Safety valve for water vapor

Abstract

According to the technical scheme, the safety valve is characterized by comprising a valve body, a valve seat positioned in the valve body, a valve clack capable of abutting against the valve seat, a recoil disc coaxially connected with the valve clack, a valve rod driving the recoil disc to move, an adjusting ring connected to the exterior of the valve seat in a threaded mode and a set screw used for limiting rotation of the adjusting ring. The end face, facing the recoil disc, of the adjusting ring is provided with a pressure storage groove for the recoil disc to partially stretch in, and the diameter of the end, stretching into the pressure storage groove, of the recoil disc is close to the inner diameter of the pressure storage groove. The problems that in the prior art, the lifting force borne by a valve clack and a recoil disc integrally is small, so that the opening efficiency is low, and the valve clack and a valve seat are prone to frequent impact and are prone to damage are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of safety valves, and more particularly to a safety valve for water steam. Background Art

[0002] An existing safety valve for water steam includes a valve body, a valve seat inserted into the valve body, a valve disc capable of contacting the valve seat, a recoil disc coaxially connected to the valve disc, a valve stem connected to the recoil disc, an adjusting ring connected to the valve seat, and a set screw for limiting the rotation of the adjusting ring. The valve disc is made of non-metallic fluoroplastic or other materials and is embedded in the lower end of the recoil disc. The valve disc and the valve seat are sealed in a flat seal. The outer diameter of the adjusting ring is smaller than the diameter of the end face facing the recoil disc. This has a defect. When the medium in the valve seat pushes up the valve disc and the recoil disc as a whole, the medium is rapidly depressurized into the flow channel. The valve disc and the recoil disc move downward under the action of gravity or a spring, causing fluctuations in the opening between the valve disc, the recoil disc, and the valve seat, and unstable medium pressure. As a result, the lift force on the valve disc and the recoil disc as a whole is small and fluctuates, affecting the opening efficiency between the valve disc and the valve seat. At the same time, the valve disc and the valve seat are easily damaged due to frequent collisions. Utility Model Content

[0003] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a safety valve for water steam with large and stable lift.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a safety valve for water steam, comprising a valve body, a valve seat positioned in the valve body, a valve disc capable of contacting the valve seat, a recoil disc coaxially connected to the valve disc, a valve stem for driving the recoil disc to move, an adjustment ring threadedly connected to the outside of the valve seat, and a set screw for limiting the rotation of the adjustment ring, wherein a pressure-maintaining groove for partially extending the recoil disc is provided on the end surface of the adjustment ring facing the recoil disc, and the diameter of the end of the recoil disc extending into the pressure-maintaining groove is similar to the inner diameter of the pressure-maintaining groove.

[0005] As a further improvement of the present invention, the recoil disc and the valve disc are floatingly connected, a first steel ball is arranged between the recoil disc and the valve disc, and a conical centering groove for partially accommodating the first steel ball is provided on the facing surfaces of the recoil disc and the valve disc.

[0006] As a further improvement of the present invention, the recoil disc and the valve stem are floatingly connected, a second steel ball is arranged between the recoil disc and the valve stem, and a conical positioning groove for partially accommodating the second steel ball is provided on the facing surfaces of the recoil disc and the valve stem.

[0007] As a further improvement of the present invention, the edge of the inner cavity opening of the recoil disk facing the adjustment ring is chamfered.

[0008] Advantages of the present utility model: The end of the backflush disc is inserted into the pressure storage groove on the end face of the adjusting ring. Such a design can, compared with the prior art, utilize the pressure storage cavity jointly formed by the pressure storage groove and the inner cavity of the backflush disc to provide a buffer space for the valve flap and the backflush disc as a whole. During the opening process, the lifting force received by the valve flap and the backflush disc as a whole is greater and more stable, improving the opening efficiency of the valve flap and the backflush disc as a whole. During the closing process, the downward movement of the valve flap and the backflush disc as a whole is smoother, effectively reducing the impact force between the valve flap and the valve seat, thereby reducing the degree of collision between the valve flap and the valve seat, and indirectly ensuring the sealing stability between the valve flap and the valve seat. At the same time, whether during the opening or closing process, the pressure change of the medium between the valve flap and the valve seat is small and tends to be gentle, so that the movement of the valve flap and the backflush disc as a whole tends to be smooth and is less affected by the medium pressure fluctuation. Brief Description of the Drawings

[0009] Figure 1 is a schematic structural diagram of the present utility model;

[0010] Figure 2 is Figure 1 an enlarged view of part A in

[0011] Reference numerals: 1, valve body; 2, valve seat; 3, valve flap; 4, backflush disc; 5, valve stem; 6, adjusting ring; 7, set screw; 8, pressure storage groove; 9, first steel ball; 10, centering groove; 11, second steel ball; 12, positioning groove. Detailed Description of the Specific Embodiment

[0012] The present utility model will be further described in detail below with reference to the drawings and embodiments. The same components are denoted by the same reference numerals.

