Pressure reducing valve with pressure relief function

Abstract

The application discloses a pressure reducing valve with pressure relief function, which comprises a right valve body and a left valve body which are screwed into one body, a cylindrical slide valve, a spring, a valve seat sleeve and a plurality of sealing rings which are arranged in a valve cavity, the slide valve has a tendency to move leftward under the pressure of the spring, a piston at the left end of the slide valve is pushed by output pressure or pressure in a downstream pipeline, so that the slide valve has a tendency to move rightward, a right end surface of the slide valve and a left end surface of the valve seat sleeve form a valve port of the pressure reducing valve, a center hole of the stepped valve seat sleeve is a water inlet hole, a flat cylinder is arranged at the right end of the slide valve, and the flat cylinder can enter the water inlet hole under the impact of a downstream water hammer, and the left valve body is provided with a pressure relief pipe below a valve body. When an impact wave is generated in the downstream pipeline due to some reasons, high-pressure water in the downstream pipeline is discharged outward through the pressure relief pipe, so that the water pressure in the pipeline is prevented from continuously rising to damage the pipeline, and the absolute safety of the plastic pipeline under the set water pressure can be ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of valves, and particularly relates to a pressure reducing valve with pressure relief function. BACKGROUND

[0002] At present, plastic pipes are used in many occasions for conveying medium. Since the plastic pipes have low pressure-bearing strength, a pressure reducing valve is used in the upstream of the plastic pipes to reduce the high pressure in the upstream. However, when an impact wave is generated in the downstream of the pipes due to some reasons (for example, water hammer generated after a quick closing of a stop valve), the ordinary pressure reducing valve has no pressure relief function, and thus the plastic pipes are often broken due to overpressure. SUMMARY

[0003] The present application aims to solve the problem that the ordinary pressure reducing valve has no pressure relief function, and thus the plastic pipes are easily broken due to overpressure when an impact wave is generated in the downstream of the pipes due to some reasons (for example, water hammer generated after a quick closing of a stop valve), and to provide a pressure reducing valve with pressure relief function. When an impact wave is generated in the downstream of the pipes due to some reasons, the high-pressure water in the downstream pipes is discharged to the outside through the pressure relief pipe, so as to avoid the water pressure in the pipes from continuously rising and damaging the pipes, and to ensure the absolute safety of the plastic pipes under the set water pressure.

[0004] The present application adopts the technical scheme that a pressure reducing valve with pressure relief function comprises a right valve body, the right valve body is integrally screwed with a left valve body, and the center lines are on the same straight line. A cylindrical slide valve, a spring, a valve seat sleeve and a plurality of O-shaped sealing rings are arranged in a valve cavity. The slide valve has a tendency to always move to the left under the pressure of the spring. A piston at the left end of the slide valve is pushed by the output pressure or the pressure in the downstream pipes, so that the slide valve has a tendency to always move to the right. The right end surface of the slide valve and the left end surface of the valve seat sleeve form a valve port of the pressure reducing valve. The center hole of the stepped valve seat sleeve is a water inlet hole. The flat cylinder at the right end of the slide valve can enter the water inlet hole under the impact of the downstream water hammer. The left valve body has a pressure relief pipe below the valve body.

[0005] Further, the right end of the right valve body is a connecting flange, and the left end is a boss. The left end surface of the boss is a limiting surface for the movement of the slide valve. The middle section is a three-step cylinder. An outer thread is arranged on the small cylinder of the three-step cylinder. The middle cylinder is a positioning surface, and is provided with an O-shaped sealing ring. The large cylinder is the outer diameter of the valve body cylinder. The large cylinder has a concave groove with an arc-shaped generatrix at the center. The right end of the concave groove is a stepped hole. The large hole of the stepped hole has an inner thread, and the small hole is a positioning hole. The left end of the concave groove is also a stepped hole. The small hole of the stepped hole is a guide hole. An O-shaped sealing ring is arranged on the inner wall of the guide hole. The center lines of the positioning surface, the positioning hole, the concave groove and the guide hole are on the same straight line with the center line of the right valve body.

