A method and structure for preventing valve stem sealing ring from falling off

Abstract

The present invention discloses a method and structure for preventing a valve stem sealing ring from falling off. The present invention comprises a sleeve (4) being placed over a valve stem (3), and a sleeve hole (7) having the same inner diameter as a valve port (8) being provided at one end of the sleeve (4); when firing, after the sealing ring (1) at the end of the valve stem (3) exits the valve port (8), it first enters the sleeve hole (7), and then the valve stem (3) and the sleeve (4) synchronously move toward the air chamber (10), and separate from the end surface (11) of the valve port (8) to fire a sound source control valve; since the sealing ring (1) is always in a compressed state during the entire firing process, the high-pressure gas is prevented from squeezing or blowing off the sealing ring (1) from the sealing groove at the end of the valve stem (3). The sealing ring on the valve stem of the present invention is always kept in a compressed state, thereby solving the problem of the sealing ring falling out of the valve stem sealing groove and improving the applicability and reliability of the instrument.

Description

Technical Field

[0001] The invention relates to a method and a structure for preventing a valve stem sealing ring from falling off, and belongs to the technical field of oil well liquid level depth testing equipment. Background Art

[0002] The wellhead connector is a device for emitting and receiving sound waves for testing the oil well liquid level in the oil field production process. The depth of the oil well liquid level can be calculated by receiving and processing the sound waves. The mechanism that generates sound waves in the wellhead connector is the sound source control valve. The sound source control valve isolates the air chamber and the casing gas through the valve stem. During the test, the limit pull rod of the valve stem is opened, and the valve stem moves axially under the action of the spring force and gas pressure, and a pulse sound signal is emitted by using the pressure difference between the air chamber and the casing. The pressure range of conventional oil well casing pressure is (0~10MPa). The valve stem of the sound source control valve is generally sealed with a sealing ring. When the sound source control valve is fired, the valve stem moves out of the valve port quickly. When the casing gas pressure exceeds 5MPa and the air is deflated and fired, the sealing ring on the valve stem falls off from the sealing groove; when the pressure is higher, the sealing ring even breaks, causing the valve stem to be unable to reset and seal, making the instrument unable to work properly. Summary of the invention

[0003] The purpose of the present invention is to provide a method and structure for preventing a valve stem sealing ring from falling off, so as to solve the problem of the sealing ring falling out of the valve stem sealing groove and improve the applicability and reliability of the instrument, thereby overcoming the shortcomings of the prior art.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] The present invention provides a method for preventing a valve stem sealing ring from falling off. The method comprises the following steps: a sliding sleeve is arranged on the valve stem outer sleeve, and a sliding sleeve hole having the same inner diameter as the valve port is arranged at one end of the sliding sleeve. When firing, the sealing ring at the end of the valve stem first enters the sliding sleeve hole after withdrawing from the valve port, and then the valve stem and the sliding sleeve synchronously move toward the air chamber direction, and separate from the end face of the valve port to fire the sound source control valve. Since the sealing ring is always in a compressed state during the entire firing process, the high-pressure gas is prevented from squeezing or blowing off the sealing ring from the sealing groove at the end of the valve stem.

[0006] A structure for preventing a valve stem sealing ring from falling off of the present invention, which is constructed according to the above method and used for the above method, includes a valve stem, a sealing groove is provided at the front end of the valve stem, and a sealing ring is provided in the sealing groove; a sliding sleeve is provided outside the valve stem; a sliding sleeve hole is provided at the front end of the sliding sleeve, and the sealing ring at the front end of the valve stem passes through the sliding sleeve hole and extends into the valve port of the joint; a waist-shaped hole is provided on the sliding sleeve; a pin is provided on the valve stem, and the pin is slidably connected to the waist-shaped hole on the sliding sleeve; a spring is provided between the valve stem and the sliding sleeve.

[0007] Due to the adoption of the above technical solution, the sealing ring on the valve stem of the present invention always remains in a compressed state, which solves the problem of the sealing ring falling out of the valve stem sealing groove and improves the applicability and reliability of the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of the structure of the present invention;

[0009] Figure 2 It is a schematic diagram of the application position of the present invention;

[0010] Figure 3 It is a schematic diagram of the application of the prior art.

