Y-100B/ZN/MF/316, Y-100B/ZN/MF/316L, Y-100B/ZN/MF/Ta, Y-100B/ZN/MF/HC, Y-100B/ZN/MF/F4, Y-100B/ZN/MF/316+F4, Y-100B/SR/MF/316, Y-100B/SR/MF/316L, Y-100B/SR/MF/Ta, Y-100B/SR/MF/HC, Y-100B/SR/MF/F4, Y-100B/SR/MF/316+F4, Y-100B/YL/MF/316, Y-100B/YL/MF/316L, Y-100B/YL/MF/Ta, Y-100B/YL/MF/HC, Y-100B/YL/MF/F4, Y-100B/YL/MF/316+F4, Y-100B/RL/MF/316, Y-100B/RL/MF/316L, Y-100B/RL/MF/Ta, Y-100B/RL/MF/HC, Y-100B/RL/MF/F4, Y-100B/RL/MF/316+F4, Y-100B/GL/MF/316, Y-100B/GL/MF/316L, Y-100B/GL/MF/Ta, Y-100B/GL/MF/HC, Y-100B/GL/MF/F4, Y-100B/GL/MF/316+F4, Y-100B/MG/316, Y-100B/MG/316L, Y-100B/MG/Ta, Y-100B/MG/HC, Y-100B/MG/F4, Y-100B/MG/316+F4, Y-100B/ML/316, Y-100B/ML/316L, Y-100B/ML/Ta, Y-100B/ML/HC, Y-100B/ML/F4, Y-100B/ML/316+F4, Y-100B/MZ/316, Y-100B/MZ/316L, Y-100B/MZ/Ta, Y-100B/MZ/HC, Y-100B/MZ/F4, Y-100B/MZ/316+F4, Y-100B/MH/316, Y-100B/MH/316L, Y-100B/MH/Ta, Y-100B/MH/HC, Y-100B/MH/F4, Y-100B/MH/316+F4, Y-100B/MC/316, Y-100B/MC/316L, Y-100B/MC/Ta, Y-100B/MC/HC, Y-100B/MC/F4, Y-100B/MC/316+F4, Y-100B/MN/316, Y-100B/MN/316L, Y-100B/MN/Ta, Y-100B/MN/HC, Y-100B/MN/F4, Y-100B/MN/316+F4, Y-150B/ZN/MF/316, Y-150B/ZN/MF/316L, Y-150B/ZN/MF/Ta, Y-150B/ZN/MF/HC, Y-150B/ZN/MF/F4, Y-150B/ZN/MF/316+F4, Y-150B/SR/MF/316, Y-150B/SR/MF/316L, Y-150B/SR/MF/Ta, Y-150B/SR/MF/HC, Y-150B/SR/MF/F4, Y-150B/SR/MF/316+F4, Y-150B/YL/MF/316, Y-150B/YL/MF/316L, Y-150B/YL/MF/Ta, Y-150B/YL/MF/HC, Y-150B/YL/MF/F4, Y-150B/YL/MF/316+F4, Y-150B/RL/MF/316, Y-150B/RL/MF/316L, Y-150B/RL/MF/Ta, Y-150B/RL/MF/HC, Y-150B/RL/MF/F4, Y-150B/RL/MF/316+F4, Y-150B/GL/MF/316, Y-150B/GL/MF/316L, Y-150B/GL/MF/Ta, Y-150B/GL/MF/HC, Y-150B/GL/MF/F4, Y-150B/GL/MF/316+F4, Y-150B/MG/316, Y-150B/MG/316L, Y-150B/MG/Ta, Y-150B/MG/HC, Y-150B/MG/F4, Y-150B/MG/316+F4, Y-150B/ML/316, Y-150B/ML/316L, Y-150B/ML/Ta, Y-150B/ML/HC, Y-150B/ML/F4, Y-150B/ML/316+F4, Y-150B/MZ/316, Y-150B/MZ/316L, Y-150B/MZ/Ta, Y-150B/MZ/HC, Y-150B/MZ/F4, Y-150B/MZ/316+F4, Y-150B/MH/316, Y-150B/MH/316L, Y-150B/MH/Ta, Y-150B/MH/HC, Y-150B/MH/F4, Y-150B/MH/316+F4, Y-150B/MC/316, Y-150B/MC/316L, Y-150B/MC/Ta, Y-150B/MC/HC, Y-150B/MC/F4, Y-150B/MC/316+F4, Y-150B/MN/316, Y-150B/MN/316L, Y-150B/MN/Ta, Y-150B/MN/HC, Y-150B/MN/F4, Y-150B/MN/316+F4 diaphragm pressure gauge consists of a diaphragm isolator and a universal pressure gauge that forms a system diaphragm. Diaphragm pressure gauges and equipment connection methods mainly include screw connection and flange connection and sanitary clamp type. The table is suitable for measuring the medium pressure of strong corrosion, high temperature, high viscosity, easy crystallization, easy solidification, solid float, and the need to avoid the measurement medium directly entering the universal pressure gauge and preventing sediment accumulation and easy cleaning. Diaphragm pressure gauges are mainly used for the flow medium fluid pressure in the production process of petrochemical, alkali, chemical fiber, dyeing, pharmaceutical, food and cheese industries.
The working principle of the diaphragm pressure gauge is shown in the figure. The diaphragm pressure gauge consists of a diaphragm isolator and a universal pressure gauge. It is a system pressure gauge. The spring tube is vacuumed by special equipment and filled with liquid. The sheet seals the diaphragm. When the pressure P of the measured medium acts on the diaphragm to deform it, the working fluid filled in the compression system is formed so that the working fluid forms a ΔP equivalent to P, by means of work. The conduction of the liquid causes the free end of the elastic element (spring tube) in the pressure gauge to produce a corresponding elastic deformation-displacement, and then displays the measured pressure value according to the working principle of the pressure gauge matched thereto.