[0013] Referring to Figure 1 and Figure 2 as shown, a safety valve for water steam in this embodiment includes a valve body 1, a valve seat 2 positioned inside the valve body 1, a valve flap 3 capable of abutting against the valve seat 2, a backflush disc 4 coaxially connected to the valve flap 3, a valve stem 5 driving the backflush disc 4 to move, an adjusting ring 6 threadedly connected to the outside of the valve seat 2, and a set screw 7 for restricting the rotation of the adjusting ring 6;

[0014] Based on the aforementioned prior art, a pressure storage groove 8 for partial insertion of the recoil disc 4 is provided on the end face of the adjusting ring 6 facing the recoil disc 4. The diameter of the end of the recoil disc 4 inserted into the pressure storage groove 8 is close to the inner diameter of the pressure storage groove 8. In the initial state, the valve flap 3 abuts against the valve seat 2 to form a hard seal. The end of the recoil disc 4 extends into the inner cavity of the pressure storage groove 8. The inner cavity of the pressure storage groove 8 and the inner cavity of the recoil disc 4 together form a pressure storage cavity. By rotating the adjusting ring 6 relative to the valve seat 2, the adjusting ring 6 moves along the axis of the valve seat 2, and the length of the recoil disc 4 inserted into the pressure storage groove 8 changes accordingly, thereby changing the opening and closing pressure difference between the recoil disc 4 and the adjusting ring 6. After the adjusting ring 6 rotates in place, the end of the set screw 7 is inserted into the groove on the circumferential wall of the adjusting ring 6 to prevent the adjusting ring 6 from rotating; during use, the medium in the inner cavity of the valve seat 2 pushes the valve flap 3 and the recoil disc 4 upwards as a whole, the valve flap 3 separates from the valve seat 2, and the recoil disc 4 does not come out of the pressure storage groove 8. At this time, the speed of the medium entering the pressure storage cavity is greater than the speed of the medium flowing out of the pressure storage groove 8, and the medium quickly fills the pressure storage cavity. The overall height change of the valve flap 3 and the recoil disc 4 is small. After the pressure storage cavity is filled, the lift force generated by the medium on the valve flap 3 and the recoil disc 4 as a whole is large and stable, and the valve flap 3 and the recoil disc 4 as a whole move upwards quickly and smoothly. The recoil disc 4 disengages from the pressure storage groove 8 until the speed of the medium flowing into the pressure storage cavity is equal to the speed of the medium flowing from the pressure storage cavity into the valve body 1, and the overall height of the valve flap 3 and the recoil disc 4 remains constant, and the valve flap 3 and the recoil disc 4 as a whole are opened in place relative to the valve seat 2; when the medium pressure in the inner cavity of the valve seat 2 decreases or disappears, the valve flap 3 and the recoil disc 4 as a whole move downwards smoothly, and the medium in the pressure storage cavity continues to flow into the valve body 1 until the valve flap 3 abuts against the valve seat 2 again to form a seal, and the end of the recoil disc 4 is inserted into the pressure storage groove 8 again;

[0015] Such a design can, compared with the prior art, use the pressure storage cavity formed by the pressure storage groove 8 and the inner cavity of the recoil disc 4 to provide a buffer space for the valve flap 3 and the recoil disc 4 as a whole. During the opening process, the lift force received by the valve flap 3 and the recoil disc 4 as a whole is greater and more stable, improving the opening efficiency of the valve flap 3 and the recoil disc 4 as a whole. During the closing process, the downward movement of the valve flap 3 and the recoil disc 4 as a whole is smoother, effectively reducing the impact force between the valve flap 3 and the valve seat 2, thereby reducing the degree of collision between the valve flap 3 and the valve seat 2, and indirectly ensuring the sealing stability between the valve flap 3 and the valve seat 2. At the same time, during both the opening and closing processes, the pressure change of the medium between the valve flap 3 and the valve seat 2 is small and tends to be gentle, so that the movement of the valve flap 3 and the recoil disc 4 as a whole tends to be smooth and is less affected by the medium pressure fluctuation.