[0011] Markings in the accompanying drawings are: 1-seal ring, 2-connector, 3-valve stem, 4-sleeve, 5-spring, 6-pin, 7-sleeve hole, 8-valve port, 9-waist-shaped hole, 10-air chamber, 11-valve port end face, 12-existing valve stem. DETAILED DESCRIPTION

[0012] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0013] A method for preventing a valve stem sealing ring from falling off according to the present invention is as follows: Figure 1 and Figure 2 As shown, the method is to put a sliding sleeve 4 on the outer sleeve of the valve stem 3, and one end of the sliding sleeve 4 is provided with a sliding sleeve hole 7 with the same inner diameter as the valve port 8; when firing, when the sealing ring 1 at the end of the valve stem 3 withdraws from the valve port 8, it first enters the sliding sleeve hole 7, and then the valve stem 3 and the sliding sleeve 4 move synchronously toward the air chamber 10, and separate from the valve port end face 11 to fire the sound source control valve; since the sealing ring 1 is always in a compressed state during the entire firing process, the high-pressure gas is prevented from squeezing or blowing the sealing ring 1 out of the sealing groove at the end of the valve stem 3.

[0014] A valve stem sealing ring falling-off prevention structure of the present invention, which is constructed according to the above method and used in the above method, is as follows: Figure 1 and Figure 2 As shown, the structure includes a valve stem 3, a sealing groove is provided at the front end of the valve stem 3, and a sealing ring 1 is provided in the sealing groove; a sleeve 4 is provided on the outer sleeve of the valve stem 3; a sleeve hole 7 is provided at the front end of the sleeve 4, and the sealing ring 1 at the front end of the valve stem 3 passes through the sleeve hole 7 and extends into the valve port 8 of the joint 2; a waist-shaped hole 9 is provided on the sleeve 4; a pin 6 is provided on the valve stem 3, and the pin 6 is slidably connected with the waist-shaped hole 9 on the sleeve 4; a spring 5 is provided between the valve stem 3 and the sleeve 4. Example

[0015] This example is an improvement on the prior art. The prior art sound source control valve is as follows: Figure 3As shown. The sound source control valve isolates the air chamber 10 from the casing gas at the front end of the joint 2 through the existing valve stem 12. During the test, the limit pull rod of the existing valve stem 12 (not shown in the figure) is opened, and the existing valve stem 12 moves axially under the action of the spring force and gas pressure, and uses the pressure difference between the air chamber 10 and the casing to send out a pulse sound signal. The pressure range of conventional oil well casing pressure is (0~10MPa). The valve stem of the sound source control valve is generally sealed with an O-ring. When the sound source control valve is fired, the valve stem quickly moves out of the valve port. When the casing gas pressure exceeds 5MPa and the air is deflated and fired, the O-ring on the valve stem falls off from the sealing groove; when the pressure is higher, the O-ring may even break, causing the valve stem to be unable to reset and seal, making the instrument unable to work properly.

[0016] The improved sound source control valve in this example is as follows Figure 1 and Figure 2 As shown. The improved method is to coat a sleeve 4 on the valve stem 3, and one end of the sleeve 4 is provided with a sleeve hole 7 with the same inner diameter as the valve port 8; when firing, when the sealing ring 1 (the existing O-ring is still used, and the sealing rings mentioned below all refer to O-rings) at the end of the valve stem 3 withdraws from the valve port 8, it first enters the sleeve hole 7, and then the valve stem 3 and the sleeve 4 move synchronously toward the air chamber 10, and leave the valve port end face 11 to fire the sound source control valve; since the sealing ring 1 is always in a compressed state during the entire firing process, it is prevented that the high-pressure gas squeezes out or blows off the sealing ring 1 from the sealing groove at the end of the valve stem 3.

