|
 overview
|
|
Diaphragm pressure gaugeIn order to expand the range of use of various general-purpose pressure instruments, which can be used to measure the pressure of media with strong corrosion, high temperature, high viscosity, easy crystallization, easy solidification, and solid suspended matter, as well as for pressure detection in situations where certain measuring media cannot directly enter the general-purpose instrument and are easy to clean and prevent sediment accumulation, a diaphragm gauge composed of a diaphragm isolator and a general-purpose pressure instrument system must be used.
Diaphragm gauges are mainly used for pressure detection in the production processes of industrial sectors such as petroleum, chemical, pharmaceutical, food, and textile.
|
|
Structural principle
|
|
Diaphragm pressure gaugeA closed system consisting of various universal pressure instruments and diaphragm isolators of different structures, filled with sealing fluid. When the pressure of the measured medium acts on the diaphragm, the diaphragm deforms and compresses the sealing liquid in the closed system. Due to the inherent properties of the sealing fluid, the elastic elements in the pressure instrument undergo corresponding elastic deformation and displacement, and the pressure value is displayed by the indicator device. When the stiffness of the diaphragm is small enough, the pressure indicated by the pressure gauge is close to the pressure value of the measured medium.
|
|
Type Designation
|
|
|
|
System composition diagram
|
|
|
|
Sketch Map
|
|
Accuracy: ± 1.6%, ± 2.5%.
Diaphragm material: OCr18Ni12MO2(316)， Hastelloy C (H276c), Monel alloy (Cu30Ni70), Tantalum alloy (Ta), fluoroplastic (F4).
Isolator material: acid resistant stainless steel, molybdenum containing stainless steel, fluoroplastic.
Sealing gasket material: nitrile rubber, fluoroplastic.
Sealing fluid: silicone oil, vegetable oil
Execution standards: JB/T8624-97
|
|
|
Specification
|
●Diaphragm pressure gaugeTemperature characteristics
Due to the filling of sealing liquid as a pressure transmission and medium in the system of the diaphragm meter, the temperature effect of the diaphragm meter is related to the expansion coefficient of the sealing liquid, the stiffness of the diaphragm, and the temperature of the compressed part. The impact on low range pressure instruments is particularly evident. The temperature error of the general pressure part is not greater than 0.1%/℃, so the temperature effect of the diaphragm gauge is generally the sum of the temperature effect of the general pressure instrument and the temperature effect of the pressure part of the diaphragm isolator.
● Level difference of diaphragm gauge |
|
Especially for diaphragm gauges with flexible connecting pipes, due to the fact that the diaphragm pressure receiving part is not installed on the same horizontal plane as the universal pressure gauge, there will be a liquid level difference and an impact quantity △ P. Pay more attention to precise measurement.
●Diaphragm pressure gaugeCorrosion resistance
The diaphragm gauge and corrosion resistance can be ensured by selecting appropriate materials for the diaphragm, flange, and sealing gasket in contact with the measuring medium.
Diaphragm material: 0Cr17Ni12Mo2 (316); Monel gold (Cu30Ni70); Ha Shi Quan Jin (H276C); Tantalum (Ta) and fluoroplastic (F4).
Flange material: Stainless steel 0Cr17Ni12Mo2 (316); Stainless steel lined with fluoroplastic (316+F4).
Sealing gasket material: * * * rubber; Fluororubber; Silicone rubber and fluoroplastics.
● Selection of diaphragm fluid
To ensure the reliability and safety of diaphragm meters, suitable sealing liquids should be selected according to different applications.
