Explosion proof pressure transmitters, as the core equipment for industrial process pressure measurement, are widely used in flammable and explosive scenarios such as petroleum, chemical, and metallurgical industries. Its safety and stability are directly related to the safe operation of the production system, and correct use and scientific maintenance are key to extending equipment life and ensuring measurement accuracy. The following provides a detailed explanation from three aspects: installation, operation, and maintenance.

1、 Installation standard: Build a strong safety defense line

environmental adaptation
It is necessary to confirm that the installation environment meets the explosion-proof requirements, and the ambient temperature should be controlled within-40℃to65℃Within the scope, avoid direct sunlight or high-temperature radiation sources. The installation location should be far away from the vibration source. If the environmental vibration impact is large, shock absorbers should be installed. For example, when installing around a chemical reactor, the distance from the stirring motor should be selected3Reduce the impact of mechanical vibration on sensors at locations above meters.

Explosion proof wiring
Explosion proof cables must be used for power and signal lines, and must be used for wiringM20×1.5Thread the interface and ensure that the compression nut is tightened to prevent medium infiltration. Before wiring, the power should be cut off. After confirming that there is no voltage using a multimeter, connect according to the wiring diagram24V DCPower supply and4-20mAThe signal line. Special attention should be paid to the explosion-proof surface, which must not be bumped or scratched. After assembly, it should be evenly coated204-1Rust proof oil and tighten the housing screws.

Media compatibility
Select the membrane material based on the characteristics of the tested medium,316LStainless steel diaphragms are suitable for most corrosive media, but in strong acid environments, Hastelloy diaphragms need to be used instead. Before installation, it is necessary to use an aperture measuring instrument to confirm the size of the installation hole, if the deviation exceeds0.1mmIt is necessary to enlarge the hole to prevent sealing failure caused by thread wear.

2、 Key points of operation: Ensure accurate measurement

Parameter Settings
By pressing the button orHARTWhen configuring the protocol, it is necessary to strictly follow the operation code. For example, input“3”Enter the lower range setting, input“6”Start zeroing the main variable. Before zeroing, it is necessary to confirm that the system pressure is stable and the transmitter is in a pressure free state. For wireless transmitters, they can be used throughNB-IoTPlatform setting reporting cycle, default30Communication once per minute, emergency conditions can be shortened to5minute

Range calibration
Use a standard pressure source for calibration, such as0.1Grade precision pressure generator. Preheating is required before calibration30Minutes, press“zero point-range-zero point”Perform three-point verification in sequence. For example, the verification of a certain chemical enterprise5MPaWhen using range transmitters, apply them separately0MPaThe2.5MPaThe5MPaPressure, the recorded output current should be4mAThe12mAThe20mAThe error exceeds±0.1%Adjustments are needed.

3、 Maintenance strategy: Extend equipment lifespan

routine inspection
Check the wiring terminals for looseness every week, and use an infrared thermometer to measure the temperature of the casing every month. If it exceeds85℃Need to investigate overload issues. Clean up impurities in the pressure interface every quarter and use0.5MPaCompressed air blowing to prevent measurement lag caused by blockage.

periodic calibration
It is recommended to12Perform precision calibration once a month, and record the ambient temperature and humidity before calibration. For critical station transmitters, it can be shortened to6Calibrate once a month. Calibration records should include information such as standard instrument number, calibration data, environmental conditions, etc., forming a traceable file.

Fault handling
When there is no output fault, first check24VIs the power supply stable? Use a multimeter to measure the load resistance≤250ΩIf the output is too large, it is necessary to confirm whether the actual pressure exceeds the range and check whether the isolation diaphragm is deformed. For example, a steel plant discovered that its output reached22mAAfter inspection, it was found that the diaphragm had been dented due to the impact of iron filings. After replacing the diaphragm, it returned to normal.

4、 Safety Warning: Strictly abide by the red line of operation

It is strictly prohibited to open the lid with electricity on
Before dismantling the shell in a dangerous place, the power must be cut off and the electricity must be tested to prevent electric sparks from igniting explosive gases. A certain chemical plant once caused arc discharge in the explosion-proof chamber due to uninterrupted operation, resulting in a minor explosion and equipment damage.

Regular replacement of seals
each2Replace once a yearORing, made of fluororubber material, with a temperature resistance range that needs to be covered-40℃to200℃When replacing, apply silicone grease to prevent scratches during assembly.

Explosion proof certification verification
Submit for inspection annuallyCNASQualified institutions confirm the explosion-proof level (such asEx d II C T6）Is it effective. Expired certificates may cause equipment to be disabled during safety inspections.

Through standardized installation, precise operation, and scientific maintenance, explosion-proof pressure transmitters can achieve5Stable operation for over years. According to statistics from a certain petrochemical enterprise, strict implementation of the above methods resulted in a decrease in equipment failure rate67%Reduce annual maintenance costs42%This provides a strong guarantee for safety production.