JPH11132888A - Differential pressure-measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve corrosion resistance and durability of a differential pressure-measuring apparatus by providing a main body block, a doughnut- shaped flange part, a cylindrical protecting cover body of tantalum covering cylindrical two buffer material parts, and setting a seal diaphragm unit with a diaphragm projection type diaphragm main body. SOLUTION: A seal diaphragm 22 is formed of tantalum having a tantalum seal ring 23 set at one face of a projecting part of a projection type diaphragm unit main body 21 and receiving a pressure of a measurement fluid. The main body 21 is constituted of a block 211, a flange part 212, a first and a second buffer material parts 213, 214 and a protecting cover body 215 in one body. The first and second buffer material parts 213, 214 buffer a difference of thermal expansion coefficients between the main body block 211 and cover body 215 and between the flange part 212 and cover body 215 respectively. Since a high- quality tantalum face without a weld part or a pin hole at a liquid touch part is obtained, corrosion resistance is good and durability to damage from outside is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a liquid contact portion of a flange-mounted or diaphragm seal type differential pressure measuring device, and more particularly to a differential pressure measuring device having corrosion resistance and proof strength.

[0002]

2. Description of the Related Art FIG. 5 is an explanatory view showing the structure of a conventional example conventionally used as a "differential pressure gauge with a diaphragm-projecting diaphragm seal", and shows an example in which it is mounted on a tank. FIG. 6 is a detailed explanatory view of a main part of FIG.

In FIG. 1, a differential pressure measuring device main body 1 is a main portion of the differential pressure measuring device, comprising a main body capsule 2 and a cover 3 covering the main body capsule 2. Body capsule 2
In this case, a capacitance detection type is used.

The high-pressure capillary tube 4 is a tube having one end connected to the high-pressure cover 3. In this case, a flexible capillary tube is used.

High pressure side diaphragm seal unit 5
Is a diaphragm seal unit connected to the other end of the capillary tube 4 on the high pressure side. The high pressure side diaphragm seal unit 5 has a flange 51, a main body block 52, and a seal diaphragm 53.

High pressure side diaphragm seal unit 5
As shown in FIG. 6, a flange 5 is provided through a gasket D to a flange C provided in a mounting hole B of a tank body A.
One part is attached. The flange 51 is sandwiched between the flange C and the flange E, and is fixed by the bolt F and the nut G.

The sealed liquid 6 is a sealed liquid sealed in the diaphragm seal unit 5, the high-pressure side capillary tube 4, and the high-pressure side cover 3. In this case, silicone oil is used.

The low pressure side capillary tube 7 is a tube having one end connected to the low pressure side cover 3.
In this case, a flexible capillary tube is used. The low pressure side diaphragm seal unit 8 is a diaphragm seal unit connected to the other end of the low pressure side capillary tube 7.

The diaphragm seal unit 8 on the low pressure side
Has a flange 81, a main body block 82, and a seal diaphragm 83.

[0010] Low pressure side diaphragm seal unit 5
As shown in FIG. 6, a flange 8 is provided on a flange C provided in a mounting hole B of a tank body A via a gasket D.
1 is attached. The flange 81 is sandwiched between the flange C and the flange E, and is fixed by the bolt F and the nut G.

The sealed liquid 9 is a sealed liquid sealed in the diaphragm seal unit 8, the capillary tube 9 on the low pressure side, and the cover 3 on the low pressure side. In this case, silicone oil is used. The converter section 11 is a converter attached to the main body capsule 2.

[0012] In the above configuration, a part of the diaphragm seal units 5 and 8 that is in contact with the measurement fluid needs to be protected with a tantalum material for the corrosive measurement fluid.

FIG. 7 is an explanatory view of the configuration of a main part of a conventional example in which a liquid contact portion is protected by a tantalum material using welding. In the figure, a tantalum seal diaphragm 13 is welded to the bottom surfaces of the main body blocks 52 and 82 via a tantalum seal ring 12.

The coating 14 has a thickness of 0.1 mm in this case.
Is covered so that the outer surfaces of the main body blocks 52 and 82 and the liquid contact surfaces of the flanges 51 and 81 are not exposed, and the entire surface is covered by electron beam welding or the like.

However, in such a device, (1) the outer surfaces of the main body blocks 52 and 82 and the flange 5
A tantalum sheet is welded to the liquid contact surfaces of 1,81.

Therefore, in the welded portion, the coating 13 of the tantalum material and the base material of the main body blocks 52, 82 or the flanges 51, 81 are mixed by welding, and the main body blocks 52, 82 or the flanges 51, 81 are mixed. May be exposed on the surface. For this reason, there is a disadvantage that corrosion of the base material easily occurs.