Temperature characteristics of the diaphragm pressure gauge: Since the diaphragm pressure gauge system is filled with the sealing liquid as the medium for transmitting the pressure, the pressure gauge increases the temperature of the pressure receiving portion due to the temperature expansion coefficient of the sealing liquid, and The influence of temperature is related to the expansion coefficient of the sealing body, the stiffness of the diaphragm and the pressure of the pressure, especially for the low-range pressure instruments. Generally, the temperature error of the pressure receiving portion is not more than 0.1%/degree, so the total temperature influence of the diaphragm pressure gauge is generally the sum of the temperature influence amount of the universal meter and the temperature influence of the pressure portion of the diaphragm device.
Before installing the diaphragm pressure gauge, carefully check the model, diaphragm material and measuring range to check whether the diaphragm is bumped. When there is no pressure, the pressure gauge indicates whether it is at zero position, find the cause, re-adjust, and Only after passing the test can it be used. The procedure for calibrating the diaphragm pressure gauge is the same as verifying the conventional pressure gauge, and will not be repeated again. The main points are as follows:
(1) Before the calibration, firstly prepare the matching joint according to the model of the diaphragm device of the diaphragm pressure gauge to be used in the general pressure calibration table. The diaphragm device of the diaphragm pressure gauge is generally flanged. According to the size and type of the flange, the matching pressure fittings can be prepared, and the corresponding flanges and universal pressure gauge joints can be found in the field for processing, which is the most direct and convenient method.
(2) Pay attention to the process of fixing the diaphragm pressure gauge in the standard calibration table: gently handle it, do not touch the diaphragm. When using the wrench to rotate the diaphragm pressure gauge, the wrench must be stuck. The connecting nut of the diaphragm device is not stuck on the universal pressure gauge. Because the universal pressure gauge and the diaphragm device on the instrument are a sealing system, the pressure gauge should not be dismantled or replaced, so as to prevent the working fluid filled inside the system from leaking. The impact on performance and even scrap, especially for new students who have just joined the work, must be explained before the diaphragm pressure gauge is verified.
(3) Result processing: In the process of boosting, if compared with the standard table, if it is out of tolerance, first check whether there is oil leakage, sealing, etc. If there is oil leakage and the seal is not good, it can only be returned to the factory for treatment or scrapped; if not In the above situation, the indicator pin can be removed and the indicator pin can be re-set. The long-term experience is that it is generally reasonable to re-fix the needle at 1/2 of the range when the needle is fixed; if it is still too poor, it can only be degraded or scrapped.
Before using the diaphragm pressure gauge, be sure to understand the characteristics of the medium being monitored. Because the diaphragm pressure gauge is designed for special media, when monitoring general gas, water and oil pressure, you can use a general pressure gauge when monitoring. When the pressure of nitric acid, phosphoric acid or strong alkali is used, stainless steel pressure gauge can be used, but when the medium to be monitored is highly corrosive, such as: hydrochloric acid, wet chlorine, ferric chloride; has a high viscosity such as: latex; easy to crystallize such as: Brine; easy to solidify such as: hot asphalt; there are solid floats such as: sewage, the above pressure gauge is not acceptable, because SUS316 stainless steel pipe will be corroded by hydrochloric acid, asphalt and sewage floats will also block the pressure guide hole of the pressure gauge And make the pressure gauge lose its function. Because the diaphragm pressure gauge has a diaphragm diaphragm, it can prevent the high-viscosity, easy-to-crystallize, and easily solidified medium from flowing into the pressure guiding hole, ensuring that the pressure gauge reading can normally reflect the pressure of the measured medium.
There are several points to note when using the diaphragm pressure gauge:
(1) The installation position of the diaphragm pressure gauge must correspond to the installation position in the precautions of the pressure gauge instruction manual.
(2) The pressure gauge should be selected according to the nature of the tested medium to select the appropriate interface form, diaphragm material, gasket material. When there is strong mechanical vibration and medium pressure pulsation, it is required to use anti-vibration pressure gauge. When pressure gauges are used, the valve should be opened slowly and evenly.
1. When there is pressure, the pointer has no indication
The reason for this failure is that the connection between the pointer and the sun gear shaft is loose due to strong vibration, and the displacement of the spring tube after the pressure cannot deflect the pointer. Secondly, the silicone oil in the spring tube is lost too much and the pressure cannot be transmitted.
2, the measurement pressure is not accurate, the low end has a pressure indication change, the pressure does not change the pointer does not change
The reason for this failure is that a small amount of silicone oil in the spring tube is lost, allowing air to enter, because the gas can be compressed, so when the pressure increases, the pressure indicated by the pointer is not allowed or does not work.
3. In the process of pressure measurement, the pointer changes in a jump
This kind of failure often occurs when the diaphragm pressure gauge is in a large vibration (such as the outlet pressure of the pump). Due to the fluctuation of the pressure, the pointer also swings back and forth, causing the center gear of the pressure movement core to be seriously worn, the center gear and the fan shape. The gears are not well matched, resulting in a jump in the pointer. For the jump fault handling of the pointer, the worn central gear portion can be repaired by scraping with a small assorted file and a scrap saw blade. When the shaft hole of the pointer becomes larger, it can be tapped with a small hammer to make it contract until the pointer can be tightly coupled with the center gear shaft.