[0006] Further, the outer thread on the large diameter of the valve seat sleeve is screwed with the inner thread in the large hole at the right end of the right valve body groove, the small diameter is slidably fitted with the positioning hole, and O-shaped sealing ring three is arranged, and the center hole of the valve seat sleeve is a water inlet hole.

[0007] Further, the left end of the left valve body is a connecting flange, the inner hole is a 5-step stepped hole, the hole diameter of the stepped hole gradually decreases from right to left, the first stepped hole is slidably fitted with the positioning surface of the right valve body, the right side of the second stepped hole has an inner thread, which is screwed with the outer thread on the small cylinder at the left end of the right valve body, the third stepped hole is a guide hole two, a 60-degree taper one is arranged at the transition of the second and third stepped holes, and the hole bottom of the third stepped hole is a limiting surface for the left movement of the slide valve; the small hole at the left end is a water outlet hole; and the lower part has a relief pipe.

[0008] Further, the piston at the left end of the slide valve is movably fitted with the guide hole two, and O-shaped sealing ring four is arranged, a recess for abutting against the spring is arranged at the root of the right side of the piston, the center of the slide valve has a blind hole, the outer circle of the slide valve cylinder is movably fitted with the guide hole one, two notched grooves which are in communication with the blind hole are symmetrically arranged at the right side of the cylinder, the flat cylinder at the right end of the notched groove has a 60-degree taper two, and a flow guide cone is arranged at the right end of the flat cylinder.

[0009] Further, the spring sleeve is arranged on the outer circle of the slide valve cylinder and is positioned between the recess of the slide valve piston and the shoulder of the guide hole one of the right valve body.

[0010] The working principle of the application is as follows: before water is passed, the slide valve is located at the leftmost position under the push of the spring, after water is passed, the water flows through the water inlet hole, the flow guide cone, the valve port, the recess, the notched groove, the blind hole, and then flows out of the water outlet hole to supply water downstream; due to the output pressure P2 acting on the left end surface of the slide valve, the spring pressure is overcome, the slide valve is pushed to move rightward until the force of the spring is balanced, at this time, the opening degree of the valve port is reduced, due to the throttling pressure reduction effect, the output pressure P2 must be smaller than the input pressure P1, and the size of the output pressure P2 depends on the stiffness of the spring, the larger the stiffness of the spring, the larger the opening degree of the valve port, and the larger the output pressure P2; on the contrary, the smaller the stiffness of the spring, the smaller the output pressure P2. When the input pressure P1 increases or the flow decreases, the output pressure P2 also increases, the slide valve is pushed to move rightward, the opening degree of the valve port decreases, the throttling pressure reduction effect increases, and the output pressure P2 decreases accordingly until it returns to the set value. On the contrary, when the input pressure P1 decreases or the flow increases, the output pressure P2 also decreases, the slide valve is pushed to move leftward under the push of the spring, the opening degree of the valve port increases, the throttling pressure reduction effect decreases, and the output pressure P2 increases accordingly until it returns to the original set value.

[0011] When the rear stop valve is closed to stop water supply, the pressure in the water outlet hole and the downstream pipeline gradually increases, the slide valve is pushed to move rightward until the flat cylinder and O-shaped sealing ring five enter the water inlet hole, the passage is cut off, and the pressure of the downstream does not increase any more.

[0012] When the impact wave is caused by the water hammer due to the quick closing of the downstream backstop valve, etc., the impact force acts on the left end face of the slide valve, the impact force overcomes the pressure of the spring, pushes the slide valve to move right quickly until the right end face of the piston contacts the left end face of the right end boss of the right valve body, at this time, the piston has completely separated from the guide hole two, the flat cylinder at the right end of the slide valve and the O-shaped sealing ring five enter the water inlet hole (at this time, the water inlet hole plays the role of the guide hole), the high-pressure water in the downstream pipeline is discharged outward through the pressure relief pipe to relieve pressure, so as to avoid the water pressure in the pipeline to continue to rise and damage the pipeline, and the design of the spring can ensure the absolute safety of the plastic pipeline under the set water pressure.

