Anti-siphon valve

Abstract

The object of the present invention is to provide an anti-siphon valve with a low valve opening pressure. To achieve the above object, the present invention adopts the following technical scheme: an anti-siphon valve, comprising a valve body with an inner cavity, the valve body forming an inner cavity of the valve body, the valve body forming a liquid inlet and a liquid outlet connected to the inner cavity of the valve body, a valve stem is provided in the valve body, a valve plate is fixed to the upper end of the valve stem, a sealing assembly is fixed to the lower end of the valve stem, the sealing assembly divides the inner cavity of the valve body into a first inner cavity and a second inner cavity, the liquid passes through the liquid inlet, the first inner cavity, and the liquid outlet in turn to be discharged from the valve body, the second inner cavity is connected to the atmosphere, the valve plate moves upward to open the liquid outlet, the valve plate moves downward to close the liquid outlet, and when the liquid inlet is filled with liquid so that the first inner cavity is filled with liquid, the force area of ​​the sealing assembly is greater than the force area of ​​the valve plate.

Description

Technical Field

[0001] The invention relates to an anti-siphon valve used in a refueling system of an above-ground oil storage tank or a skid-mounted tank and matched with a self-priming refueling machine. Background Art

[0002] At present, the finished fuel industry uses various types of above-ground oil storage tanks during the oil product transfer and transmission process. To ensure the safety of fuel stored in the tanks, anti-siphon valves are installed in the oil outlet pipeline. When the outlet valve on the oil outlet pipe fails or any part of the pipeline is broken, the anti-siphon valve can overcome the siphon phenomenon caused by the liquid level difference and avoid economic losses and environmental pollution caused by fuel leakage.

[0003] The existing anti-siphon valve includes a compression spring and a valve piston in the opposite direction of the siphon direction. The spring force is greater than the siphon pressure under the condition of the highest liquid level difference (F > ΔH∙ρ∙g∙S) to prevent fuel from leaking through the anti-siphon valve. When the self-priming pump (self-priming fuel dispenser) downstream of the oil outlet pipeline is started, the negative pressure generated by the pump needs to overcome the difference between the spring force and the siphon pressure before the anti-siphon valve can be opened to achieve fuel transmission. The spring strength of the anti-siphon valve needs to match the applicable ground oil tank and fueling system. The spring force is sufficient to overcome the siphon pressure generated when the liquid level in the tank is at the highest point; but when the liquid level in the tank is at the lowest point, the siphon pressure decreases, while the spring force remains unchanged. At this time, the valve opening pressure of the anti-siphon valve increases, that is, the liquid resistance upstream of the self-priming pump increases, limiting the system flow. Summary of the invention

[0004] The object of the present invention is to provide an anti-siphon valve with a low valve opening pressure.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an anti-siphon valve, comprising a valve body with an inner cavity, the valve body forming a valve body inner cavity, the valve body forming a liquid inlet and a liquid outlet connected to the valve body inner cavity, the valve body is provided with a valve stem, a valve plate is fixed to the upper end of the valve stem, a sealing assembly is fixed to the lower end of the valve stem, the sealing assembly divides the valve body inner cavity into a first inner cavity and a second inner cavity, liquid passes through the liquid inlet, the first inner cavity, and the liquid outlet in sequence to be discharged from the valve body, the second inner cavity is connected to the atmosphere, the valve plate moves upward to open the liquid outlet, the valve plate moves downward to close the liquid outlet, and when liquid is introduced into the liquid inlet so that the first inner cavity is filled with liquid, the force area of ​​the sealing assembly is greater than the force area of ​​the valve plate.

[0006] Since the pressure on the sealing component is greater than the pressure on the valve plate, the sealing component will move the valve stem downward to allow the valve plate to seal the liquid outlet, so that the valve of the present invention has an anti-siphon function; when the oil tank needs to discharge oil, the self-priming pump is turned on to create a negative pressure at the liquid outlet of the valve body. Since the second inner cavity of the valve body is connected to the atmosphere, the sealing component and the valve stem will move upward under the action of atmospheric pressure to allow the valve plate to open the liquid outlet. The smaller the difference between the pressure area of ​​the sealing component and the pressure area of ​​the valve plate, the smaller the power required by the self-priming pump to generate the negative pressure, and the valve opening pressure provided by the self-priming pump will be constant and independent of the siphon pressure. The oil tank using the valve of the present invention can use a self-priming pump with less power and can ensure smooth oil discharge.

