Precautions for the Selection and Use of Pressure Gauges

Pressure gauges are common measuring instruments that are widely used in various fields. It can intuitively display the pressure changes in each process link, gain insight into the condition formation in the product or medium process, monitor the safety trends in the production and operation process, and build a rapid and reliable safety guarantee through automatic interlocking or sensing devices. It has played an important role in preventing accidents and ensuring the safety of people and property, which is called the "eye" of safety.

1. Precautions for the use of pressure gauges

(1) For pressure gauges installed on boilers and pressure vessels, their range (scale limit value on the dial) should be compatible with the working pressure of the equipment. The range of the pressure gauge is generally 1.5 to 3 times of the working pressure of the equipment, taking 2 times. If the selected pressure gauge range is too large, due to the pressure gauge of the same accuracy, the larger the range is, the larger the allowable error value and the deviation of the naked eye will be, which will affect the accuracy of the pressure reading; on the contrary, if the selected pressure gauge range is too small, the working pressure of the device is equal to or close to the scale limit of the pressure gauge, which will cause the elastic part in the pressure gauge to be in a long-term deformed state, which is easy to deform, causing the error of the pressure gauge to increase and the service life of the pressure gauge to decrease. In addition, in the case that the range of the pressure gauge is too small, if the over-pressure operation happens, the pointer crosses the upper limit and approaches 0, which will cause the operator to have an illusion with greater accidents followed. Therefore, the operating pressure range of different types of pressure gauges should not exceed 60-70% of the scale limit.

(2) The accuracy of the pressure gauge is expressed as a percentage of the allowable error to the limit value of the dial scale. The accuracy level is generally marked on the dial. When selecting a pressure gauge, the accuracy should be determined according to the pressure level of the equipment and actual work needs.

(3) In order to enable the operator to accurately see the pressure value, the dial diameter of the pressure gauge should not be too small. If the pressure gauge is installed higher or far away from the post, the dial diameter should be increased.

(4) If the medium used by the pressure gauge for measurement is corrosive, then different elastic element materials must be selected according to the specific temperature, concentration and other parameters of the corrosive medium, otherwise the expected purpose will not be achieved.

(5) Pay attention to daily use and maintenance, regularly check, clean and keep records of usage.

2. Use and maintenance of pressure gauge

(1) It must be vertical: use a 17mm wrench to tighten it when installing, and not force the case to be twisted; collisions should be avoided during transportation.

(2) The temperature of the surrounding environment for the use of it should be -25~55℃.

(3) The working environment vibration frequency is less than 25HZ, and the amplitude is not more than 1mm.

(4) During use, due to the high ambient temperature, the indicating value of it does not return to 0 or shows the indicating error, you can cut the sealing rubber plug on the upper part of the case to make the inner cavity of the instrument connect with the atmosphere.

(5) The scope for it to use should be between 1/3 and 2/3 of the upper limit.

(6) Isolation device should be added when measuring medium that is corrosive, may crystallize, or with high viscosity.

(7) It should be checked frequently (at least once every three months), and repairs should be made in time if any malfunction is found.

(8) From the date of leaving the factory, if it is found to be invalid or damaged due to poor manufacturing quality under normal storage and use conditions within half a year, the company will be responsible for repair or replacement.

(9) If it is used for measuring corrosive media, the required conditions should be indicated when ordering.

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