[0013] The beneficial effects of the present application are that it effectively solves the problem that the ordinary pressure reducing valve in the prior art has no pressure relief function, and when the impact wave is generated in the downstream pipeline due to some reasons (for example, water hammer generated by the quick closing of the backstop valve), the plastic pipeline is prone to overpressure rupture, the pressure reducing valve with pressure relief function in the present application can discharge the high-pressure water in the downstream pipeline outward through the pressure relief pipe to relieve pressure when the impact wave is generated in the downstream pipeline due to some reasons, so as to avoid the water pressure in the pipeline to continue to rise and damage the pipeline, and the absolute safety of the plastic pipeline under the set water pressure can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a structural sectional view of the pressure reducing valve with pressure relief function of the present application;

[0015] Figure 2 is another structural sectional view of the pressure reducing valve with pressure relief function of the present application.

[0016] In the figure: 1. right valve body, 2. valve seat sleeve, 3. O-shaped sealing ring three, 4. O-shaped sealing ring two, 5. spring, 6. slide valve, 7. left valve body, 8. O-shaped sealing ring four, 9. O-shaped sealing ring one, 10. O-shaped sealing ring five, a. positioning face, b. positioning hole, c1. guide hole one, c2. guide hole two, d. boss, e. left end face, f. notch groove, g. flow guide cone, h. blind hole, k1. taper angle one, k2. taper angle two, A. water inlet hole, B. water outlet hole, L. pressure relief pipe, N. groove, V. valve port. DETAILED DESCRIPTION

[0017] The specific implementation of the technical scheme of the present application will be further described below by examples and in combination with the drawings.

[0018] Example 1

[0019] In the like Figure 1In the shown embodiment 1, the pressure relief valve with pressure relief function of the present application is composed of a right valve body 1, a left valve body 7, a slide valve 6, a valve seat sleeve 2, a spring 5 and several O-rings. The right end of the right valve body 1 is a flange, which is connected with the corresponding flange of the upstream water inlet pipe, and the left end is a boss d, the left end face e of which is used to limit the continuous rightward movement of the slide valve 6; the middle section is a three-step cylinder, the small cylinder is externally threaded, the middle cylinder is a positioning surface a, and is provided with an O-ring 9, and the large cylinder is the outer diameter of the cylinder body; the center of the large cylinder has a recess N with an arc-shaped female thread, the right end of the recess N is a stepped hole, the large hole of the stepped hole is internally threaded, and the small hole is a positioning hole b; the left end of the recess N is also a stepped hole, the small hole of which is a guide hole c1 with a certain axial thickness, and the inner wall of the guide hole c1 is provided with an O-ring 2; the center lines of the positioning surface a, the positioning hole b, the recess N and the guide hole c1 are on the same straight line as the center line of the right valve body 1.

[0020] The external thread on the large diameter of the valve seat sleeve 2 is screwed into the internal thread in the large hole at the right end of the recess N of the right valve body 1, the small diameter is slidably fitted with the positioning hole b, and is provided with an O-ring 3, and the center hole of the valve seat sleeve 2 is a water inlet hole A.

[0021] The left end of the left valve body 7 is a connecting flange, which is connected with the corresponding flange of the downstream plastic pipe, the outer diameter of the valve body is consistent with the outer diameter of the valve body of the right valve body 1, and the inner hole is a 5-step stepped hole, the hole diameter of which decreases step by step from right to left, the first stepped hole is slidably fitted with the positioning surface a of the right valve body 1 to ensure that the center lines of the right valve body 1 and the left valve body 7 are consistent; the right side of the second stepped hole is internally threaded and is screwed with the external thread on the small cylinder at the left end of the right valve body 1; the third stepped hole is a guide hole c2, and a 60-degree taper k1 is provided at the transition between the second and third stepped holes to facilitate the entry and exit of the piston at the left end of the slide valve 6 and the O-ring 8; the hole bottom of the third stepped hole is a limiting surface for the leftward movement of the slide valve 6; the small hole at the left end is a water outlet hole B, and the left valve body has a pressure relief pipe L below the valve body.

