1、 Installation specifications
1. Flow direction and straight pipe section requirements
Ensure that the gas flow direction is consistent with the arrow mark on the flowmeter during installation to avoid errors caused by reverse measurement.
Length of straight pipe section: At least 10 times the diameter of the pipe (10D) should be reserved upstream of the flowmeter, and at least 5 times the diameter of the pipe (5D) should be reserved downstream to stabilize the flow field.
2. Installation position and posture
Prohibit low installation: Avoid installing at the lowest point of the pipeline to prevent water accumulation and impurity accumulation from damaging the sensor.
Horizontal calibration: Regardless of whether installed vertically or horizontally, the flowmeter body must be kept in a horizontal state.
Vibration avoidance: Keep away from strong mechanical vibration sources, and the plug-in probe should be firmly fixed to the pipeline.
3. Environment and Safety Protection
Explosion proof environment: Welding operations are prohibited in explosive environments.
Outdoor protection: Sunshade and rain cover should be installed for outdoor installation.
Electromagnetic interference: Keep away from strong electric and magnetic field equipment (such as large motors).
2、 Media and operating conditions limitations
1. Prohibited gas types
Acetylene gas: prone to decomposition reaction, measurement is prohibited.
Moisture/Steam: Moisture may cause measurement distortion or sensor damage.
2. Flow rate and accuracy range
Applicable flow rate: Typical range is 0.5~60 m/s. If it exceeds the upper limit, other flow meters need to be selected.
Accuracy limitation: The conventional accuracy is ± 1% FS~± 2% FS, and a Coriolis flowmeter is required for high-precision scenarios.
3. Boundary of operating condition parameters
Temperature/Humidity: Environmental temperature ≤ 80 ℃, humidity ≤ 85%, exceeding the limit requires protective measures.
Pressure upper limit: It is prohibited to exceed the maximum working pressure calibrated on the nameplate.
3、 Key points of operation and maintenance
1. Start stop and debugging
Pressure operation: The installation/removal of the plug-in flowmeter under pressure requires the use of an online plug-in structure to avoid the probe flying out.
Zero point calibration: Zero point adjustment should be performed after initial use or long-term disuse.
2. Periodic maintenance
Cleaning cycle: Regularly remove dust and pipeline impurities from the sensor surface, and do not use chemical solvents for wiping.
Sealing inspection: Focus on testing the sealing of flanges/insertion ports to prevent leaks (especially harmful gases).
3. Troubleshooting
Exception handling: When displaying an exception, priority should be given to checking the stability of the power supply, the fullness of the pipeline, and the integrity of the signal line. Blind disassembly is prohibited.
Static protection: Independent grounding wire, prohibited from sharing grounding with strong electrical systems.
4、 Special scenario measures
1. Uninterrupted gas supply: Key processes require the installation of bypass pipelines to prevent accidents caused by unexpected gas outages.
2. Corrosive gas: Confirm the corrosion resistance of the instrument material (such as aluminum alloy), otherwise customized anti-corrosion coating is required.
3. High precision requirement: Regularly calibrate the specific heat capacity parameters according to the actual composition of the gas to ensure measurement consistency.
Key reminder: Acetylene and saturated steam are absolutely prohibited media; The lower limit sensitivity of the instrument needs to be verified for low flow rates (<0.5m/s). Strictly follow the Lock Tag Out (LOTO) safety procedure during maintenance.