JP5831065B2 - Differential pressure / pressure gauge - Google Patents

Description

  The present invention relates to a differential pressure / pressure gauge, and in particular, when measuring the differential pressure / pressure using a diaphragm, the differential pressure is obtained by delaying the rate at which hydrogen contained in the fluid to be measured permeates the diaphragm and enters the sealed liquid. -Regarding pressure gauges.

  3A and 3B show a differential pressure / pressure gauge to which the present invention is applied, FIG. 3A shows an overview of the differential pressure gauge, and FIG. 3B shows a front view of the pressure gauge. FIG. 3C is an enlarged cross-sectional view of the liquid contact block, and FIG. 3D is an enlarged cross-sectional view of part A of FIG.

The differential pressure / pressure gauge measures the pressure and differential pressure of the fluid to be measured by converting the pressure of the fluid to be measured (gas or liquid) into the displacement of the diaphragm.
In FIG. 3A, 21a (high pressure side) and 21b (low pressure side) are a pair of diaphragm seals constituting a differential pressure gauge. Each diaphragm seal has liquid contact blocks 1a and 1b, and the peripheral portions of the diaphragms 5a and 5b are fixed to one surface of these liquid contact blocks by welding. Flange 9a, 9b is fixed to the outer periphery of these liquid contact blocks, and one ends of capillary tubes 10a, 10b are connected to the side surfaces of the liquid contact blocks, respectively, and the other ends of these capillary tubes are connected to the transmitter body 20. It is connected to the cover flange 22 which comprises.

  As shown in FIGS. 3C and 3D, each of the liquid contact blocks 1a and 1b includes a sensor chamber 2 formed in a curved surface, a pressure transmission unit 3 formed in a predetermined diameter that conducts to the sensor chamber, and a sensor chamber. 2 and the measured fluid B side are sealed, a seal ring 6 that locks the peripheral edge of the diaphragm, and a sealed liquid filled in the sensor chamber 2 sealed by the diaphragm 5 7.

  The seal ring 6 has a structure in which a welded portion 8 is provided in which the diaphragm 5 is sandwiched between the liquid contact block 1 and joined by welding. On the opposite side of the surface of the diaphragm 5 in contact with the fluid B to be measured, that is, the surface in contact with the sealing liquid 7, a gold plating 5 a is applied to the entire surface.

In the differential pressure / pressure gauge having such a structure, the diaphragm 5 is used at the portion in contact with the fluid to be measured, and only the pressure is transmitted to a sensor (not shown) via the sealing liquid 7.
Here, in the case where hydrogen molecules are contained in the fluid B to be measured, a gold plating 5a or a ceramic coating is applied to the surface of the surface that is not in contact with the fluid B to be measured in order to prevent adverse effects due to the hydrogen molecules that have passed through the diaphragm 5. The permeation of hydrogen molecules is suppressed.

JP 2002-071494 A JP 2002-156301 A

  However, in the above-described prior art, when the object B to be measured includes hydrogen molecules, as shown in FIG. 4A, even if the diaphragm is subjected to gold plating or ceramic coating for preventing the permeation of hydrogen molecules, the sensor Hydrogen molecules permeate through the membrane of the diaphragm 5, which is a partition wall with the chamber 2, and gaseous hydrogen remains in the sensor chamber 2. In the case of measurement at a low pressure in the sensor chamber, this permeated hydrogen molecule expands to generate bubbles in the worst case, and the diaphragm film is deformed to change the pressure in the sensor chamber 2 and the measured value to hydrogen. There is a problem that an error based on the transmission of molecules occurs.

Therefore, as shown in FIG. 4B, the second welded portion 8a is welded, and the gold plating 5a is applied so as to include this welded portion, so that the portion where hydrogen enters from the diaphragm 5 is eliminated. is there.
However, when hydrogen permeation is intense, even in such a structure, as shown by the arrow c in FIG. 4 (c), hydrogen may enter from the welded portion, and the transmitter may not be used immediately.

  Accordingly, an object of the present invention is to provide a differential pressure / pressure gauge having a structure that delays permeation of hydrogen molecules that permeate through a diaphragm and a weld.

