High-pressure direct load balance type back pressure valve

Abstract

The invention discloses a high-pressure direct load balance type back pressure valve, relates to the technical field of back pressure valves, and solves the technical problems that when the opening and closing pressure difference given by the technology is small, the use range of the back pressure valve is almost impossible to be reduced by only depending on the linearity of a spring. A high-pressure direct load balance type back pressure valve comprises an upper valve body, a lower valve body and a pressure sensor, the lower valve body is assembled in front of the upper valve body, a gas balance channel is formed in the lower valve body and the upper valve body, and a sealing ring embedded into the gas balance channel is arranged between the valve seat and the upper valve body; the stepped valve core is assembled in the high-pressure air chamber; appropriate spring force can be selected through calculation, the three-dimensional size of the spring is reduced, meanwhile, the overall three-dimensional size of the valve is reduced, throat diameter limitation is solved, a back pressure valve or a pressure maintaining valve with the large throat diameter can be designed by selecting the spring with the small pressure value, the adjusting precision of the back pressure valve is improved, and the use range of the back pressure valve is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of back pressure valve and pressure holding valve, in particular to a high pressure direct load balanced back pressure valve. In the same valve, if the opening and closing pressure difference Pqb is less than or equal to 10%, the valve is a back pressure valve; if the opening and closing pressure difference Pqb is greater than 10% to 30%, the valve is a pressure holding valve. Background Art

[0002] Direct load balanced back pressure valve is a valve that relies only on direct mechanical loading devices such as hammers, levers and hammers or springs to overcome the force generated by the medium pressure under the valve disc.

[0003] Since the existing traditional direct load back pressure valve uses a spring to indirectly press the valve disc to adjust the opening set pressure, the required spring pressure is proportional to the throat diameter of the sealing surface. When the input set pressure is large and the throat diameter of the valve seat sealing surface is large, the required spring pressure is large and the linearity of the spring is reduced. When the technically given opening and closing pressure difference Pqb is small, it is almost impossible to achieve it only by relying on the linearity of the spring itself, thus narrowing the problem of narrowing the scope of use of the back pressure valve. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes a high-pressure direct load-balanced back-pressure valve.

[0005] High pressure direct load balanced back pressure valve, including:

[0006] An upper valve body, wherein a high-pressure air chamber is provided inside the upper valve body;

[0007] A lower valve body is assembled in front of the upper valve body, a gas balance channel is provided inside the lower valve body and the upper valve body, and a sealing ring embedded in the gas balance channel is provided between the valve seat and the upper valve body;

[0008] A stepped valve core assembled in the high-pressure gas chamber, wherein two diameters of the valve core are d1 and d2 respectively;

[0009] The valve disc is assembled at the front end of the valve core;

[0010] A valve seat assembled between the rear end of the lower valve body and the front end of the upper valve body;

[0011] A spring sleeve is assembled on the rear end of the upper valve body, and a spring member connected to the rear end of the valve core is arranged inside the spring sleeve.

[0012] Preferably, one end of the gas balance channel is connected to the air inlet channel inside the lower valve body, and the other end of the gas balance channel is communicated with the high-pressure gas chamber.

[0013] Preferably, a spring lower support seat is assembled at the front end of the spring member, a limiting mechanism is arranged at the front end of the spring lower support seat, and a limiting steel ball is embedded between the inside of the limiting mechanism and the rear end of the valve core.

[0014] Preferably, the rear end of the spring member is equipped with a spring upper support seat, a steel ball is embedded in the spring upper support seat, and the rear end of the spring upper support seat is equipped with a spring upper cover, and an adjusting bolt extending into the spring upper support seat is embedded in the spring upper cover.

[0015] Preferably, a bolt cap sleeved on the adjusting bolt is arranged on the rear surface of the spring upper cover, and a protective cover sleeved on the spring upper cover is arranged on the left end.

[0016] Preferably, an arc-shaped groove fitting the steel sphere is formed at the front end of the adjusting bolt.

[0017] Preferably, a throat channel communicating with an air inlet channel inside the lower valve body is provided inside the valve seat, and the rear end of the throat channel has an inner chamfer of degrees.