[0016] As a specific implementation of the improvement, referring to Figure 2As shown, a floating rod is coaxially arranged on the valve flap 3. The peripheral wall of the end of the floating rod that is not connected to the valve flap 3 is machined with an external thread, and the major diameter of the external thread is greater than the diameter of the floating rod. A floating groove for the floating rod to penetrate is provided on the backflush disc 4. The shape of the vertical plane where the floating groove is located is T-shaped, and the part with a smaller diameter is machined with an internal thread that can match the external thread. Both the end face of the floating rod and the bottom of the floating groove are provided with centering grooves 10 with a tapered inner cavity. During the assembly process, the first steel ball 9 is placed at the centering groove 10 on the end face of the floating rod. Then, the valve flap 3 is moved towards the backflush disc 4 so that the end of the floating rod abuts against the port of the floating groove. Next, the valve flap 3 is rotated relative to the backflush disc 4 so that the floating rod is screwed into the floating groove until the external thread of the floating rod is separated from the internal thread of the floating groove. Then, the valve flap 3 is limited within the backflush disc 4 and the valve flap 3 can move slightly up and down relative to the backflush disc 4. The first steel ball 9 is limited between the two centering grooves 10. During the closing process, the valve flap 3 is subjected to an upward thrust from the medium and jointly clamps the first steel ball 9 with the backflush disc 4. The valve flap 3 adjusts its position on the horizontal plane relative to the first steel ball 9, thereby ensuring that the backflush disc 4, the first steel ball 9, and the valve flap 3 are all on the same axis, indirectly ensuring that the sealing surface of the valve flap 3 is coaxial with the sealing surface of the valve seat 2 and realizing effective sealing between the valve flap 3 and the valve seat 2.

[0017] As a specific embodiment of the improvement, refer to Figure 2 As shown, the peripheral wall of the end of the valve stem 5 connected to the backflush disc 4 is machined with an external thread, and the major diameter of the external thread is greater than the diameter of the end of the valve stem 5. A groove for the end of the valve stem 5 to penetrate is provided on the backflush disc 4. The shape of the vertical plane where the groove is located is T-shaped, and the part with a smaller diameter is machined with an internal thread that can match the external thread. Both the end face of the valve stem 5 and the bottom of the groove are provided with positioning grooves 12 with a tapered inner cavity. During the assembly process, the second steel ball 11 is placed in the groove. The second steel ball 11 stops in the positioning groove 12 under the action of gravity and is coaxial with the backflush disc 4. Then, the valve stem 5 is moved towards the backflush disc 4 so that the end of the valve stem 5 abuts against the port of the groove. Next, the valve stem 5 is rotated relative to the backflush disc 4 so that the end of the valve stem 5 is screwed into the groove until the external thread of the valve stem 5 is separated from the internal thread of the groove. Then, the end of the valve stem 5 is limited within the backflush disc 4 and the valve stem 5 can move slightly up and down relative to the backflush disc 4. The second steel ball 11 is limited between the two positioning grooves 12. During the closing process, the valve flap 3 and the backflush disc 4 as a whole are subjected to an upward thrust from the medium. The valve stem 5 and the backflush disc 4 jointly clamp the second steel ball 11. The backflush disc 4 adjusts its position on the horizontal plane relative to the second steel ball 11, thereby ensuring that the backflush disc 4, the first steel ball 9, and the valve stem 5 are all on the same axis, and the coaxiality between the valve stem 5 and the backflush disc 4 is high.

[0018] As a specific embodiment of the improvement, refer to Figure 2As shown in the figure, the backflush disc 4 is chamfered at the opening edge of the inner cavity facing the adjusting ring 6. Such a design can further increase the volume of the pressure storage cavity jointly formed by the backflush disc 4 and the pressure storage groove 8, thereby slowing down the influence of the change of the medium pressure inside the valve seat 2 on the change of the medium pressure inside the pressure storage cavity, further reducing the pressure fluctuation of the medium inside the pressure storage cavity, and ensuring that the overall movement of the valve flap 3 and the backflush disc 4 is in a smooth state.

[0019] The above description is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A safety valve for steam, comprising a valve body (1), a valve seat (2) positioned within the valve body (1), a valve disc (3) capable of abutting against the valve seat (2), a reaction disc (4) coaxially connected to the valve disc (3), a valve stem (5) driving the reaction disc (4) to move, an adjusting ring (6) threadedly connected to the outside of the valve seat (2), and a set screw (7) for restricting the rotation of the adjusting ring (6), characterized in that: A pressure accumulating groove (8) for partial insertion of the backflush disc (4) is provided on the end face of the adjusting ring (6) facing the backflush disc (4), and the diameter of the end of the backflush disc (4) inserted into the pressure accumulating groove (8) is close to the inner diameter of the pressure accumulating groove (8).

2. The safety valve for water vapor according to claim 1, wherein: The backflush disc (4) is floatingly connected to the valve flap (3), a first steel ball (9) is arranged between the backflush disc (4) and the valve flap (3), and centering grooves (10) which are conical and for partial accommodation of the first steel ball (9) are arranged on the opposite faces of the backflush disc (4) and the valve flap (3).

3. A safety valve for steam, according to claim 1 or 2, characterized in that: The backflush disc (4) is floatingly connected to the valve stem (5), a second steel ball (11) is arranged between the backflush disc (4) and the valve stem (5), and positioning grooves (12) which are conical and for partial accommodation of the second steel ball (11) are arranged on the opposite faces of the backflush disc (4) and the valve stem (5).

4. A safety valve for water vapor according to claim 1 or 2, characterized in that: The edge of the inner cavity opening of the backflush disc (4) facing the adjusting ring (6) is chamfered obliquely.

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