Differential pressure transmitter

Abstract

The present invention discloses a differential pressure transmitter, which includes a pressure inlet seat and a sealing cover. The sealing cover is arranged on the pressure inlet seat. A diaphragm pressure sensor is arranged inside the sealing cover. A lead outlet is arranged at the top of the sealing cover. The diaphragm pressure sensor is connected with a signal lead, and the signal lead passes outwards through the lead outlet. A lead connector is wrapped on the signal lead, and the lead connector plugs in the lead outlet and is sealed with it. A negative pressure oil injection hole is also arranged on the sealing cover, and an oil plug is arranged in the negative pressure oil injection hole. When using the differential pressure transmitter of the present invention, when the internal pressure of the diaphragm pressure sensor is too high and it has a tendency to separate outwards, and the liquid pressure transmission medium in the installation cavity is not easily compressed, it can, to a certain extent, prevent the tendency of the diaphragm pressure sensor to separate, and adopts a suspension installation method, avoiding the abutment of the isolation diaphragm and / or the welding ring against the assembly part, and the isolation diaphragm will not be deformed during the installation process, solving the influence of clamping stress on the measurement accuracy.

Description

Technical Field

[0001] The present invention relates to a pressure measuring device, and particularly to a differential pressure transmitter. Background Art

[0002] The core detection component of a capacitive differential pressure transmitter is a diaphragm-type capacitive differential pressure transmitter (diaphragm-type pressure sensor), which converts two externally applied different pressure signals into respective corresponding capacitance changes, and the subsequent detection circuit converts the capacitance change into an electrical signal, and by processing and detecting this electrical signal, the differential pressure value of the externally applied pressure can be obtained.

[0003] The diaphragm-type pressure sensor includes two disc-shaped diaphragm seats, the edges of the two diaphragm seats are welded, a diaphragm deformation cavity is provided between the two diaphragm seats, and a measuring diaphragm is provided between the two diaphragm seats. The two diaphragm seats are respectively penetrated by pressure transmission channels, which introduce the externally measured pressure to both sides of the measuring diaphragm, and the magnitude of the deformation of the measuring diaphragm reflects the magnitude of the differential pressure.

[0004] The traditional installation method of the diaphragm-type pressure sensor is to provide an isolation diaphragm on the outer wall of the diaphragm seat, and the isolation diaphragm closes the outer port of the pressure transmission channel. In order to facilitate the installation and stability of the isolation diaphragm, a welding ring is generally provided on the outside of the isolation diaphragm, and then silicone oil is filled in the pressure transmission channel and the diaphragm deformation cavity to keep the measuring diaphragm in a fixed initial position, and a stable pressure system is formed inside the diaphragm-type pressure sensor; the above isolation diaphragm is fixed on the diaphragm-type pressure sensor and then installed together in the later stage; this leads to the following two main problems:

[0005] 1. During the later assembly process, the isolation diaphragm and / or the welding ring abuts against the assembly part. Affected by the clamping stress, the isolation diaphragm is prone to deformation, thereby promoting the flow of the internal silicone oil, causing the initial positions of the measuring diaphragms of each transmitter to change in different situations, affecting the measurement accuracy;

[0006] 2. When measuring high-pressure fluids, the pressure in the deformation cavity increases significantly, and there is a tendency to push the welds of the two diaphragm seats to crack. This situation becomes more serious with the increase of time and pressure, which is not conducive to extending the service life of the diaphragm-type pressure sensor.

[0007] Therefore, it is necessary to comprehensively consider and solve the above problems and design a set of suitable technical solutions. Summary of the Invention

[0008] In view of this, the present invention provides a differential pressure transmitter.

[0009] The technical solution is as follows:

[0010] A differential pressure transmitter includes a pressure guiding seat and a sealing cover. The sealing cover covers the pressure guiding seat. A diaphragm pressure sensor is provided inside the sealing cover. A lead outlet is provided at the top of the sealing cover. The diaphragm pressure sensor is connected with a signal lead, and the signal lead passes outwards through the lead outlet. A lead connector is wrapped around the signal lead, and the lead connector plugs into the lead outlet and is sealed with it.

[0011] A negative pressure oil injection hole is further provided on the sealing cover, and an oil plug is provided in the negative pressure oil injection hole.

[0012] The advantage of adopting the above scheme is that by using the suspended installation method, it is avoided that the isolation diaphragm and / or the welding ring abuts against the assembly part, and the isolation diaphragm will not be deformed during the installation process.