[0018] Preferably, the front end chamfer of the valve core fits the inner chamfer of the throat channel.

[0019] Preferably, an output connector body is mounted at the bottom of the upper valve body, and an air outlet passage inside the output connector body is communicated with the high-pressure air chamber.

[0020] Preferably, the valve flap is fastened to the valve core by means of hexagon socket bolts, and the valve flap is in a convex shape.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention can reduce the three-dimensional size of the spring by calculating and selecting the appropriate spring force, and at the same time reduce the overall three-dimensional size of the valve, thereby solving the throat diameter limitation. By selecting a spring with a smaller pressure value, a back pressure valve or a pressure maintaining valve with a larger throat diameter can be designed, thereby improving the adjustment accuracy of the back pressure valve and expanding the application range of the back pressure valve.

[0023] (2) The PEEK conical surface embedded in the valve core of the present invention closely fits with the valve seat to form a narrow band face seal, thereby increasing the sealing cutoff effect, and the gas balance channel increases the buffering and protection effect of the valve disc and other components. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a direct load balancing back pressure valve of the present invention;

[0025] Figure 2 For the present invention Figure 1 Sectional view in the AA direction;

[0026] Figure 3It is a structural schematic diagram of the valve seat in the present invention;

[0027] In the figure: 1. Protective cover; 2. Adjusting bolt; 3. Bolt and cap; 4. Spring upper cover; 5. Steel ball; 6. Spring cover; 7. Spring part; 8. Spring lower support seat; 9. Limiting steel ball; 10. Valve core; 11. Upper valve body; 12. Output connector body; 13. Valve disc; 14. Valve seat; 15. Lower valve body; 16. Sealing ring; 17. Limiting mechanism; 18. Spring upper support seat; 19. Gas balance channel; 20. High-pressure gas chamber. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1

[0030] See also Figure 1 and Figure 2 , the present application provides a high pressure direct load balanced back pressure valve, comprising:

[0031] An upper valve body 11, wherein a high pressure air chamber 20 is provided inside the upper valve body 11;

[0032] A lower valve body 15 is assembled in front of the upper valve body 11, a gas balance channel 19 is opened inside the lower valve body 15 and the upper valve body 11, and a sealing ring 16 embedded in the gas balance channel 19 is arranged between the valve seat 14 and the upper valve body 11;

[0033] A T-shaped valve core 10 is assembled in the high-pressure gas chamber 20, and two diameters of the valve core 10 are d1 and d2 respectively;

[0034] A valve flap 13 mounted on the front end of the valve core 10;

[0035] by Figure 2 For example: When the input gas pressure is equal to the set pressure Pzd, a leftward thrust is generated on the valve disc 13 (diameter d0). At the same time, the input gas enters the high-pressure gas chamber 20 along the gas balance channel 19, generating a rightward thrust on the annular area formed by d2 and d1 on the valve core 10. At this time, the spring force Ft plus F2 equals F1, and the back pressure valve opens; according to the necessary condition for the valve to stabilize in the on state immediately after opening: Ath>Atk, the back pressure valve quickly reaches a stable on state after opening.

[0036] The air inlet passage of the lower valve body 15 and the air outlet passage of the output connector body 12 form an L-shaped exhaust passage to allow gas to flow.

[0037] When the input pressure Pin is reduced to Fth≤Ftk, the back pressure valve is closed, and the valve disc 13 abuts against the valve seat 14 to the right, cutting off the outlet passage in the output joint body 12 and the inlet passage of the lower valve body 15.

[0038] A sealing ring 16 is installed between the lower valve body 15 and the upper valve body 11 and is embedded in the gas balance channel 19. The lower valve body 15 and the upper valve body 11 are connected by four hexagon socket bolts.

[0039] A valve seat 14 is assembled between the rear end of the lower valve body 15 and the front end of the upper valve body 11;

[0040] A spring sleeve 6 is assembled at the rear end of the upper valve body 11 , and a spring member 7 connected to the rear end of the valve core 10 is arranged inside the spring sleeve 6 , so that the position of the valve core 10 can be adjusted.