[0017] Specific structure such as Figure 1 As shown. It includes a valve stem 3, a sealing groove is provided at the front end of the valve stem 3, a sealing ring 1 is provided in the sealing groove; a sleeve 4 is provided on the outer cover of the valve stem 3; a sleeve hole 7 is provided at the front end of the sleeve 4, and the sealing ring 1 at the front end of the valve stem 3 passes through the sleeve hole 7 and extends into the valve port 8 of the joint 2; a waist-shaped hole 9 is provided on the sleeve 4; a pin 6 is provided on the valve stem 3, and the pin 6 is slidably connected with the waist-shaped hole 9 on the sleeve 4; a spring 5 is provided between the valve stem 3 and the sleeve 4.

[0018] The working process and principle of the present invention are as follows:

[0019] First, put the spring 5 into the sliding sleeve 4, and then pass the end of the valve stem 3 with the sealing ring 1 through the spring 5 and the sliding sleeve hole 7 of the sliding sleeve 4. Rotate the valve stem 3 to align the pin hole on the valve stem 3 with the waist-shaped hole 9 on the sliding sleeve 4, and then pass the pin 6 through the waist-shaped hole 9 on the sliding sleeve 4 and the pin hole on the valve stem 3. The valve stem 3 can slide axially in the sliding sleeve 4. The sliding stroke is determined by the waist-shaped hole 9. After installation, it should be ensured that when the pin 6 presses against the right end surface of the waist-shaped hole 9 on the sliding sleeve 4, the spring 5 has a certain preload force.

[0020] When the sealing ring 1 at the front end of the valve stem 3 is in the valve port 8 of the joint 2 and is in a sealed state, under the action of the spring 5, the left end face of the sliding sleeve 4 fits with the valve port end face 11, and the spring 5 is in a compressed state. When the sound source control valve is opened, the valve stem 3 moves to the right under the action of the spring force and the casing gas pressure, and the sealing ring 1 at the front end of the valve stem 3 first enters the sliding sleeve hole 7 of the sliding sleeve 4 after withdrawing from the valve port 8. The size of the sliding sleeve hole 7 is the same as that of the valve port 8, so that the sealing ring 1 is still in a compressed state after entering the sliding sleeve hole 7. When the two sealing rings 1 on the valve stem 3 all enter the sliding sleeve hole 7, the pin 6 on the valve stem 3 pushes against the right end face of the waist-shaped hole 9 on the sliding sleeve 4 to drive the sliding sleeve 4 to move to the right together, and the left end face of the sliding sleeve 4 is separated from the valve port end face 11, and the sound source control valve is triggered.

[0021] The sealing ring on the valve stem of the present invention always keeps a compressed state, thus solving the problem of the sealing ring coming out of the valve stem sealing groove and improving the applicability and reliability of the instrument.

Claims

1. A method for preventing a valve stem sealing ring from falling off, characterized in that: The method comprises the following steps: a sleeve (4) is placed on the outer sleeve of a valve stem (3); one end of the sleeve (4) is provided with a sleeve hole (7) having the same inner diameter as the valve port (8); when firing, after the sealing ring (1) at the end of the valve stem (3) exits the valve port (8), it first enters the sleeve hole (7); then the valve stem (3) and the sleeve (4) move synchronously toward the air chamber (10), and separate from the end surface (11) of the valve port (8) to fire the sound source control valve; since the sealing ring (1) is always in a compressed state during the entire firing process, the sealing ring (1) is prevented from being squeezed out of the sealing groove at the end of the valve stem (3) or being blown off by the high-pressure gas.

2. A structure for preventing a valve stem sealing ring from falling off, comprising a valve stem (3), characterized in that: A sealing groove is provided at the front end of the valve stem (3), and a sealing ring (1) is provided in the sealing groove; a sleeve (4) is provided on the outer surface of the valve stem (3); a sleeve hole (7) is provided at the front end of the sleeve (4), and the sealing ring (1) at the front end of the valve stem (3) passes through the sleeve hole (7) and extends into the valve port (8) of the joint (2); a waist-shaped hole (9) is provided on the sleeve (4); a pin (6) is provided on the valve stem (3), and the pin (6) is slidably connected to the waist-shaped hole (9) on the sleeve (4); and a spring (5) is provided between the valve stem (3) and the sleeve (4).

Images