[0022] The piston at the left end of the slide valve 6 is slidably fitted with the above-mentioned third stepped guide hole c2, and is provided with an O-ring 8, the root of the right side of the piston is provided with a recess for abutting against the spring, the center of the slide valve 6 has a blind hole h, the outer circle of the cylinder body of the slide valve 6 is slidably fitted with the guide hole c1, the right side of the cylinder body is symmetrically provided with two notched grooves f which are communicated with the blind hole, the flat cylinder at the right end of the notched groove f is slidably fitted with the water inlet hole A and is provided with an O-ring 10, the right end of the flat cylinder is provided with a 60-degree taper k2 to facilitate the entry and exit of the flat cylinder and the O-ring 10 into the water inlet hole A, and the right side of the flat cylinder is provided with a flow guide cone g. The right end face of the flat cylinder of the slide valve 6 and the left end face of the valve seat sleeve 2 form the valve port V of the pressure relief valve; the spring 5 is sleeved on the outer circle of the cylinder body of the slide valve 6 and is positioned between the recess of the piston of the slide valve 6 and the shoulder of the guide hole c1 of the valve body 1.

[0023] The working principle of this invention is as follows: Before water is introduced, the slide valve 6 is located at the leftmost position under the push of the spring 5, as shown below. Figure 1 As shown, after water is supplied, water flows through inlet A, guide cone g, valve port V, groove N, notch groove f, and blind hole h, and flows out from outlet B to supply water downstream. Because the output pressure P2 acts on the left end face of slide valve 6, it overcomes the pressure of spring 5, pushing slide valve 6 to the right until it balances with the force of spring 5. At this time, the opening of valve port V decreases. Due to the throttling and pressure reduction effect, the output pressure P2 is necessarily less than the input pressure P1. The magnitude of the output pressure P2 depends on the stiffness of spring 5. A larger stiffness of spring 5 results in a larger opening of valve port V and a larger output pressure P2; conversely, a smaller stiffness of spring 5 results in a smaller output pressure P2. When the input pressure P1 increases or the flow rate decreases, the output pressure P2 also increases, pushing slide valve 6 to the right. The opening of valve port V decreases, the throttling and pressure reduction effect increases, and the output pressure P2 decreases accordingly until it returns to the set value. Conversely, when the input pressure P1 decreases or the flow rate increases, the output pressure P2 also decreases. The slide valve 6 moves to the left under the push of the spring 5, the valve opening V increases, the throttling and pressure reduction effect weakens, and the output pressure P2 increases accordingly until it returns to the original set value.

[0024] When the shut-off valve closes and stops the water supply, the pressure in the outlet B and downstream pipe gradually increases, pushing the slide valve 6 to the right until the flat cylinder and O-ring seal 10 enter the inlet A, cutting off the passage, and the downstream pressure no longer increases.

[0025] When water hammer or other shock waves are generated downstream due to reasons such as the rapid closure of the rear shut-off valve, the impact force acts on the left end face of the slide valve 6, overcoming the pressure of the spring 5 and pushing the slide valve 6 to move rapidly to the right until the right end face of the piston of the slide valve 6 contacts the left end face e of the left end boss d of the right valve body 1. At this time, the piston has completely disengaged from the guide hole c2, and the flat cylinder at the right end of the slide valve 6 and the O-ring seal 10 enter the inlet hole A (at this time, the inlet hole A acts as a guide hole). Figure 2 As shown, the high-pressure water in the downstream pipe is discharged outward from the pressure relief pipe L to relieve pressure and prevent the water pressure in the pipe from continuing to rise and damaging the pipe. The design of the spring 5 in this invention can ensure the absolute safety of the plastic pipe when subjected to the set water pressure.