[0041] In this embodiment, preferably, one end of the gas balance channel 19 is connected to the air inlet channel inside the lower valve body 15 , and the other end of the gas balance channel 19 is communicated with the high-pressure gas chamber 20 .

[0042] In this embodiment, preferably, a spring lower support seat 8 is assembled at the front end of the spring member 7, and a limiting mechanism 17 is provided at the front end of the spring lower support seat 8 to play a guiding and limiting role. A limiting steel ball 9 is embedded between the inside of the limiting mechanism 17 and the rear end of the valve core 10.

[0043] In this embodiment, preferably, the rear end of the spring member 7 is equipped with a spring upper support seat 18, a steel ball 5 is embedded inside the spring upper support seat 18, and the rear end of the spring upper support seat 18 is equipped with a spring upper cover 4, and the spring upper cover 4 is embedded with an adjusting bolt 2 extending into the spring upper support seat 18.

[0044] In this embodiment, preferably, a bolt cap 3 sleeved on the adjusting bolt 2 is provided on the rear surface of the spring upper cover 4, and a protective cover 1 sleeved on the spring upper cover 4 is provided on the left end to protect the spring member 7 and other components.

[0045] In this embodiment, preferably, an arc groove that fits the steel ball 5 is opened at the front end of the adjusting bolt 2, so as to facilitate assembly with the steel ball 5 and not affect the operation of the steel ball 5.

[0046] In this embodiment, preferably, a throat channel communicating with the air inlet channel inside the lower valve body 15 is opened inside the valve seat 14, and the inner chamfer at the rear end of the throat channel is 45 degrees, and the angle of the chamfer can be set according to actual production needs and is not limited to 45 degrees.

[0047] In the existing direct load back pressure valve, the spring member 7 is used to indirectly press the valve core 10 to adjust the opening set pressure, but the gas balance channel 19 and the stepped valve core 10 are not provided. The set pressure is set to Pzd. At this time, the required spring pressure is proportional to the throat diameter of the throat channel. The spring pressure is set to Ft, and the throat diameter is set to d0. The larger the throat diameter d0, the larger the required spring pressure Ft.

[0048] If the set pressure Pzd is high and the throat diameter d0 is large, the spring element 7 corresponding to the direct load will bear a large pressure. For example, if the set pressure is 25MPa and the throat diameter is 20mm, the valve opening area is calculated to be (Ak represents the symbol set when the conventional stepped valve core 10 is not provided, and Atk below represents the symbol set after the stepped valve core 10 is provided in the present application), at this time the spring pressure is Ft = 3.14cm*250kg / cm 2 =785kg, therefore, when the set pressure Pzd multiplied by the opening area Ak is greater than 1000kg, the spring load Ft is very large and the linearity of the spring is very low, so it is almost impossible to design a direct load back pressure valve (safety valve).

[0049] By using the stepped valve core 10, the diameters of the two steps of the valve core 10 can be set to d2 and d1, and d2>d1; in order to illustrate the principle of the present invention, according to Figure 2 As shown, list the following formula;

[0050] 1. Valve opening thrust area:

[0051]

[0052] 2. Thrust area after valve opening (set the thrust area after valve opening as Ath):

[0053]

[0054] 3. Valve opening thrust (set the valve opening thrust to Ftk):

[0055] Ftk=Pzdx Atk Formula (3);

[0056] 4. Thrust after valve opening (set the thrust after valve opening to Fth):

[0057] Fth=Pin×Ath Formula (4);

[0058] Pzd—set pressure, Pin—input pressure;

[0059] 5. Necessary conditions for the valve to stabilize in the on state immediately after opening: Ath>Atk;

[0060] The larger the value of Atk is, the faster the valve stabilizes after opening, and the larger the valve opening height H is.

[0061] 6. When the input pressure Pin decreases and Fth≤Ftk, the back pressure valve closes.

[0062] When the throat diameter d0 is determined, the appropriate values ​​of d2 and d1 can be selected according to formula (1), so that the valve opening thrust area Atk can be designed within a smaller range, so that the valve opening thrust Ftk is a smaller value, and a spring with a smaller spring force Ft can be selected.

