Press gauge's points for attention

High accuracy pressure gauge's precautions for use

1. The instrument must be vertical: during installation, a 17mm wrench should be used to tighten it, and the case should not be forced to twist; Avoid collision during transportation;

2. The instrument should be used at the ambient temperature of - 25 ~ 55 ℃;

3. The vibration frequency in the working environment is less than 25Hz and the amplitude is no more than 1mm;

4. During use, due to the high ambient temperature, the indicated value of the instrument does not return to zero or the indicated value exceeds the difference, the sealing rubber plug on the upper part of the watch case can be cut off to connect the inner cavity of the instrument with the atmosphere;

5. The application range of the instrument shall be between 1 / 3 and 2 / 3 of the upper limit;

6. Isolation device shall be added for measuring corrosive medium, medium that may crystallize and medium with high viscosity;

7. The instrument shall be verified frequently (at least once every three months). In case of any fault, it shall be repaired in time.

High accuracy pressure gauge's installation mode

According to the threaded joint and installation method, the instruments in article 4.1.2 of the national standard of pressure gauge general pressure gauge GB / t1226-2001 are divided into direct installation pressure gauge, embedded (panel mounted) pressure gauge and convex (wall mounted) pressure gauge.

1. The installation position of the pressure gauge shall meet the requirements of the installation state. Generally, the dial shall not be placed horizontally. The height of the installation position shall be convenient for the staff to observe.

2. The distance between the installation position of the pressure gauge and the pressure measuring point shall be as short as possible to ensure good sealing and no leakage.

3. There shall be a buffer at the front end of the installed pressure gauge; In order to facilitate inspection, a shut-off valve shall be installed under the instrument; When the medium is dirty or has pulse pressure, filter, buffer and stabilized pressure gas can be used.

High accuracy pressure gauge's corrosion prevention

Corrosion protection of shell:

1. The service environment is corrosive gas, etc. it is recommended that the shell be made of stainless steel or sprayed with Teflon, so as to prolong the service life of the pressure gauge;

2. It is recommended to improve the protection grade of the shell to prevent external moisture from entering the gauge and improve the service life of the pressure gauge.

Anti corrosion of liquid receiving part:

1. For general corrosive media, if the stainless steel elastic element can withstand corrosion for 1 ~ 2 years, the general stainless steel pressure gauge can be selected. During installation, the impulse pipe shall be short, and if necessary, the buffer coil shall be changed to buffer tank to prevent impurities from blocking.

2. If the medium corrodes stainless steel and copper, the buffer tank can be changed to isolation tank and add corrosion-resistant isolation liquid. The type of liquid barrier can be selected according to the nature of the measured medium, but it is better to use it for more than half a year without deterioration. If the ordinary isolation liquid is not applicable, fluorine chlorine oil can be used as the isolation liquid, but the price is very expensive. Therefore, the isolation tank should be small, and the fluorine oil should be recycled for reuse during disassembly and assembly.

3. Diaphragm pressure gauge can be used, including molybdenum containing stainless steel, Hastelloy and tantalum sheet. Methyl silicone oil is used to transmit pressure between the diaphragm and ballistic tube, and the minimum range can be 0 ~ 100KPA. If the diaphragm material is not corrosion resistant, a layer of F46 (polyperfluoroethylene propylene) diaphragm can be added, but the sensitivity bottom of the instrument and meter is reduced. F46 can also be directly used as the isolation diaphragm, but pay attention to the permeability of the medium. Fluorine oil can be used as the transfer fluid for high temperature and oil prohibited media.