(2) Main body blocks 52, 8 having large volumes
There is a disadvantage in that welding of the tread 2 and the flanges 51 and 81 to a tantalum material which is inherently difficult to weld, in particular, a thin sheet having a small capacity requires a long time.

FIG. 8 is an explanatory view of the configuration of a main part of a conventional example in which a liquid contact portion is protected by a tantalum material by using thermal spraying. In the figure, a tantalum seal diaphragm 13 is welded to the bottom surfaces of the main body blocks 52 and 82 via a tantalum seal ring 12.

In this case, the sprayed film 15 has a thickness of 0.5 m.
The sprayed film of m is covered with a thermal spray coating so that the outer surfaces of the main body blocks 52 and 82 and the liquid contact surfaces of the flanges 51 and 81 are not exposed.

[0020]

However, in such an apparatus, (1) a pinhole is easily generated in the sprayed film 15, and in order to fill the pinhole, the sprayed film 15 of tantalum is
Further, it has a disadvantage that it is often necessary to spray ceramics.

(2) Since the thermal spraying temperature is high, there is a disadvantage that a cooling device is required to prevent heat from being applied to the seal diaphragm 13.

The present invention solves this problem. An object of the present invention is to provide a differential pressure measuring device having corrosion resistance and proof stress.

[0023]

In order to achieve the above object, the present invention provides: (1) a projecting diaphragm unit main body having a convex shape;
A differential diaphragm measuring device including a sealing diaphragm projecting type diaphragm unit including a sealing diaphragm made of a tantalum material provided on one surface of the projecting portion via a sealing ring made of a tantalum material and receiving pressure of a measurement fluid; Are provided so as to cover the outer surface of the main block, the main block having a U-shaped cross section serving as the seal diaphragm mounting surface, a donut disk-shaped flange portion having an inner diameter portion connected to an opening of the main block. A cylindrical first cushioning member, a cylindrical second cushioning member provided over the entire surface of the flange portion on the main body block side, the first cushioning member, and the second cushioning member. And a protective cover made of a cylindrical tantalum material with a brim provided so as to cover the second buffer material portion. Differential pressure measuring device, characterized by comprising a sealing diaphragm protrusive diaphragm unit having a diaphragm protrusive diaphragm unit body has. (2) The differential pressure measurement device according to (1), further including a main body block including a cylindrical tube portion and a disk-shaped bottom portion. It is what constituted.

[0024]

In the above construction, the projecting diaphragm unit body is assembled as follows. First,
Assemble the bottom part and the collar part in the cylinder part. The second cushioning member is attached to the collar. The first cushioning member is attached to the outer periphery of the cylindrical portion. A protective cover is attached to the surfaces of the first buffer member and the second buffer member. Integrated with hot isostatic molding. Hereinafter, a detailed description will be given based on embodiments.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram of a main portion of an embodiment of the present invention, FIG. 2 is an explanatory diagram of a main portion of FIG. 1, and FIG.
4 is an assembly drawing of FIG. In the figure, the configuration of the same symbol as FIG. 5 represents the same function. Less than,
Only differences from FIG. 5 will be described.

The projecting diaphragm unit main body 21 includes:
It forms a protruding shape that is convex. Details will be described later. The tantalum sealing diaphragm 22 is provided on one surface of the projection of the protruding diaphragm unit main body 21 via a tantalum sealing ring 23 made of tantalum material. In this case, the tantalum material is welded H and receives pressure of the measurement fluid. This is a tantalum seal diaphragm made of tantalum.

The above-mentioned projecting diaphragm unit main body 2
Reference numeral 1 denotes a main body block 211, a flange 212, a first cushioning member 213, and a second cushioning member 2 as shown in FIGS.
14 and a protective cover 215, and are integrally formed by hot isostatic pressing.

The main body block 211 is a block having a U-shaped cross section whose outer bottom surface serves as a mounting surface for the seal diaphragm 11. In this case, the main body block 211 includes a cylindrical tube portion 2111 and a disk-shaped bottom portion 2112, and is made of stainless steel.

The collar portion 212 has an inner diameter portion connected to the opening of the main body block 211, has a donut shape, and is made of stainless steel. The first cushioning member 213 is provided to cover the outer surface of the main body block 211 and has a cylindrical shape.

The second cushioning member 214 is provided to cover the entire surface of the flange 212 on the side of the main body block 211, and has a cylindrical shape. The protective cover 215 is provided in the first cushioning member 21.
3 and the second cushioning material portion 214 are provided, and are made of a cylindrical cylindrical tantalum material.