|
|
|
△P=d.H
H-liquid level difference
Specific gravity of d-sealing fluid |
| Sealing fluid |
Temperature range of the compressed part |
Specific gravity g/cm³
|
Body expansion coefficient 1/℃ |
purpose |
| High viscosity silicone oil |
-10～200℃ |
1.07 |
0.95×10-³
|
High temperature use |
| Low viscosity silicone oil |
-30～100℃ |
0.94 |
1.08×10-³
|
Generally used |
| Glycerol aqueous solution |
-5～100℃ |
1.27 |
0.61×10-³
|
Food use |
| vegetable oil |
-5～100℃ |
0.93 |
1.03×10-³
|
Food use |
| Fluoro oil |
-30～150℃ |
1.93 |
0.75×10-³
|
Hydrogen, oxygen |
|
|
Example of Model Marking
|
Tag 1: Y-100B/SR/MF（A）/316/4PMa/50- 4.0HGJ46
The universal instrument is a Y-100A stainless steel pressure gauge, connected in SR heat dissipation type, using an open convex flange MF, the isolator (flange) material is carbon steel, the diaphragm material is 316 stainless steel, and the measurement range is 0-4.0MPa. Flange standard 50-4.0HGJ46.
Tag 2: YSG-2/Z/MG (B)/Ha/1MPa/20-4.0HGJ47
The universal instrument is YSG-2 inductive pressure transmitter, with direct connection and I-shaped flange MG. The isolator (flange) material is 1Cr18Ni9, and the diaphragm material is Hastelloy all metal. The measurement range is 0-1MPa, and the flange standard is 20-4.0HGJ47. |
|
Diaphragm device flange size
|
| 1. Open convex flange unit: mm |
|
code
|
Range upper limit value P（MPa）
|
Recommended flange standard code |
Flange connection
|
dimension |
|
D
|
K
|
d
|
f
|
L
|
C |
B |
| MF1 |
4 |
JIS-10/20K 50A |
155 |
120 |
100 |
3 |
19 |
18 |
50 |
Figure 1 |
|
4 |
50-1.0/4.0HGJ46
|
160 |
125 |
100 |
3 |
19 |
18 |
50 |
|
4 |
ANSI-2B 150Ib |
152 |
121 |
92.1 |
3 |
19 |
18 |
2" |
|
4 |
ANSI-2B 300/100Ib |
165 |
127 |
92.1 |
3 |
19 |
18 |
2" |
| 6~10 |
25-10.0HGJ47 |
125 |
89 |
50.8 |
7 |
20 |
20 |
25 |
Figure 2 |
| 6~10 |
25-10.0HGJ47 |
165 |
127 |
92.1 |
3.5 |
20 |
26 |
50 |
| 16~25 |
20-25.0HGJ53 |
130 |
89 |
43 |
7 |
22 |
20 |
25 |
| MF |
4 |
25-4.0DIN |
115 |
85 |
65 |
3 |
M12 |
26 |
25 |
Figure 3 |
|
| Can be manufactured according to the flange standard size provided or specified by the user |
|
Figure 1 (P ≤ 4MPa) [code MF1]
Figure 2 (6MPa ≤ P ≤ 25MPa) [code MF1]
Figure 3 (P ≤ 4MPa) [code MF]
|
2. I-shaped convex flange [code MG]
Range upper limit value: ≤ 4MPa |
|
Standard flange
STANDARD
|
Flange connection
|
| Dn |
d1 |
K |
d2 |
L |
| JSI-10/25K 25A |
25 |
125 |
90 |
70 |
19 |
| JSI-10/20K 20A |
20 |
100 |
72 |
58 |
15 |
| JSI-10/20K 15A |
15 |
95 |
70 |
52 |
15 |
| ANSI-1B-15Ib |
1" |
108 |
79.4 |
50.8 |
15.7 |
| ANSI-1B-300/600Ib |
1" |
124 |
88.9 |
50.8 |
19.1 |
| 20-1.0/4.0HGJ47 |
20 |
105 |
105 |
56 |
14 |
|
3. Threaded joint type [ML]
Range upper limit value: ≤ 60MPa
|
4. Bolt type diaphragm isolator [code MZ]
Measurement range: 1-25MPa
Diaphragm and diaphragm seat material: 0Cr17Ni12Mo2 [316]
|
|
5. Clamp type diaphragm isolator [code MC]
6. Nut type diaphragm isolator [code MN]
7. Rectangular flange diaphragm isolator [code MH]
pour5, 6, 7, all refer to the dedicated page for sanitary diaphragm pressure gauges. |
|
Type and size of connector
|
|
Damper (Z)
|
Angular (G)
|
Heat sink (S)
|
|
|
|
|
|
|
|