[0013] The negative pressure oil injection hole includes a threaded hole section, a tapered hole section and a small hole section that are connected in sequence. The large end of the tapered hole section is connected to the threaded hole section, and the small end of the tapered hole section is connected to the small hole section. A sealing ball is provided in the tapered hole section. The oil plug is screwed into the threaded hole section, and the oil plug presses the sealing ball against the hole wall of the tapered hole section.

[0014] It further includes two pressure taking seats arranged oppositely, and the pressure guiding seat is provided between the two pressure taking seats;

[0015] Two pressure guiding channels penetrate through the pressure guiding seat. One end of the pressure guiding channel is an inlet, and the other end of the pressure guiding channel is an outlet. The inlet ends of the two pressure guiding channels respectively face the two pressure taking seats;

[0016] Pressure taking channels respectively penetrate through the two pressure taking seats. The inner end of the pressure taking channel is butted against the inlet end of the corresponding pressure guiding channel, and the outer end of the pressure taking channel passes out of the corresponding pressure taking seat;

[0017] Two pressure guiding pipes are led outwards from the diaphragm pressure sensor. The inner ends of the two pressure guiding pipes are connected to the inside of the diaphragm pressure sensor, and the outer ends of the two pressure guiding pipes are respectively connected to the outlet ends of the two pressure guiding channels.

[0018] Pressure guiding pipe sockets are respectively arranged around the outlet ends of the pressure guiding channels on the pressure guiding seat. The outer ends of the pressure guiding pipes are inserted into the corresponding pressure guiding pipe sockets, and the outer wall of the pressure guiding pipe is welded and sealed with the pressure guiding pipe socket.

[0019] The outlet ends of the two pressure guiding channels penetrate out from the same side of the pressure guiding seat. A placement counterbore is further provided on the pressure guiding seat between the outlet ends of the two pressure guiding channels. The lower part of the diaphragm pressure sensor floats in the placement counterbore.

[0020] On the back of the pressure guiding seat, there are two parallel mounting sides. The inlet ends of the two pressure guiding channels respectively penetrate out from the two mounting sides. An annular diaphragm mounting seat is provided around the inlet end of the pressure guiding channel on the mounting side. The diaphragm mounting seat is an annular welding boss. The interior of the diaphragm mounting seat encloses a pressure guiding area. The port of the inlet end of the pressure guiding channel is respectively located in the corresponding pressure guiding area. The two pressure taking seats correspond to the two mounting sides one by one. An assembly plane is provided on the pressure taking seat corresponding to its mounting side. The assembly plane is attached to and sealed with the corresponding mounting side. A pressure taking area is provided on the assembly plane corresponding to the pressure guiding area. The inner end of the pressure taking channel is connected to the pressure taking area. The pressure taking area is docked with the corresponding pressure guiding area.

[0021] The pressure guiding seat includes a mounting base and a sensor mounting seat. The mounting base is in a cubic shape. Two opposite sides of the mounting base form the two mounting sides. The mounting sides are vertically arranged. The sensor mounting seat is fixed on the upper end surface of the mounting base. The outlet ends of the two pressure guiding channels respectively penetrate out from the upper end surface of the sensor mounting seat;

[0022] The sensor mounting seat includes a horizontally placed docking plate. The lower surface of the docking plate is fixed to the upper end surface of the mounting base. A docking seat is fixed on the upper surface of the docking plate. The edge of the docking plate extends outwards and exceeds the docking seat. The pressure guiding pipe socket is located on the upper surface of the docking seat. The outer wall of the docking seat is provided with a socket thread. A sealing cover is sleeved on the docking seat. The sealing cover is threadedly sleeved on the docking seat. The sealing cover abuts against the docking plate and is welded and sealed;

[0023] The outlet ends of the pressure guiding channels penetrate out from the upper end surface of the docking seat. The outlet ends of the two pressure guiding channels are at the same horizontal height. The projection of the connection line of the outlet ends of the two pressure guiding channels on the horizontal plane forms an angle α with the mounting side, and α = 45°.

[0024] A pressure balance channel also penetrates through the pressure guiding seat. The pressure balance channel is vertically arranged. The upper end of the pressure balance channel penetrates upwards through the docking seat. The lower end of the pressure balance channel penetrates downwards through the mounting base. The lower end of the pressure balance channel is connected to the same pressure source as the inlet end of the pressure guiding channel.