[0063] For example, as mentioned above: throat diameter d0 = 20, Ak = 3.14 cm 2 , set pressure Pzd = 25MPa, spring force Ft = 785kg. Now using formula (1) and formula (2), after selecting appropriate d1 and d2 values, the value of Atk can be 1.4cm 2 So the spring pressure Ft is about 350kg. It can be seen that after adopting formula (1) and formula (2), the spring force is greatly reduced, the three-dimensional size of the spring is reduced, and the overall three-dimensional size of the valve is reduced.

[0064] From the design of back pressure valve, of course, it is better for the valve opening height H to be larger, so the thrust area Ath after the valve is opened needs to be larger, but Ath is directly related to the valve opening area Atk and the opening and closing pressure difference Pqb (the opening and closing pressure difference is the difference between the valve opening pressure and the return seat pressure, and the opening and closing pressure difference is set to Pqb, which is the prior art). The designer has made a lot of example calculations and obtained that: when the opening and closing pressure difference Pqb / set pressure Pzd≤10%, Ath must be a smaller value, and the opening height H is also small. At this time, the valve must be a micro-opening back pressure valve; when Pqb / Pzd≥15%~30%, Ath can be designed to be a larger value, so that the valve opening height H is also a larger value. At this time, the valve must be a full-opening pressure holding valve.

[0065] The designer uses the above four formulas. When the opening and closing pressure difference Pqb = 10%, the appropriate d1 and d2 values ​​are selected. According to formula (1) and formula (2), it is calculated that when the throat diameter d0 is between 20mm and 40mm, or even larger, the spring pressure Ft is always kept below 500kg. It is concluded that the essence of the present invention is: a back pressure valve or pressure holding valve with a larger throat diameter can be designed by selecting a spring with a smaller pressure value. The high-pressure direct load balanced back pressure valve (safety valve) is suitable for a pressure range of 5 to 70MPa, or even higher. The present invention is not only suitable for high-pressure gas, but also for high-pressure liquid.

[0066] High-pressure gas Pin is injected from the air inlet joint of the lower valve body 15. When the product of the value of the high-pressure gas Pin and the valve opening thrust area Atk is greater than the spring pressure Ft, the valve opens instantly. After the valve opens, since Ath>Atk, PinxAth>Ft, the back-pressure valve can be opened stably without frequency jumping and fluttering.

[0067] If the back pressure valve is used as a pressure maintaining valve, and the opening and closing pressure difference Pqb of the pressure maintaining valve is generally 20% to 30% of the set pressure, in this case, Ath can be designed to be a larger value, so that the pressure maintaining valve can quickly make the valve disc 13 reach the limit position at the moment of opening, and the limit device of the pressure maintaining valve determines the moving distance of the valve disc 13, which is the opening height of the valve.

[0068] Embodiment 2

[0069] Reference Figure 1 - Figure 3 , which is the second embodiment of the present invention, and this embodiment is different from the previous embodiment.

[0070] In this embodiment, preferably, the chamfer at the front end of the valve core 10 fits the chamfer inside the throat channel, and the two fit closely together to increase air tightness.

[0071] First, pre-tighten the adjusting bolt 2 to generate a spring pressure Ft through the spring element 7, and transmit it to the valve core 10 through the spring lower support seat 8 and the limiting steel ball 9, so that the PEEK cone surface embedded in the valve core 10 fits tightly with the valve seat 14 to form a narrow band surface seal.

[0072] In this embodiment, preferably, an output joint body 12 is assembled at the bottom of the upper valve body 11, and an outlet passage inside the output joint body 12 communicates with the cavity between the valve seat 14 and the valve disc 13 to facilitate gas discharge.

[0073] In this embodiment, preferably, the valve flap 13 is fastened to the valve core 10 by means of hexagon socket bolts, and the valve flap 13 is a convex structure.

[0074] Embodiment 3

[0075] This embodiment is obtained by combining the first embodiment and the second embodiment.

