, and the limiting plane is positioned at the root part of the annular sealing boss;

the valve core consists of a core body, a push rod shaft and a soft sealing gasket; the core body sealing end is a semi-closed cavity with an opening flange, and the center of the bottom of the cavity is provided with a threaded hole connected with the push rod shaft; one end of the push rod shaft is provided with an external thread which is connected with an internal thread at the center of the bottom of the semi-closed cavity of the core body, the other end of the push rod shaft is provided with a guide rod part, the outer diameter of the guide rod part is in clearance fit with a flow passage hole of the valve seat, and the middle part of the guide rod part is in interference fit with a hole of the soft sealing gasket; the core body and the push rod shaft are assembled to form a semi-closed annular cavity; the soft sealing gasket is positioned at the bottom of a semi-closed annular cavity formed by the core body and the push rod shaft, an inner hole of the soft sealing gasket is tightly attached to the outer diameter of the push rod shaft, the bottom of the soft sealing gasket is tightly attached to the bottom of the semi-closed annular cavity, the side of the soft sealing gasket is tightly attached to the side of the semi-closed annular cavity, and a gap is formed between the top plane of the soft sealing gasket and the top of the semi-closed annular cavity; the outer diameter of the non-threaded end of the push rod shaft and the mouth flange of the sealing end of the core body form an annular orifice which is in clearance fit with an annular sealing boss on the valve seat; after the valve core is installed, under the condition of no fluid pressure, the distance from the top surface of the soft sealing gasket to the end surface of the core body is smaller than the distance from the end surface of the annular sealing boss on the valve seat to the limiting plane;

and the compression spring is used for pushing the valve core when no pressure exists in the system, and the top surface of the soft sealing gasket is attached to the end surface of the annular sealing boss of the valve seat to form sealing.

Preferably, the core may be integrally formed with the push rod shaft.

Preferably, the guide rod part of the push rod shaft is provided with a blind hole on the end surface, and a radial through hole is arranged on the excircle, and the radial through hole is connected with the blind hole so as to allow the fluid in the pressure measuring joint to quickly flow out and reduce the impact on the surface of the soft sealing gasket when the fluid in the joint rushes out.

(III) advantageous effects

The pressure measuring joint sealing mechanism is simple in structure and easy to process, the push rod shaft of the pressure measuring joint is pushed open by the ejector rod of the pressure measuring gauge line, the surface of the soft sealing gasket is always attached to and wrapped on the end face of the annular sealing boss under the action of internal pressure before the pressure measuring joint is opened, and once the end face of the annular sealing boss is separated from the surface of the soft sealing gasket, namely the pressure measuring joint is opened, the internal pressure of the system can push the soft sealing gasket to the bottom of the semi-closed annular cavity. In the opening and closing processes of the pressure measuring joint, the soft sealing gasket cannot be subjected to destructive shearing force caused by the soft sealing in the background technology, so that the sealing effect is ensured, and the damage of the soft sealing is also prevented; meanwhile, through the design of the valve seat limiting plane and the gap between the top surface of the soft sealing gasket and the top of the semi-closed annular cavity, when the end surface of the core body is in contact with the valve seat limiting plane, the soft sealing gasket is still positioned in the valve core semi-closed annular cavity and cannot be squeezed into the gap between the valve seat annular sealing boss and the valve core, so that excessive deformation of the soft sealing gasket under the high-pressure condition is prevented, and the whole sealing mechanism can be applied to high pressure and low pressure.

Drawings

FIG. 1 is a schematic view of the seal of the present invention in a sealed condition;

FIG. 2 is a schematic view of the valve seat structure of the mechanism of the present invention;

FIG. 3 is a schematic diagram of the core construction of the mechanism of the present invention;

FIG. 4 is a schematic view of the push rod shaft configuration of the mechanism of the present invention;

FIG. 5 is a schematic view of the assembled cartridge of the mechanism of the present invention;

FIG. 6 is a schematic view of the sealing mechanism of the present invention with the pressure tap in a fully open state;

the reference numerals are explained below:

1 valve seat, 2 core bodies, 3 push rod shafts, 4 soft sealing gaskets and 5 compression springs

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the present invention will be further described with reference to the following embodiments.

Referring to fig. 2, a structural schematic diagram of the valve seat 1 is shown, wherein 11 is a sealing end face of an annular sealing boss on the valve seat, 12 is a flow passage hole of the valve seat, 13 is an outer diameter of the annular boss, and 14 is a limiting plane on the valve seat;

FIG. 3 is a partial schematic view showing the sealing structure of the core 2, wherein 21 is a mouth flange, 22 is a cavity side surface of the semi-closed cavity, 23 is an internal thread capable of being connected with an external thread of the push rod shaft 4, 24 is a front end surface of the core, and 25 is a bottom surface of the semi-closed cavity;

FIG. 4 is a schematic structural view of a push rod shaft, in which 31 is a guide rod portion, 32 is a step of a soft packing, 33 is an external thread connected to a core body, and a blind hole 34 is formed in the center of the guide rod portion 31 to be connected to a side through hole 35;

fig. 5 is a schematic diagram of an assembled valve core, which is assembled by first installing the soft sealing gasket 4 into the semi-closed inner cavity 22 at the sealing end of the core body 2, and then screwing the external thread 33 of the push rod shaft 3 with the internal thread 23 of the core body 2 through the central hole of the soft sealing gasket 4; the soft sealing gasket 4 is positioned at the bottom of a semi-closed annular cavity formed by the core body 2 and the push rod shaft 3, the inner hole of the soft sealing gasket is tightly attached to the outer diameter of the push rod shaft 3 at the position 32, the bottom of the soft sealing gasket is tightly attached to the bottom 25 of the semi-closed annular cavity, the side surface of the soft sealing gasket is tightly attached to the side surface 22 of the semi-closed annular cavity, and a gap is formed between the top plane of the soft sealing gasket and the top of the semi-closed annular cavity;

fig. 1 is a schematic diagram of the sealing structure of the present invention in a sealing state, showing the mutual positions of the parts of the structure of the present invention when there is no internal pressure, including a valve seat portion 1, a core body 2, a soft sealing gasket 4 and a push rod shaft 3 together forming a complete valve core, and a semi-closed cavity seal is formed between the valve seat and the valve core under the action of a compression spring 5;