[0025] Isolation diaphragms are respectively provided at the inlet ends of the two pressure guiding channels and at the lower end of the pressure balance channel. The edge of the isolation diaphragm is sealed and fixed to the corresponding part of the pressure guiding seat;

[0026] The isolation diaphragm for blocking the inlet end of the pressure guiding channel is covered on the pressure guiding area. Its edge is welded and sealed with the annular welding boss;

[0027] The pressure guiding channel, the pressure guiding pipe and the inside of the diaphragm pressure sensor are internally connected. The pressure balance channel and the inside of the sealing cover are internally connected. The inside and the outside of the diaphragm pressure sensor are isolated from each other.

[0028] The pressure guiding channel, the pressure guiding pipe, the inside of the diaphragm pressure sensor, the pressure balance channel and the inside of the sealing cover are filled with a pressure transmission medium.

[0029] A turning counterbore is provided around the lower end port of the pressure balance channel on the bottom surface of the mounting base.

[0030] An isolation diaphragm for blocking the lower end port of the pressure balance channel is provided at the bottom of the turning counterbore, and its edge is welded and sealed to the bottom of the turning counterbore.

[0031] A plug is fixedly provided at the outer end of the turning counterbore. A balance pressure tapping area is formed between the plug and the corresponding isolation diaphragm. A balance pressure tapping hole penetrates through the hole wall of the turning counterbore. The inner end of the balance pressure tapping hole is connected to the balance pressure tapping area. The outer end of the balance pressure tapping hole penetrates out of the mounting base. The outer end of the balance pressure tapping hole and the inlet end of any one of the pressure guiding channels are located on the same side of the mounting base.

[0032] A pressure tapping branch hole is further provided on the pressure tapping seat. One end of the pressure tapping branch hole is connected to the pressure tapping area. The other end of the balance pressure tapping hole is connected to the pressure tapping branch hole on any one of the pressure tapping seats.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: when the pressure inside the diaphragm pressure sensor is too high, it has a tendency to separate outward. However, the liquid pressure transmission medium in the installation cavity is not easily compressed, which can, to a certain extent, prevent the tendency of the diaphragm pressure sensor to separate, thereby preventing it from cracking too quickly. And a suspension installation method is adopted to avoid the isolation diaphragm and / or the welding ring from abutting against the assembly part, and the isolation diaphragm will not be deformed during the installation process, solving the influence of clamping stress on the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of the present invention;

[0035] Figure 2 is Figure 1 an enlarged view of part D of

[0036] Figure 3 is a three-dimensional structural diagram of the present invention;

[0037] Figure 4 is a schematic connection diagram of the diaphragm pressure sensor 25 and the mounting base 23;

[0038] Figure 5 is Figure 4 an enlarged view of part C;

[0039] Figure 6 is a schematic cross-sectional view of the connection relationship among the diaphragm pressure sensor 25, the mounting base 23 and the sealing cover 3;

[0040] Figure 7 is Figure 6 an enlarged view of part A;

[0041] Figure 8 is Figure 6 an enlarged view of part B;

[0042] Figure 9 is a schematic structural view of the mounting base 23;

[0043] Figure 10 is Figure 9 a top view;

[0044] Figure 11 is Figure 10 a sectional view taken along Z-Z`; Detailed implementation mode

[0045] The present invention will be further described below in conjunction with embodiments and the drawings.

[0046] As Figures 1 to 11 shown, a differential pressure transmitter includes a pressure guiding seat 2 and a sealing cover 3. The sealing cover 3 covers the pressure guiding seat 2. A diaphragm pressure sensor 25 is arranged in the sealing cover 3. A lead outlet is arranged at the top of the sealing cover 3. The diaphragm pressure sensor 25 is connected with a signal lead, and the signal lead penetrates out of the lead outlet. A lead connector 31 is wrapped on the signal lead, and the lead connector 31 plugs in the lead outlet and seals it;

[0047] A negative pressure oil injection hole 3a is further arranged on the sealing cover 3, and an oil plug 32 is arranged in the negative pressure oil injection hole 3a.

[0048] Wherein:

[0049] The negative pressure oil injection hole 3a includes a threaded hole section, a tapered hole section and a small hole section which are connected in sequence. The large end of the tapered hole section is connected with the threaded hole section, and the small end of the tapered hole section is connected with the small hole section. A sealing ball 33 is arranged in the tapered hole section. The oil plug 32 is screwed in the threaded hole section, and the oil plug 32 presses the sealing ball 33 against the hole wall of the tapered hole section.