[0076] Assemble the various parts on the back pressure valve. When the input gas pressure is equal to the set pressure Pzd, a leftward thrust is generated on the valve disc 13 (diameter d0). At the same time, the input gas enters the high-pressure gas chamber 20 along the gas balance channel 19, generating a rightward thrust on the annular area formed by d2 and d1 on the valve core 10. At this time, the spring force Ft plus F2 equals F1, and the back pressure valve opens. According to the necessary condition for the valve to stabilize in the conduction state immediately after opening: Ath>Atk, the back pressure valve quickly reaches a stable conduction state after opening. When the input pressure Pin is reduced to Fth≤Ftk, the back pressure valve closes quickly and stably. The conical surface of the PEEK valve disc 13 embedded in the valve core 10 fits tightly with the valve seat 14 to form a narrow band face seal. The valve disc 13 presses against the valve seat 14 to the right, cutting off the outlet channel in the output connector body 12 and the inlet channel of the lower valve body 15.

[0077] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. High-pressure direct load-balanced back pressure valve, characterized in that: include: An upper valve body (11), wherein a high-pressure air chamber (20) is provided inside the upper valve body (11); a lower valve body (15) mounted in front of the upper valve body (11), wherein a gas balance channel (19) is provided inside the lower valve body (15) and the upper valve body (11), and a sealing ring (16) embedded in the gas balance channel (19) is provided between the valve seat (14) and the upper valve body (11); A stepped valve core (10) assembled in a high-pressure gas chamber (20), wherein two diameters of the valve core (10) are d1 and d2 respectively; A valve flap (13) mounted on the front end of the valve core (10); A valve seat (14) mounted between the rear end of the lower valve body (15) and the front end of the upper valve body (11); A spring sleeve (6) is mounted on the rear end of the upper valve body (11), wherein a spring member (7) connected to the rear end of the valve core (10) is arranged inside the spring sleeve (6).

2. The high-pressure direct load-balanced back-pressure valve according to claim 1, characterized in that: One end of the gas balance channel (19) is connected to the air inlet channel inside the lower valve body (15), and the other end of the gas balance channel (19) is in communication with the high-pressure gas chamber (20).

3. The high-pressure direct load-balanced back-pressure valve according to claim 1, characterized in that: The front end of the spring member (7) is equipped with a spring lower support seat (8), the front end of the spring lower support seat (8) is provided with a limit mechanism (17), and a limit steel ball (9) is embedded between the inside of the limit mechanism (17) and the rear end of the valve core (10).

4. The high-pressure direct load-balanced back-pressure valve according to claim 1, characterized in that: The rear end of the spring member (7) is equipped with a spring upper support seat (18), a steel ball (5) is embedded in the spring upper support seat (18), and the rear end of the spring upper support seat (18) is equipped with a spring upper cover (4), and an adjusting bolt (2) extending into the spring upper support seat (18) is embedded in the spring upper cover (4).

5. The high-pressure direct load-balanced back-pressure valve according to claim 4, characterized in that: The rear surface of the spring upper cover (4) is provided with a bolt cap (3) sleeved on the adjusting bolt (2), and the left end is provided with a protective cover (1) sleeved on the spring upper cover (4).

6. The high-pressure direct load-balanced back-pressure valve according to claim 5, characterized in that: The front end of the adjusting bolt (2) is provided with an arc-shaped groove which fits the steel ball (5).

7. The high-pressure direct load-balanced back-pressure valve according to claim 1, characterized in that: A throat channel communicating with the air inlet channel inside the lower valve body (15) is provided inside the valve seat (14), and the rear end of the throat channel has an inner chamfer of 45 degrees.

8. The high-pressure direct load-balanced back-pressure valve according to claim 7, characterized in that: The front end chamfer of the valve core (10) fits the inner chamfer of the throat channel.

9. The high-pressure direct load-balanced back-pressure valve according to claim 1, characterized in that: An output connector body (12) is mounted on the bottom of the upper valve body (11).

10. The high-pressure direct load-balanced back-pressure valve according to claim 1, characterized in that: The valve flap (13) is fastened and mounted on the valve core (10) by means of hexagon socket bolts, and the valve flap (13) is in the shape of a convex structure.

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