Key Factors to Consider for Selection
1. Medium Characteristics
- Fluid Type: Clearly identify whether it is gas, liquid, or steam. Different types of fluids have varying adaptabilities to flow meters. For example, Verabar and Delta Bar are more accurate in measuring gases and steam. For liquids, their viscosity and corrosiveness need to be considered. For low-viscosity liquids (≤10 cP), Verabar can be selected; for corrosive liquids, Delta Bar can better adapt due to its special material and structure.
- Temperature and Pressure: Understand the operating temperature and pressure range of the fluid. If the temperature is as high as 650℃ and the pressure is ≤32MPa, the enhanced Pitot Bar can meet the requirements; for extreme temperatures ranging from -200℃ to 1240℃ and high pressures up to 68MPa, Delta Bar is a suitable choice.
2. Accuracy Requirements
If extremely high accuracy is required, such as in trade settlement scenarios, Annubar has high accuracy under suitable working conditions but comes with high maintenance costs. If the accuracy requirement is around ±5% - 10% and cost-effectiveness is pursued, in low-flow rate scenarios, the enhanced Pitot Bar combined with AI compensation can meet the needs.
3. Turndown Ratio Requirements
When the flow range fluctuates greatly and a larger turndown ratio is needed, Delta Bar's 30:1 turndown ratio and the enhanced Pitot Bar's 50:1 turndown ratio have more advantages. For situations where the flow range is relatively stable and the turndown ratio requirement is not high, such as 5:1 or 10:1, T-type Bar and Verabar can also meet the usage needs.
4. Pipeline Conditions
- Pipe Diameter: Large-diameter pipelines (above DN300) are the advantageous field of bar-type flow meters, and different types are applicable to different pipe diameters. For example, Verabar is applicable to pipe diameters of DN38 - 9000mm; for ultra-large diameters (above DN9000mm), Delta Bar has corresponding models (such as H150 type).
- Pipeline Shape: Some bar-type flow meters support circular, square, or rectangular pipelines. For example, Verabar supports circular and square pipes; Annubar is suitable for square/rectangular pipelines.
5. Convenience of Installation and Maintenance
- Installation Space and Method: Some models support online plugging, such as Delta Bar's H350 type, which is suitable for non-stop maintenance scenarios. For situations with limited installation space, models with a compact structure need to be selected.
- Maintenance Frequency and Difficulty: Annubar requires regular cleaning of pressure taps, with moderate maintenance difficulty; the enhanced Pitot Bar has a higher maintenance frequency, requiring cleaning of pressure taps every 6 months; Verabar has an excellent anti-clogging design, making maintenance relatively simple.
6. Cost Budget
The price of bar-type flow meters varies depending on the type and pipe diameter. Taking DN800 as an example, the price of the enhanced Pitot Bar is about 40,000 - 80,000 yuan, with outstanding cost-effectiveness; Annubar is about 120,000 - 180,000 yuan, with a relatively high price. When selecting, it is necessary to combine the enterprise's budget, comprehensively consider performance and price, and choose the most cost-effective product.
Selection Suggestions for Different Application Scenarios
1. Ultra-Low Flow Rate Scenarios (<0.6m/s)
- Preferred Option: Multi-channel ultrasonic flow meters can achieve an accuracy of ±3% - 5%, but the cost is high, with DN800 costing about 150,000 - 250,000 yuan.
- Alternative Option: Enhanced Pitot Bar + AI compensation, with an error of ±5% - 10%, which needs to be combined with a high-precision transmitter (such as Rosemount 3051S).
2. Conventional Low-Pressure Steam (0.6 - 10m/s)
- Cost-Effective Choice: Delta Bar has balanced overall performance; the enhanced Pitot Bar can save 20% - 30% of the cost.
- Trade Settlement Scenarios: Annubar meets high accuracy requirements but has high maintenance costs.
3. High Vibration / Dirty Media
- Anti-Vibration Design: T-type Bar has high mechanical strength and is suitable for high-vibration environments; V-cone flow meters have strong anti-dirty capabilities but with large pressure loss.
- Anti-Clogging Optimization: Verabar's bullet-shaped anti-clogging design and Delta Bar's self-draining design can effectively deal with dirty media and reduce the risk of clogging.
Technical Development Trends of Bar Type Flow Meters
1. Intelligent Upgrading
Integrate edge computing chips (such as STM32H7) to realize real-time filtering and dynamic compensation, reduce dependence on DCS systems, and improve the real-time performance and accuracy of measurement.
2. Multi-Sensor Fusion
Combine thermal mass flow meters or humidity sensors to improve the measurement accuracy of complex media (such as two-phase flow) and meet the measurement needs of more special working conditions.
3. Material Innovation
Adopt new materials such as ceramic coatings or Hastelloy to enhance the corrosion resistance and wear resistance of probes in harsh media such as corrosive and high-wear environments, and extend the service life.
4. Standardized Protocols
Promote the popularization of communication protocols such as HART and FF to facilitate remote diagnosis and parameter adjustment, and improve the convenience and intelligence level of equipment management.
The selection of bar-type flow meters is a process that comprehensively considers various factors. Enterprises need to conduct in-depth analysis of their own process requirements, medium characteristics, pipeline conditions, etc., combine the characteristics and parameters of different types of bar-type flow meters, balance factors such as accuracy, turndown ratio, installation and maintenance, and cost, to select the most suitable flow meter, ensure accurate and stable flow measurement, and provide strong support for the efficient operation of industrial production.