In order to solve the above problems, a differential pressure / pressure gauge according to the present invention is as follows.
A wetted block formed in a disc shape;
Donut-shaped seal ring,
A diaphragm having an outer diameter smaller than the outer diameter of the seal ring and larger than the inner diameter, and having one surface plated with gold;
In the differential pressure / pressure gauge with
The diaphragm is welded to one side of the seal ring from a gold-plated side at a plurality of locations having different diameters,
The seal ring is welded to the wetted block from the other surface outside the outer diameter of the diaphragm, and a groove is formed between a plurality of welding locations having different diameters.

In claim 2,
A wetted block formed in a disc shape;
Donut-shaped seal ring,
A diaphragm having an outer diameter smaller than the outer diameter of the seal ring and larger than the inner diameter, and having one surface plated with gold;
In the differential pressure / pressure gauge with
The diaphragm is welded to one surface of the seal ring from the gold-plated side, and a groove having a predetermined diameter is formed in the seal ring so as to be covered by the gold-plated portion outside the welded portion. is, the groove is embedded is member capable of adsorbing and storing hydrogen, characterized in that the other surface of the seal ring and welding the wetted blocks outside than the outer diameter of the diaphragm.

In Claim 3, in the differential pressure / pressure gauge according to claim 2,
The member capable of adsorbing and storing hydrogen includes Ni or Ni alloy .

According to claim 1 of the differential pressure / pressure gauge of the present invention,
This diaphragm is welded from the gold-plated side of the diaphragm to one surface of the seal ring at a plurality of locations with different diameters, and the other surface of the seal ring is welded to the wetted block outside the outer diameter of the diaphragm. Since a groove is formed between the plurality of welds, hydrogen that has passed through the welded part of the inner periphery of the seal ring and diaphragm passes through the space between the welded part and the welded part of the outer peripheral part. Invades and stays in the liquid side. As a result, it is possible to delay the time until hydrogen bubbles are generated in the sealing liquid.

According to claims 2 and 3,
The gold-plated side of the diaphragm is welded to one surface of the seal ring, and the seal ring has a predetermined diameter so that it is covered with the gold-plated portion outside the welded portion.
Groove is formed, on the groove are embedded member capable of adsorbing and storing hydrogen, because the other surface of the seal ring was welded to wetted block outside than the outer diameter of the diaphragm, it has passed through the weld First, hydrogen accumulates in a metal that can adsorb and store hydrogen, and after the metal cannot accumulate hydrogen, hydrogen enters the sealing liquid.
As a result, it is possible to delay the time until hydrogen bubbles are generated in the sealing liquid.

It is principal part sectional drawing which shows one Example of the diaphragm seal part of the differential pressure and pressure gauge of this invention. It is principal part sectional drawing which shows the other Example of the diaphragm seal part of the differential pressure and pressure gauge of this invention. It is the general view (a) of the conventional differential pressure gauge, the front view (b) of a pressure gauge, the enlarged view (c) of a diaphragm seal part, and the A section expansion of the (c) figure. It is principal part sectional drawing which shows the hydrogen penetration | invasion path | route in the conventional diaphragm seal part.

  FIG. 1 is a cross-sectional view of an essential part showing an example of an embodiment of a diaphragm seal portion of a differential pressure / pressure gauge of the present invention. In FIG. 1, reference numeral 1 denotes a disc-shaped liquid contact block, and a circular recess 1c is formed at the center of one surface. Reference numeral 6 denotes a donut-shaped seal ring, in which a ring-shaped groove 11 is formed near the inner periphery of one surface.

  Reference numeral 5 denotes a diaphragm having one surface plated with gold. The outer diameter of the diaphragm is smaller than the outer diameter of the seal ring 6 and larger than the inner diameter. And this diaphragm is made into the state which covered the ring-shaped groove | channel 11 formed in the said seal ring by the side (liquid-contact side) which is not gold-plated, and the inner side (2nd welding part) of the said ring-shaped groove | channel 11 8b) and the outside (third weld 8c) are welded to the seal ring 6. As a result, the ring-shaped groove 11 is airtightly closed by the surface of the diaphragm 5.