[0007] Preferably, a compression spring is provided in the first inner cavity, the compression spring is sleeved on the valve stem, the valve body has a fixing portion located on the axial side of the compression spring, one axial end of the compression spring abuts against the fixing portion, and the other axial end of the compression spring abuts against the sealing assembly.

[0008] The setting of the compression spring can always keep the valve plate sealed to the liquid outlet when the anti-siphon valve is installed, and can keep the valve plate sealed to the liquid outlet when there is no oil or little oil in the oil tank. Among them, a weak spring can be used to reduce the burden of the self-priming pump.

[0009] Preferably, the sealing assembly comprises a diaphragm, the circumferential outer edge of the diaphragm is fixed to the valve body, and the middle portion of the diaphragm is fixed and linked to the valve stem.

[0010] The setting of the diaphragm can reduce the damping of the axial movement of the valve stem, so as to further reduce the valve opening pressure to be generated by the self-priming pump.

[0011] Preferably, the valve plate is provided with a pressure relief hole which passes through from top to bottom, and a thermal expansion pressure relief valve is provided in the pressure relief hole.

[0012] Under high temperature conditions, the fuel in the oil circuit will expand due to the temperature increase, which may cause the oil outlet pipe of the oil tank to be over-pressured and damaged or damage the downstream components of the oil outlet pipe. The thermal expansion pressure relief valve of the present invention will open at a higher temperature to divert the fuel back to the oil tank to protect the oil outlet pipe and downstream components. According to actual needs, a suitable thermal expansion pressure relief valve is selected so that the thermal expansion pressure relief valve will open at a fixed pressure.

[0013] Preferably, the liquid outlet is a structure with an inner diameter gradually decreasing from top to bottom, the valve plate includes an upper valve plate and a lower valve plate, at least the lower valve plate is a structure with an outer diameter gradually decreasing from top to bottom, a sealing ring is provided between the lower valve plate and the liquid outlet, and the sealing ring is fixed to the valve body or the valve plate; the outer diameter of the upper valve plate is larger than the inner diameter of the liquid outlet and the outer diameter of the lower valve plate.

[0014] The design of the liquid outlet and the valve plate improves the sealing effect. The design of the upper outer diameter of the valve plate being larger than the lower outer diameter of the valve plate is used to limit the movement of the valve stem to prevent the valve plate from passing downward through the liquid outlet.

[0015] Preferably, the sealing assembly further includes a first pressure block and a second pressure block, the diaphragm, the first pressure block and the second pressure block are all formed with a central hole that matches the valve stem, the first pressure block and the second pressure block are fixed to the valve stem, the middle part of the diaphragm is confined between the first pressure block and the second pressure block, the first pressure block is located in the first chamber, and the second pressure block is located in the second chamber.

[0016] The above arrangement makes it more convenient to fix and link the diaphragm and the valve stem.

[0017] Preferably, the valve stem is composed of an upper valve stem section, a middle valve stem section and a lower valve stem section, the diameter of the middle valve stem section is larger than the diameter of the upper valve stem section and the diameter of the lower valve stem section, the valve plate is formed with a threaded structure matching the upper valve stem section, the center hole of the first pressure block is a through hole, the center hole of the second pressure block is a threaded hole and forms a threaded structure matching with the lower valve stem section, when the two ends of the valve stem are respectively threadedly fixed to the valve plate and the second pressure block, the step surface formed by the middle valve stem section and the upper valve stem section contacts the lower end surface of the valve plate, and the step surface formed by the middle valve plate section and the lower valve stem section contacts the upper end surface of the first pressure block; the valve body includes an upper valve body and a lower valve body, and the circumferential outer edge of the diaphragm is clamped and fixed between the lower end surface of the upper valve body and the upper end surface of the lower valve body.

[0018] The above arrangement makes the assembly of the valve parts simpler and more convenient.

[0019] Preferably, the fixing portion is provided with a guide hole penetrating vertically, and the valve stem is slidably fitted in the guide hole.

[0020] The fixing part is not only used to support the compression spring, but also to guide the valve stem to prevent the lower end of the valve stem from shaking. The thickness of the fixing part is set according to actual needs to prevent the valve stem from tilting relative to the valve body axis. The fixing part has a certain thickness and can also be used as the upper limit of the sealing component to prevent the compression spring from being over-compressed or the diaphragm from being torn.

