Explosion-proof electric contact pressure gauge:Industrial explosion-proof application scenarios, core advantages and selection guide for all aspects.

                    Core application scenarios
                    
Flammable and explosive gas/dust environment                    
· Petrochemical industry: Pressure monitoring for reaction vessels, storage tanks, and pipelines (such as natural gas, liquefied petroleum gas)                     
·Coal mining/metal industry: Underground gas pipelines, pressure control in dust workshops (to prevent dust explosions)                     
·Pharmaceutical / Coating Workshop: Pressure alarm for solvent storage tanks and spray painting equipment (to prevent explosion of volatile gases)                    
                    
Automated control scenarios                    
·Pressure linkage control: When the pressure reaches the preset value, the electrical contacts will trigger the operation of the pump, valve or alarm (such as the start or stop of the fire suppression pressure stabilizing pump)                     
·Industrial process monitoring: Steam boiler pressure protection (automatically cuts off the heat source in case of overpressure, and overloading protection for the compressor.)                    
                    
                    
                    Core Advantage Analysis
                    
Explosion-proof safety features                    
· Explosion-proof certification guarantee: Compliant with national standards (such as GB 3836), common explosion-proof types include:                     
 Flameproof type (Ex d): The enclosure can withstand the internal explosion pressure and prevent the spread of flames.                     
 Explosion-proof type (Ex ia): Limits the circuit energy to prevent electric sparks from igniting hazardous media.                     
· Resistance to environmental interference: Suitable for harsh working conditions such as high temperatures, vibrations, and humidity. The protection level of the enclosure is usually ≥ IP65.                    
                    
Advantages of the electrical contact function                    
·Bidirectional alarm and control: Two contact points can be set for upper and lower limits, enabling dual protection against excessive pressure/low pressure.                     
·High reliability contacts: Utilize silver alloy contacts, with low contact resistance and long service life (typically ≥ 100,000 operations).                     
· Strong signal compatibility: The contact output can be connected to PLC, DCS systems, or driven by relays and sound-light alarms.    

                Key parameters and points for model selection
                    
Measurement range and accuracy                    
·Range: The working pressure should be within the range of 1/3 to 2/3 of the full scale. Avoid prolonged overpressure (for example, if measuring a pressure of 0.6 MPa, select a range of 0 to 1 MPa).                     
·Accuracy level: For general scenarios, select level 1.6; for precise control, choose level 0.4 (such as pressure calibration in laboratories).                    
                    
Contact capacity and electrical parameters                    
·Contact capacity: It must match the load power (e.g. AC 220V/3A, DC 24V/5A). In cases of high current, a intermediate relay needs to be used.                     
·Signal type: Normally open / normally closed contacts are available. It is recommended to select based on the logic of the control system (for example, the circuit should be disconnected when the pressure is high).                    
                    
Structure and installation compatibility                    
· Shell material: 316L stainless steel is selected for corrosive environments, while cast aluminum is used in ordinary scenarios (surface anti-corrosion treatment is required).                    
·Installation method: Radial/axial mounting, flange connection, etc. It must match the interface size of the pipeline (such as M20*1.5 thread).                    
                    
                    
                    Selection Considerations
                    
Media compatibility                    
Although no isolation barrier is required, it is necessary to confirm whether the medium has any corrosive effect on the head material (such as copper components) (optional all stainless steel structure).                    
                    
Ambient temperature                    
Ambient temperature: Explosion-proof instruments are usually resistant to temperatures ranging from -20℃ to 60℃. For high-temperature applications that require continuous operation, it is necessary to select models that are resistant to high temperatures (such as those with heat dissipation design).                    
                    
Compliance certification                    
It is necessary to obtain the explosion-proof certificate and the factory inspection report. Ensure compliance with local safety regulations (such as China's Ex, EU's ATEX).