[0050] It further includes two pressure taking seats 1 which are arranged opposite to each other, and the pressure guiding seat 2 is arranged between the two pressure taking seats 1;

[0051] There are two pressure guiding channels 2a penetrating through the pressure guiding seat 2. One end of each pressure guiding channel 2a is an inlet, and the other end is an outlet. The inlet ends of the two pressure guiding channels 2a respectively face the two pressure tapping seats 1;

[0052] Pressure tapping channels 1a penetrate through the two pressure tapping seats 1 respectively. The inner end of each pressure tapping channel 1a is butted against the inlet end of the corresponding pressure guiding channel 2a, and the outer end of the pressure tapping channel 1a penetrates out of the corresponding pressure tapping seat 1;

[0053] The diaphragm pressure sensor 25 leads out two pressure guiding pipes 251. The inner ends of the two pressure guiding pipes 251 are connected to the inside of the diaphragm pressure sensor 25, and the outer ends of the two pressure guiding pipes 251 are respectively connected to the outlet ends of the two pressure guiding channels 2a.

[0054] In a specific implementation, the free ends of the two pressure guiding pipes 251 are respectively connected to a high-pressure source and a low-pressure source.

[0055] Pressure guiding pipe sockets 22 are respectively arranged around the outlet ends of the pressure guiding channels 2a on the pressure guiding seat 2. The outer ends of the pressure guiding pipes 251 are inserted into the corresponding pressure guiding pipe sockets 22, and the outer walls of the pressure guiding pipes 251 are welded and sealed with the pressure guiding pipe sockets 22.

[0056] The outlet ends of the two pressure guiding channels 2a penetrate out from the same side surface of the pressure guiding seat 2. A placement sink is also arranged on the pressure guiding seat 2 between the outlet ends of the two pressure guiding channels 2a. The lower part of the diaphragm pressure sensor 25 is suspended in the placement sink.

[0057] Two mutually parallel mounting side surfaces are provided on the pressure guiding seat 2 in a back-to-back manner. The inlet ends of the two pressure guiding channels 2a respectively penetrate out from the two mounting side surfaces. Annular diaphragm mounting seats 21 are arranged around the inlet ends of the pressure guiding channels 2a on the mounting side surfaces. The diaphragm mounting seats 21 are annular welding bosses. The inside of the diaphragm mounting seats 21 encloses a pressure guiding area. The port ends of the inlet ends of the pressure guiding channels 2a are respectively located in the corresponding pressure guiding areas. The two pressure tapping seats 1 correspond to the two mounting side surfaces one by one. An assembly plane is provided on the pressure tapping seat 1 corresponding to its mounting side surface. The assembly plane is attached to and sealed with the corresponding mounting side surface. A pressure tapping area 1b is provided on the assembly plane corresponding to the pressure guiding area. The inner end of the pressure tapping channel 1a is connected to the pressure tapping area 1b, and the pressure tapping area 1b is butted against the corresponding pressure guiding area.

[0058] The pressure guiding seat 2 includes a mounting base 23 and a sensor mounting seat 24. The mounting base 23 is in a cubic shape. Two opposite side surfaces of the mounting base 23 form two mounting side surfaces, and the mounting side surfaces are arranged vertically. The sensor mounting seat 24 is fixed to the upper end surface of the mounting base 23, and the outlet ends of the two pressure guiding channels 2a respectively penetrate out from the upper end surface of the sensor mounting seat 24;

[0059] The sensor mounting seat 24 includes a docking plate 241 placed horizontally. The lower surface of the docking plate 241 is fixed to the upper end surface of the mounting base 23, and a docking seat 242 is fixed on the upper surface of the docking plate 241. The edge of the docking plate 241 extends outward and exceeds the docking seat 242. The pressure guiding pipe socket 22 is located on the upper surface of the docking seat 242. The outer wall of the docking seat 242 is provided with a socket thread. A sealing cover 3 is sleeved on the docking seat 242, and the sealing cover 3 is threadedly sleeved on the docking seat 242. The sealing cover 3 abuts against the docking plate 241 and is welded and sealed;

[0060] The outlet ends of the pressure guiding channels 2a penetrate out from the upper end surface of the docking seat 242. The outlet ends of the two pressure guiding channels 2a are at the same horizontal height. The projection of the connection line of the outlet ends of the two pressure guiding channels 2a on the horizontal plane forms an angle α with the mounting side surface, and α = 45°.