[0021] Preferably, the valve body includes an upper valve body section, a middle valve body section and a lower valve body section in the axial direction, the valve plate is located in the upper valve body section, the liquid outlet is provided between the upper valve body section and the middle valve body section, the liquid inlet is provided in the middle valve body section, a plurality of liquid inlets are evenly spaced and arranged in an annular shape on the circumferential valve wall of the middle valve body section, and the sealing assembly is arranged in the lower valve body section. The above arrangement makes the valve structure of the present invention simpler.

[0022] Preferably, the sealing assembly is formed with a lower protrusion extending upward, the fixing portion is formed with an upper protrusion extending downward, and both ends of the compression spring are respectively sleeved on the circumferential outer sides of the upper protrusion and the lower protrusion.

[0023] The invention has the advantage of making the valve opening pressure small and constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A cross-sectional view of the present invention

[0025] Figure 2 A schematic diagram of the structure of the valve body of the present invention;

[0026] Figure 3 A cross-sectional view of the valve body of the present invention

[0027] Figure 4 It is a structural schematic diagram of the valve stem of the present invention.

[0028] Among them, 10-upper valve body; 20-lower valve body; 101-upper section of valve body, 102-middle section of valve body; 103-lower section of valve body; 104-fixed part; 11-liquid inlet; 12-liquid outlet; 13-first inner cavity; 14-second inner cavity; 15-connecting hole; 16-connecting pipeline; 17-upper protrusion; 2-valve stem; 21-upper section of valve stem; 22-middle section of valve stem; 23-lower section of valve stem; 3-valve plate; 31-pressure relief hole; 32-sealing ring; 301-upper section of valve plate; 302-lower section of valve plate; 4-compression spring; 5-diaphragm, 6-first pressure block; 61-lower protrusion; 7-second pressure block; 8-thermal expansion pressure relief valve. DETAILED DESCRIPTION

[0029] The present invention will be further described below based on the accompanying drawings and specific embodiments.

[0030] The anti-siphon valve of the present invention is used in a refueling system of an above-ground oil storage tank or a skid-mounted tank and is matched with a self-priming refueling machine.

[0031] Depend on Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, the anti-siphon valve of the present invention includes a valve body with an inner cavity, the valve body is formed with an inner cavity of the valve body, a liquid inlet 11 and a liquid outlet 12 connected to the inner cavity of the valve body are formed on the valve body, a valve stem 2 is provided in the valve body, a valve plate 3 is fixed to the upper end of the valve stem 2, a sealing assembly is fixed to the lower end of the valve stem 2, the sealing assembly divides the inner cavity of the valve body into a first inner cavity 13 and a second inner cavity 14, liquid (fuel) passes through the liquid inlet 11, the first inner cavity 13, and the liquid outlet 12 in sequence to be discharged from the valve body, the second inner cavity 14 is connected to the atmosphere, the valve plate 3 moves upward to open the liquid outlet 12, and the valve plate 3 moves downward to close the liquid outlet 12, when liquid is introduced into the liquid inlet 11 to fill the first inner cavity 13 with liquid, the force area of ​​the sealing assembly is larger than the force area of ​​the valve plate 3.

[0032] The valve body of the present invention includes an upper valve body section 101, a middle valve body section 102 and a lower valve body section 103 in the axial direction, the valve plate 3 is located in the upper valve body section 101, the liquid outlet 12 is provided between the upper valve body section 101 and the middle valve body section 102, the middle valve body section 102 is provided with a plurality of liquid inlets 11, the plurality of liquid inlets 11 are evenly spaced in an annular shape on the circumferential valve wall of the middle valve body section 102, and the sealing assembly is arranged in the lower valve body section 103. A connecting hole 15 is opened on the circumferential valve wall of the lower valve body section 103, and the connecting hole 15 is communicated with the second inner cavity 14.

[0033] A fixing part 104 is provided between the middle section 102 and the lower section 103 of the valve body. The fixing part 104 is provided with a plurality of connecting pipes 16 that connect the first inner cavity of the middle section 102 of the valve body with the first inner cavity of the lower section 103 of the valve body. A compression spring 4 is provided in the first inner cavity of the lower section 103 of the valve body. The compression spring 4 is sleeved on the valve stem 2. The fixing part 104 is located on the axial upper side of the compression spring 4. The sealing assembly is located on the axial lower side of the compression spring 4. One axial end of the compression spring 4 abuts against the fixing part 104, and the other axial end of the compression spring 4 abuts against the sealing assembly. A guide hole 18 is provided at the center of the fixing part 104 and runs through it from top to bottom. The valve stem 2 is slidably fitted in the guide hole 18.