Claims

1. A pressure-reducing valve with a pressure relief function, characterized in that, Includes a right valve body (1), which is screwed together with the left valve body (7) and the center lines are on the same straight line. The valve cavity is provided with a cylindrical slide valve (6), a spring (5), a valve seat sleeve (2) and several O-rings. The slide valve (6) tends to move to the left under the pressure of the spring (5). The piston at the left end of the slide valve (6) is pushed by the output pressure or the pressure in the downstream pipeline, so that the slide valve (6) tends to move to the right. The right end face of the slide valve (6) and the left end face of the valve seat sleeve (2) form the valve port (V) of the pressure reducing valve. The center hole of the stepped valve seat sleeve (2) is the water inlet (A). The right end of the slide valve (6) is provided with a flat cylinder, which can enter the water inlet (A) under the impact of the downstream water hammer. The left valve body (7) has a pressure relief pipe (L) below the valve body. The left end of the left valve body (7) is a connecting flange, and the inner hole is a 5-step stepped hole, with the diameter of the stepped hole decreasing from right to left.

2. The pressure-reducing valve with pressure relief function according to claim 1, characterized in that, The right end of the right valve body (1) is a connecting flange, and the left end is a boss (d). The left end face (e) of the boss (d) is a limiting surface for the rightward movement of the slide valve (6). The middle section is a three-stage cylinder. The small cylinder of the three-stage cylinder is provided with external threads. The middle cylinder is the positioning surface (a) and is provided with an O-ring seal (9). The large cylinder is the outer diameter of the valve body. There is a groove (N) with an arc-shaped generatrix at the center of the large cylinder. The right end of the groove (N) is a stepped hole. The large hole of the stepped hole has internal threads, and the small hole is the positioning hole (b). The left end of the groove (N) is also a stepped hole. The small hole of the stepped hole is the guide hole (c1). The inner wall is provided with an O-ring seal (4). The center lines of the positioning surface (a), positioning hole (b), groove (N) and guide hole (c1) are on the same straight line as the center line of the right valve body (1).

3. The pressure-reducing valve with pressure relief function according to claim 2, characterized in that, The external thread on the major diameter of the valve seat sleeve (2) is screwed into the internal thread in the large hole at the right end of the groove (N) of the valve body (1), the minor diameter is slidably fitted with the positioning hole (b), and an O-ring seal ring (3) is provided. The center hole of the valve seat sleeve (2) is the water inlet hole (A).

4. The pressure-reducing valve with pressure relief function according to claim 1, characterized in that, The first stepped hole slides into the positioning surface (a) of the right valve body (1); the right side of the second stepped hole has an internal thread that engages with the external thread on the small cylinder at the left end of the right valve body (1); the third stepped hole is the second guide hole (c2), and a 60-degree cone angle (k1) is provided at the transition between the second and third stepped holes; the bottom of the third stepped hole is the limiting surface for the slide valve (6) to move to the left; the small hole at the left end is the water outlet hole (B).

5. The pressure-reducing valve with pressure relief function according to claim 1, characterized in that, The piston at the left end of the slide valve (6) is dynamically matched with the guide hole 2 (c2) and is provided with an O-ring seal 4 (8). The root of the piston on the right side is provided with a groove that abuts against the spring (5). The center of the slide valve (6) has a blind hole (h). The outer circle of the slide valve (6) cylinder is dynamically matched with the guide hole 1 (c1). The right side of the cylinder is symmetrically provided with two notches (f) that communicate with the blind hole (h). The flat cylinder at the right end of the notch (f) is dynamically matched with the inlet (A) and is provided with an O-ring seal 5 (10). The right end of the flat cylinder is provided with a 60-degree cone angle 2 (k2), and the right side of the flat cylinder is provided with a guide cone (g).

6. The pressure-reducing valve with pressure relief function according to claim 1, characterized in that, The spring (5) is sleeved on the outer circle of the slide valve (6) and positioned between the groove of the piston of the slide valve (6) and the shoulder of the guide hole (c1) of the valve body (1).

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