[0061] To further improve the pressure balance effect, a pressure balance channel 2b also penetrates through the pressure guiding seat 2. The pressure balance channel 2b is arranged vertically. The upper end of the pressure balance channel 2b penetrates upward through the docking seat 242, and the lower end of the pressure balance channel 2b penetrates downward through the mounting base 23. The lower end of the pressure balance channel 2b is connected to the inlet end of the pressure guiding channel 2a to the same pressure source.

[0062] Isolation diaphragms 26 are respectively arranged at the inlet ends of the two pressure guiding channels 2a and at the lower end of the pressure balance channel 2b. The edge of the isolation diaphragm 26 is sealed and fixed to the corresponding part of the pressure guiding seat 2;

[0063] The isolation diaphragm 26 for blocking the inlet end of the pressure guiding channel 2a is covered on the pressure guiding area, and its edge is welded and sealed to the annular welding boss;

[0064] The pressure guiding channels 2a, the pressure guiding pipes 251 and the diaphragm type pressure sensor 25 are internally connected. The pressure balance channel 2b and the inside of the sealing cover 3 are internally connected. The inside and outside of the diaphragm type pressure sensor 25 are isolated from each other;

[0065] The pressure transmission medium fills the inside of the pressure guiding channel 2a, inside the pressure guiding pipe 251, inside the diaphragm pressure sensor 25, inside the pressure balance channel 2b, and inside the sealing cover 3.

[0066] A steering counterbore 2c is provided around the lower end port of the pressure balance channel 2b on the bottom surface of the mounting base 23.

[0067] An isolation diaphragm 26 for blocking the lower end port of the pressure balance channel 2b is provided at the bottom of the steering counterbore 2c, and its edge is welded and sealed to the bottom of the steering counterbore 2c.

[0068] A plug 27 is also fixedly provided at the outer end of the steering counterbore 2c. A balanced pressure tapping area is formed between the plug 27 and the corresponding isolation diaphragm 26. A balanced pressure tapping hole 2d penetrates through the hole wall of the steering counterbore 2c. The inner end of the balanced pressure tapping hole 2d is connected to the balanced pressure tapping area, and the outer end of the balanced pressure tapping hole 2d penetrates out of the mounting base 23. The outer end of the balanced pressure tapping hole 2d and the inlet end of any one of the pressure guiding channels 2a are located on the same side of the mounting base 23.

[0069] A pressure tapping branch hole 1c is further provided on the pressure tapping seat 1. One end of the pressure tapping branch hole 1c is connected to the pressure tapping area 1b, and the other end of the balanced pressure tapping hole 2d is connected to the pressure tapping branch hole 1c on any one of the pressure tapping seats 1. Preferably, the outer end of the pressure balance channel 2b is connected to the high-pressure source.

[0070] Two first negative-pressure oil injection holes are further provided on the pressure guiding seat 2, and two first negative-pressure oil injection holes penetrate through the sealing cover 3. The two first negative-pressure oil injection holes respectively correspond to two pressure guiding areas. One end of the first negative-pressure oil injection hole penetrates out of the pressure guiding seat 2, and the other end of the first negative-pressure oil injection hole is connected to the corresponding pressure guiding area. A second negative-pressure oil injection hole 3a also penetrates through the sealing cover 3, and the second negative-pressure oil injection hole 3a connects the inside and outside of the sealing cover 3.

[0071] In the above structure, except for the sealing cover 3, other components are first assembled into a whole, evacuated through the two first negative pressure oil injection holes, and the vacuum degree is kept consistent. Then, by switching the valves of the gas path and the oil path, silicone oil is injected into the two first negative pressure oil injection holes. The silicone oil will fill the pressure guiding area, the pressure guiding channel 2a, the pressure guiding pipe 251 and the inside of the diaphragm pressure sensor 25. Then, a first oil plug is set in the first negative pressure oil injection hole for plugging. After that, check whether there is oil leakage. If no oil leakage is found, then assemble the sealing cover 3 and complete the sealing, evacuate through the second negative pressure oil injection hole 3a, and then, by switching the valves of the gas path and the oil path, inject silicone oil into the second negative pressure oil injection hole 3a. The silicone oil will fill the inside of the sealing cover 3 (installation cavity) and the pressure balance channel 2b. Finally, a second oil plug 32 is set in the negative pressure oil injection hole 3a for plugging.