[0034] The sealing assembly includes a diaphragm 5, a first pressure block 6 and a second pressure block 7. The diaphragm 5, the first pressure block 6 and the second pressure block 7 are all formed with a central hole that matches the valve stem 2. The first pressure block 5 and the second pressure block 6 are fixed to the valve stem 2. The circumferential outer edge of the diaphragm 5 is fixed to the valve body, and the middle of the diaphragm 5 is fixed and linked to the valve stem 2. The middle of the diaphragm 5 is confined between the first pressure block 5 and the second pressure block 6. The first pressure block 5 is located in the first chamber 13, and the second pressure block 6 is located in the second chamber 14. Among them, the diaphragm of this embodiment is made of rubber or latex material. The first pressure block 5 is formed with a lower protrusion 61 extending upward, and the fixing portion 104 is formed with an upper protrusion 17 extending downward. The two ends of the compression spring 4 are respectively arranged on the circumferential outer sides of the upper protrusion 17 and the lower protrusion 61.

[0035] The valve stem 2 is composed of an upper valve stem section 21, a middle valve stem section 22 and a lower valve stem section 23. The diameter of the middle valve stem section 22 is larger than the diameter of the upper valve stem section 21 and the diameter of the lower valve stem section 23. The valve plate 3 is formed with a threaded structure matching the upper valve stem section 21. The center hole of the first pressing block 6 is a through hole, and the center hole of the second pressing block 7 is a threaded hole and forms a threaded structure matching with the lower valve stem section 23. When the two ends of the valve stem 2 are respectively threadedly fixed to the valve plate 3 and the second pressing block 7, the step surface formed by the middle valve stem section 22 and the upper valve stem section 21 contacts the lower end surface of the valve plate 3, and the step surface formed by the middle valve plate section 22 and the lower valve stem section 23 contacts the upper end surface of the first pressing block 6. The valve body includes an upper valve body 10 and a lower valve body 20. The circumferential outer edge of the diaphragm 5 is clamped and fixed between the lower end surface of the upper valve body 10 and the upper end surface of the lower valve body 20. The upper valve body 10 and the lower valve body 20 are locked and fixed together by fasteners. The upper valve body section 101 , the middle valve body section 102 and part of the lower valve body section constitute the upper valve body 10 , and another part of the lower valve body section constitutes the lower valve body 20 .

[0036] The valve plate 3 is provided with a pressure relief hole 31 which runs through from top to bottom, and a thermal expansion pressure relief valve 8 is provided in the pressure relief hole 31. The liquid outlet 12 is a structure with a gradually decreasing inner diameter from top to bottom, and the valve plate 3 includes a valve plate upper portion 301 and a valve plate lower portion 302, and the valve plate lower portion 302 is a structure with a gradually decreasing outer diameter from top to bottom, and a sealing ring 32 is provided between the valve plate lower portion 302 and the liquid outlet 12, and the sealing ring 32 is sleeved and fixed on the circumference of the valve plate lower portion 302, and the maximum outer diameter of the valve plate upper portion 301 is greater than the maximum inner diameter of the liquid outlet 12 and the maximum outer diameter of the valve plate lower portion 302.

[0037] Since the force-bearing area of ​​the sealing component is larger than the force-bearing area of ​​the valve plate, the sealing component will be driven by the liquid pressure to move the valve stem downward, so that the valve plate can seal the liquid outlet of the valve of the present invention. Regardless of the liquid level in the oil tank, the valve plate can always close the oil outlet. Since the present invention is provided with a compression spring, under the action of the compression spring, the sealing component always has a tendency to move downward, and is assisted by the compression spring to ensure the sealing effect of the valve plate on the liquid outlet. The self-priming pump in the refueling system of the present invention only needs to generate a small negative pressure downstream of the valve body outlet to enable the oil in the valve body to push the valve plate up, and the opening pressure required by the self-priming pump to open the anti-siphon valve is relatively small. The present invention has the advantage of making the valve opening pressure small and constant.