Thus, the seal ring 6 to which the diaphragm 5 is welded is inserted so that the gold-plated (non-wetted) side is in contact with the bottom of the concave portion 1c of the wetted block formed in the circular shape.
In the inserted state, one surface of the liquid contact block 1 and the other surface of the seal ring are flush with each other.
In this state, the other surface of the seal ring outside the outer periphery of the diaphragm is fixed to the wetted block by welding (first welding portion 8a).

According to the structure of the diaphragm seal portion of the differential pressure / pressure gauge described above, the groove 11 functions as a hydrogen reservoir even if hydrogen contained in the measurement object permeates from the welded portion on the inner peripheral side of the groove, and fills it. The hydrogen thus permeated the sealed liquid side through the welded portion (third welded portion 8c) on the outer peripheral side of the groove.
As a result, it is possible to delay the time until hydrogen bubbles are generated in the sealing liquid.

FIG. 2 is a cross-sectional view of an essential part showing an embodiment in claim 2. 2 is different from FIG. 1 in that a metal (for example, Ni or Ni alloy) 12 capable of adsorbing hydrogen is embedded in the seal ring 6.
In FIG. 2, 1 is a disk-shaped liquid contact block, and a circular recess 1c is formed at the center of one surface. Reference numeral 6 denotes a donut-shaped seal ring having a groove 11a formed on one surface, and Ni or an Ni alloy capable of adsorbing hydrogen is embedded in the groove flush with one surface of the seal ring.

  Reference numeral 5 denotes a diaphragm having one surface plated with gold. The outer diameter of the diaphragm is smaller than the outer diameter of the seal ring 6 and larger than the inner diameter. This diaphragm is in a state where Ni or Ni alloy formed on the seal ring 6 is partially covered with the gold-plated side (wetted side) and welded to the weld seal ring inside the groove 11a. (Second welded portion 8b).

  Further, the outer peripheral portion of the diaphragm 5 partially covered with Ni or Ni alloy is also welded (third welded portion 8c), and the outer periphery of the Ni or Ni alloy portion is welded to the seal ring (fourth welded portion 8d). . The seal ring 6 is inserted into the recessed portion 1c of the wetted block with the Ni or Ni alloy portion embedded side down and welded to the wetted block 1 from the other surface (first welded portion 8a).

  According to the structure of the diaphragm seal portion of the differential pressure / pressure gauge described above, hydrogen that has permeated through the welded portion first accumulates in a metal that can adsorb and store hydrogen, and the metal fills the metal and accumulates hydrogen. After that, hydrogen enters the sealed liquid. As a result, it is possible to delay the time until hydrogen bubbles are generated in the sealing liquid.

The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention.
Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

DESCRIPTION OF SYMBOLS 1 Liquid contact block 2 Sensor chamber 3 Pressure transmission part 5 Diaphragm 6 Seal ring 7 Filled liquid 8 Welding part 9 Flange 10 Capillary tube 11 Groove (Holding space)
12 Metal that can adsorb hydrogen (Ni or Ni alloy)
20 Transmitter body 21 Diaphragm seal 22 Cover flange

Claims (3)

A wetted block formed in a disc shape;
Donut-shaped seal ring,
A diaphragm having an outer diameter smaller than the outer diameter of the seal ring and larger than the inner diameter, and having one surface plated with gold;
In the differential pressure / pressure gauge with
The diaphragm is welded to one side of the seal ring from a gold-plated side at a plurality of locations having different diameters,
The seal ring is welded to the wetted block from the other surface outside the outer diameter of the diaphragm, and a groove is formed between a plurality of welding locations having different diameters. Total. A wetted block formed in a disc shape;
Donut-shaped seal ring,
A diaphragm having an outer diameter smaller than the outer diameter of the seal ring and larger than the inner diameter, and having one surface plated with gold;
In the differential pressure / pressure gauge with
The diaphragm is welded to one surface of the seal ring from the gold-plated side, and a groove having a predetermined diameter is formed in the seal ring so as to be covered by the gold-plated portion outside the welded portion. is, differential pressure-in groove, characterized in that welded the wetted blocks are embedded member capable of adsorbing and storing hydrogen, than the outer diameter of the diaphragm from the other surface of the sealing ring on the outside Pressure gauge. The differential pressure / pressure gauge according to claim 2, wherein the member capable of adsorbing and storing hydrogen includes Ni or a Ni alloy .

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