[0072] Finally, it should be noted that the above description is only the preferred embodiment of the present invention. Under the inspiration of the present invention, those of ordinary skill in the art can make various similar representations without violating the purpose and claims of the present invention. Such transformations all fall within the protection scope of the present invention.

Claims

1. A differential pressure transmitter, characterized in that: It includes a pressure guiding seat (2) and a sealing cover (3). The sealing cover (3) covers the pressure guiding seat (2). A diaphragm pressure sensor (25) is arranged in the sealing cover (3). The diaphragm pressure sensor (25) adopts a suspended installation method. A lead outlet is arranged at the top of the sealing cover (3). The diaphragm pressure sensor (25) is connected with a signal lead, and this signal lead passes outwards through the lead outlet. A lead connector (31) is wrapped on the signal lead, and this lead connector (31) plugs in the lead outlet and seals it with the lead outlet. A negative pressure oil injection hole (3a) is also arranged on the sealing cover (3), and an oil plug (32) is arranged in this negative pressure oil injection hole (3a). It also includes two pressure taking seats (1) arranged opposite to each other, and the pressure guiding seat (2) is arranged between the two pressure taking seats (1). Two pressure guiding channels (2a) penetrate through the pressure guiding seat (2). One end of the pressure guiding channel (2a) is an inlet, and the other end of the pressure guiding channel (2a) is an outlet. The inlet ends of the two pressure guiding channels (2a) respectively face the two pressure taking seats (1). Pressure taking channels (1a) penetrate through the two pressure taking seats (1) respectively. The inner end of the pressure taking channel (1a) is butted against the inlet end of the corresponding pressure guiding channel (2a), and the outer end of the pressure taking channel (1a) passes out of the corresponding pressure taking seat (1). Two pressure guiding pipes (251) are led outwards from the diaphragm pressure sensor (25). The inner ends of the two pressure guiding pipes (251) are connected to the inside of the diaphragm pressure sensor (25), and the outer ends of the two pressure guiding pipes (251) are respectively connected to the outlet ends of the two pressure guiding channels (2a). The pressure guiding seat (2) includes an installation base (23) and a sensor installation seat (24). The sensor installation seat (24) includes a horizontally placed docking plate (241). The sealing cover (3) abuts against the docking plate (241) and is welded and sealed. A pressure balance channel (2b) also penetrates through the pressure guiding seat (2). The pressure balance channel (2b) is vertically arranged. The pressure guiding channels (2a), the pressure guiding pipes (251), the inside of the diaphragm pressure sensor (25), the pressure balance channel (2b), and the inside of the sealing cover (3) are filled with a pressure transmission medium. The negative pressure oil injection hole (3a) includes a threaded hole section, a tapered hole section, and a small hole section that are connected in sequence. The large end of the tapered hole section is connected to the threaded hole section, and the small end of the tapered hole section is connected to the small hole section.

2. The differential pressure transmitter according to claim 1, wherein: A sealing ball (33) is arranged in the tapered hole section. The oil plug (32) is screwed in the threaded hole section, and the oil plug (32) presses the sealing ball (33) against the hole wall of the tapered hole section.

3. The differential pressure transmitter according to claim 1, wherein: Pressure guiding pipe sockets (22) are respectively arranged around the outlet ends of the pressure guiding channels (2a) on the pressure guiding seat (2). The outer ends of the pressure guiding pipes (251) are inserted into the corresponding pressure guiding pipe sockets (22), and the outer wall of the pressure guiding pipe (251) is welded and sealed with the pressure guiding pipe socket (22).

4. The differential pressure transmitter according to claim 3, wherein: The outlet ends of the two pressure guiding channels (2a) penetrate out from the same side surface of the pressure guiding seat (2). A placing counterbore is further provided on the pressure guiding seat (2) between the outlet ends of the two pressure guiding channels (2a), and the lower part of the diaphragm pressure sensor (25) is suspended in the placing counterbore.