Claims

1. An anti-siphon valve, characterized in that 2. The closure of the present invention as claimed in claim 1, wherein the closure of the present invention is a valve body having an inner cavity, wherein a liquid inlet and a liquid outlet communicating with the inner cavity of the valve body are formed on the valve body, a valve stem is arranged in the valve body, a valve plate is fixed to the upper end of the valve stem, a sealing assembly is fixed to the lower end of the valve stem, the sealing assembly divides the inner cavity of the valve body into a first inner cavity and a second inner cavity, liquid passes through the liquid inlet, the first inner cavity and the liquid outlet in sequence to be discharged from the valve body, the second inner cavity is connected to the atmosphere, the valve plate moves upward to open the liquid outlet, and the valve plate moves downward to close the liquid outlet, and when liquid is introduced into the liquid inlet so that the first inner cavity is filled with liquid, the force-bearing area of ​​the sealing assembly is greater than the force-bearing area of ​​the valve plate; the sealing assembly comprises a diaphragm, the circumferential outer edge of the diaphragm is fixed to the valve body, and the middle part of the diaphragm is fixed to and linked with the valve stem; the sealing assembly also comprises a first pressing block and a second pressing block, the diaphragm, the first The pressure block and the second pressure block are both formed with a center hole that matches the valve stem, the first pressure block and the second pressure block are fixed to the valve stem, the middle part of the diaphragm is restricted between the first pressure block and the second pressure block, the first pressure block is located in the first chamber, and the second pressure block is located in the second chamber; a compression spring is provided in the first inner chamber, the compression spring is sleeved on the valve stem, the valve body has a fixing portion located on the axial side of the compression spring, one axial end of the compression spring abuts against the fixing portion, and the other axial end of the compression spring abuts against the sealing assembly; the liquid outlet is a structure in which the inner diameter gradually decreases from top to bottom, the valve plate includes an upper valve plate and a lower valve plate, at least the lower valve plate is a structure in which the outer diameter gradually decreases from top to bottom, a sealing ring is matched between the lower valve plate and the liquid outlet, and the sealing ring is fixed to the valve body or the valve plate; the outer diameter of the upper valve plate is larger than the inner diameter of the liquid outlet and the outer diameter of the lower valve plate.

2. The anti-siphon valve according to claim 1, characterized in that The valve plate is provided with a pressure relief hole which passes through from top to bottom, and a thermal expansion pressure relief valve is provided in the pressure relief hole.

3. The anti-siphon valve according to claim 1, characterized in that The valve stem is composed of an upper valve stem section, a middle valve stem section and a lower valve stem section. The diameter of the middle valve stem section is larger than the diameter of the upper valve stem section and the diameter of the lower valve stem section. The valve plate is formed with a threaded structure that matches the upper valve stem section. The center hole of the first pressure block is a through hole. The center hole of the second pressure block is a threaded hole and forms a threaded structure that matches with the lower valve stem section. When the two ends of the valve stem are respectively threadedly fixed to the valve plate and the second pressure block, the step surface formed by the middle valve stem section and the upper valve stem section contacts the lower end surface of the valve plate, and the step surface formed by the middle valve plate section and the lower valve stem section contacts the upper end surface of the first pressure block. The valve body includes an upper valve body and a lower valve body, and the circumferential outer edge of the diaphragm is clamped and fixed between the lower end surface of the upper valve body and the upper end surface of the lower valve body.

4. The anti-siphon valve according to claim 1, characterized in that The fixing portion is provided with a guide hole which passes through the fixing portion up and down, and the valve stem is slidably fitted in the guide hole.

5. The anti-siphon valve according to claim 1, characterized in that The valve body includes an upper valve body section, a middle valve body section and a lower valve body section in the axial direction, the valve plate is located in the upper valve body section, the liquid outlet is provided between the upper valve body section and the middle valve body section, the liquid inlet is provided in the middle valve body section, a plurality of liquid inlets are evenly spaced in an annular shape on the circumferential valve wall of the middle valve body section, and the sealing assembly is provided in the lower valve body section.

6. The anti-siphon valve according to claim 1, characterized in that The sealing component is formed with a lower protrusion extending upward, the fixing portion is formed with an upper protrusion extending downward, and two ends of the compression spring are respectively sleeved on the circumferential outer sides of the upper protrusion and the lower protrusion.

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