Here, the first cushioning member 213 reduces the difference in thermal expansion coefficient between the main body block 211 and the protective cover 215. The second cushioning member 214 reduces the difference in thermal expansion coefficient between the flange 212 and the protective cover 215.

In the above configuration, the projecting diaphragm unit main body 21 is assembled as shown in FIG. First, the bottom part 2112 and the collar part 212 are attached to the cylindrical part 2111.
And assemble.

The second cushioning member 214 is attached to the collar 212. The first cushioning member 213 is attached to the outer periphery of the cylindrical portion 2111. First buffer material portion 213 and second buffer material portion 21
The protective cover 215 is attached to the surface of the substrate 4. Integrated with hot isostatic molding.

As a result, (1) a high quality surface of a tantalum material without a welded portion or a pinhole in a liquid contact portion can be obtained, so that a differential pressure measuring device having good corrosion resistance can be obtained. (2) The surface thickness of the tantalum material can be increased to a thickness that cannot be obtained by other processing methods, specifically, to a thickness of 0.5 to 2.0 mm. A differential pressure measuring device having good proof stress against added scratches can be obtained.

(3) The main body block 211 is
1 and the bottom 2112, the thickness of the bottom 2112 can be freely increased from the cylinder 2111, and a differential pressure measuring device with a high pressure resistance against the measurement fluid can be obtained.

In the above-described embodiment, the type using the capillary tubes 4 and 7 has been described. However, the type in which the diaphragm seal units 5 and 8 are directly attached to the differential pressure measuring device main body 1 is described. Of course, there is an application.

[0037]

As described above in detail, according to the first aspect of the present invention, (1) a high-quality tantalum material surface without a welded portion or a pinhole can be obtained in a liquid contact portion. Thus, a differential pressure measuring device having good corrosion resistance can be obtained. (2) Since the surface thickness of the tantalum material can be increased to a thickness that cannot be obtained by other processing methods, a differential pressure measuring device having improved corrosion resistance and good proof strength against externally applied scratches can be provided. can get.

According to the second aspect of the present invention, since the main body block is constituted by the cylindrical portion and the bottom portion, the thickness of the bottom portion can be freely increased from the cylindrical portion, and the pressure difference with respect to the measurement fluid is high. A pressure measuring device is obtained.

Therefore, according to the present invention, a differential pressure measuring device having corrosion resistance and proof stress can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of an embodiment of the present invention.

FIG. 2 is a detailed view of a main part of FIG. 1;

FIG. 3 is an explanatory diagram of parts shown in FIG. 1;

FIG. 4 is an assembly view of FIG. 3;

FIG. 5 is an explanatory diagram of a configuration of a conventional example generally used in the related art.

FIG. 6 is a detailed view of a main part of FIG. 5;

FIG. 7 is a manufacturing drawing of FIG. 5;

FIG. 8 is a manufacturing drawing of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Differential pressure measuring device main body 2 Main body capsule 3 Cover 4 High pressure side capillary tube 5 High pressure side diaphragm seal unit 6 Filled liquid 7 Low pressure side capillary tube 8 Low pressure side diaphragm seal unit 9 Filled liquid 11 Converter 12 Tantalum seal Diaphragm 13 Seal ring of tantalum 21 Projection type diaphragm unit main body 211 Main body block 2111 Cylindrical part 2112 Bottom part 212 Collar part 313 First buffer part 214 Second buffer part 215 Protective covering

Continued on the front page (72) Inventor Shigeo Nakajima 155 Komurocho, Kofu City, Yamanashi Prefecture Inside the Kofu Office of Yokogawa Electric Corporation

Claims (2)

[Claims] 1. A seal comprising: a protruding diaphragm unit main body having a convex shape; and a seal diaphragm made of a tantalum material provided on one surface of the convex portion via a seal ring made of a tantalum material and receiving a pressure of a measurement fluid. A differential pressure measuring device comprising a diaphragm-projecting diaphragm unit, wherein a U-shaped main body block having an outer bottom surface serving as the seal diaphragm mounting surface, and a donut board shape having an inner diameter portion connected to an opening of the main body block. A first cylindrical cushioning member provided to cover an outer surface of the main body block; and a second cylindrical member provided to cover the entire surface of the main body block on the main body block side. A protective cover made of a cylindrical tantalum material with a brim provided to cover the first buffer material portion and the second buffer material portion. , A differential pressure measuring device, characterized by comprising a sealing diaphragm protrusive diaphragm unit having a diaphragm protrusive diaphragm unit body integrally configured by a hot isostatic pressing process comprises a. 2. The differential pressure measuring device according to claim 1, further comprising a main body block comprising a cylindrical tube portion and a disk-shaped bottom portion.