FIG. 6 shows a schematic view of the sealing mechanism of the present invention with the pressure tap in an open state;

the specific working principle is as follows:

the invention relates to a pressure measuring joint sealing mechanism, which comprises a valve seat part 1, wherein a core body 2, a soft sealing gasket 4 and a push rod shaft 3 are assembled together to form a complete valve core, and when no pressure exists in the system, a sealing end surface 11 of an annular sealing boss on the valve seat 1 and an end surface of the soft sealing gasket 4 in the valve core form sealing under the action of a spring 5; when pressure exists in the system, the valve core is pushed to the valve seat by the pressure, the soft sealing gasket 4 deforms under the action of the pressure and is attached to the end face 11 of the annular sealing boss on the valve seat 1, so that the sealing state is kept; when the pressure in the system is increased to a certain value, the front end surface 24 of the core body 2 is contacted with the limiting step 14 on the valve seat 1, and at the moment, even if the pressure in the system is further increased, the valve core is kept in a stop state, so that the soft sealing gasket 4 is prevented from being excessively deformed under high pressure and is always positioned in the annular semi-closed cavity of the valve core and cannot be extruded out of a gap between the annular sealing boss of the valve seat 1 and the valve core;

when a pressure measuring joint applying the mechanism of the invention is connected with a pressure gauge line, a pressure measuring needle is pushed against the top end of a guide rod part 31 of a push rod shaft 3, the whole valve core is pushed to the right side, a compression spring 5 is compressed, when an end surface 11 of an annular sealing boss on a valve seat 1 is separated from the surface of a soft sealing gasket 4, the pressure measuring joint is opened, right side fluid flows out through a gap between the guide rod part 31 of the push rod shaft 3 and a flow channel hole 12 on the valve seat 1, and the valve core is continuously pushed to the right side by the pressure measuring needle to a final pressure measuring position as shown in figure 6, the right side fluid flows out towards the pressure measuring needle through a radial through hole 35 and a blind hole 34 on the push rod shaft;

before the pressure measuring joint is opened, the surface of the soft sealing gasket 4 is always attached to and wrapped on the end surface 11 of the annular sealing boss of the valve seat 1 under the action of internal pressure, and when the end surface 11 of the annular sealing boss and the surface of the soft sealing gasket 4 are in contact once, namely the pressure measuring joint is opened, the internal pressure of the system can push the soft sealing gasket 4 to the bottom 25 of the semi-closed annular cavity. In the opening and closing process of the pressure measuring joint, the soft sealing gasket 4 is not subjected to destructive shearing force caused by the soft sealing in the soft sealing mechanism mentioned in the background art, so that the damage of the soft sealing is prevented, and the effectiveness of the sealing is ensured.

The above is only a preferred embodiment of the present invention, and it should be noted that the above preferred embodiments should not be considered as limiting the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. It will be apparent to those skilled in the art that various improvements and modifications can be made without departing from the spirit and scope of the invention, and these improvements and modifications should also be construed as within the scope of the invention.

Claims (2)

1. A pressure measuring joint soft sealing mechanism is characterized by comprising:

the valve seat is provided with a flow channel hole, an annular sealing boss and a limiting plane, the flow channel hole is positioned in the center of the annular sealing boss, and the limiting plane is positioned at the root part of the annular sealing boss;

the valve core consists of a core body, a push rod shaft and a soft sealing gasket; the core body sealing end is a semi-closed cavity with an opening flange, and the center of the bottom of the cavity is provided with a threaded hole connected with the push rod shaft; one end of the push rod shaft is provided with an external thread which is connected with an internal thread at the center of the bottom of the semi-closed cavity of the core body, the other end of the push rod shaft is provided with a guide rod part, the outer diameter of the guide rod part is in clearance fit with a flow passage hole of the valve seat, and the middle part of the guide rod part is in interference fit with a hole of the soft sealing gasket; the core body and the push rod shaft are assembled to form a semi-closed annular cavity; the soft sealing gasket is positioned at the bottom of a semi-closed annular cavity formed by the core body and the push rod shaft, an inner hole of the soft sealing gasket is tightly attached to the outer diameter of the push rod shaft, the bottom of the soft sealing gasket is tightly attached to the bottom of the semi-closed annular cavity, the side of the soft sealing gasket is tightly attached to the side of the semi-closed annular cavity, and a gap is formed between the top plane of the soft sealing gasket and the top of the semi-closed annular cavity; the outer diameter of the non-threaded end of the push rod shaft and the mouth flange of the sealing end of the core body form an annular orifice which is in clearance fit with an annular sealing boss on the valve seat; after the valve core is installed, under the condition of no fluid pressure, the distance from the top surface of the soft sealing gasket to the end surface of the core body is smaller than the distance from the end surface of the annular sealing boss on the valve seat to the limiting plane;

and the compression spring is used for pushing the valve core when no pressure exists in the system, and the top surface of the soft sealing gasket is attached to the end surface of the annular sealing boss of the valve seat to form sealing.

2. The soft sealing mechanism for the pressure tap according to claim 1, wherein: the guide rod part of the push rod shaft is provided with a blind hole on the end surface, and a radial through hole is arranged on the excircle and is connected with the blind hole.

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