5. The differential pressure transmitter according to claim 4, wherein: On the pressure guiding seat (2), there are two parallel mounting side surfaces arranged back to back. The inlet ends of the two pressure guiding channels (2a) respectively penetrate out from the two mounting side surfaces. An annular diaphragm mounting seat (21) is provided around the inlet ends of the pressure guiding channels (2a) on the mounting side surfaces. The diaphragm mounting seat (21) is an annular welding boss. The interior of the diaphragm mounting seat (21) encloses a pressure guiding area. The port of the inlet end of the pressure guiding channel (2a) is respectively located in the corresponding pressure guiding area. The two pressure tapping seats (1) correspond to the two mounting side surfaces one by one. The pressure tapping seat (1) is provided with an assembly plane corresponding to its mounting side surface. The assembly plane is attached to and sealed with the corresponding mounting side surface. A pressure tapping area (1b) is provided on the assembly plane corresponding to the pressure guiding area. The inner end of the pressure tapping channel (1a) is communicated with the pressure tapping area (1b). The pressure tapping area (1b) is docked with the corresponding pressure guiding area.

6. The differential pressure transmitter according to claim 5, wherein: The mounting base (23) is in a cubic shape. Two opposite side surfaces of the mounting base (23) form the two mounting side surfaces. The mounting side surfaces are arranged vertically. The sensor mounting seat (24) is fixed on the upper end surface of the mounting base (23). The outlet ends of the two pressure guiding channels (2a) respectively penetrate out from the upper end surface of the sensor mounting seat (24); The lower surface of the docking disc (241) is fixed to the upper end surface of the mounting base (23). A docking seat (242) is fixed on the upper surface of the docking disc (241). The edge of the docking disc (241) extends outwards and exceeds the docking seat (242). The pressure guiding pipe socket (22) is located on the upper surface of the docking seat (242). The outer wall of the docking seat (242) is provided with a socket thread. A sealing cover (3) is sleeved on the docking seat (242). The sealing cover (3) is threadedly sleeved on the docking seat (242); The outlet ends of the pressure guiding channels (2a) penetrate out from the upper end surface of the docking seat (242). The outlet ends of the two pressure guiding channels (2a) are at the same horizontal height. The projection of the connecting line of the outlet ends of the two pressure guiding channels (2a) on the horizontal plane forms an angle α with the mounting side surface, and α = 45°.

7. The differential pressure transmitter according to claim 6, wherein: The upper end of the pressure balance channel (2b) penetrates upwards through the docking seat (242). The lower end of the pressure balance channel (2b) penetrates downwards through the mounting base (23). The lower end of the pressure balance channel (2b) is connected to the same pressure source as the inlet end of the pressure guiding channel (2a).

8. The differential pressure transmitter according to claim 7, wherein: Isolation diaphragms (26) are respectively provided at the inlet ends of the two pressure guiding channels (2a) and at the lower end of the pressure balance channel (2b). The edge of the isolation diaphragm (26) is sealed and fixed to the corresponding part of the pressure guiding seat (2); The isolation diaphragm (26) for blocking the inlet end of the pressure guiding channel (2a) is covered on the pressure guiding area, and its edge is welded and sealed with the annular welding boss; The pressure guiding channel (2a), the pressure guiding pipe (251) and the diaphragm pressure sensor (25) are internally connected, the pressure balance channel (2b) and the inside of the sealing cover (3) are connected, and the inside and outside of the diaphragm pressure sensor (25) are isolated from each other.

9. The differential pressure transmitter according to claim 8, wherein: A steering counterbore (2c) is provided around the lower end port of the pressure balance channel (2b) on the bottom surface of the mounting base (23); The isolation diaphragm (26) for blocking the lower end port of the pressure balance channel (2b) is provided at the bottom of the steering counterbore (2c), and its edge is welded and sealed with the bottom of the steering counterbore (2c); A plug (27) is fixedly provided at the outer end of the steering counterbore (2c), a balanced pressure tapping area is formed between the plug (27) and the corresponding isolation diaphragm (26), and a balanced pressure tapping hole (2d) penetrates through the hole wall of the steering counterbore (2c). The inner end of the balanced pressure tapping hole (2d) is connected to the balanced pressure tapping area, the outer end of the balanced pressure tapping hole (2d) penetrates out of the mounting base (23), and the outer end of the balanced pressure tapping hole (2d) and the inlet end of any one of the pressure guiding channels (2a) are located on the same side of the mounting base (23); A pressure tapping branch hole (1c) is further provided on the pressure tapping seat (1), one end of the pressure tapping branch hole (1c) is connected to the pressure tapping area (1b), and the other end of the balanced pressure tapping hole (2d) is connected to the pressure tapping branch hole (1c) on any one of the pressure tapping seats (1).

Images