The DigitalFlow GF868 flare gas flow meter is ideal for flare gas applications due to its ability to track down leakage with positive material identification, reduce the cost of steam usage with proportional control and conserve energy by eliminating unnecessary flaring. The GF868 flow meter also complies with government regulations for pollution control and improves plant material balance. The GF868 meter is also ideal for the measurement of vent gas.
Advantages of the DigitalFlow GF868
The DigitalFlow GF868 flare gas meter uses a patented method for calculating the average molecular weight of hydrocarbon mixtures. This proprietary algorithm extends the range for measuring the average molecular weight, while improving accuracy and compensating for non hydrocarbon gases better than ever before possible.
Ultrasonic flow measurement is the ideal technology when it comes to flare gas applications as it is fully dependent on gas properties and will not interfere with the flow of the gas. The all-metal transducers are installed into the pipes and each act as signal generators and receivers for the ultrasonic signals. These pulses are sent both upstream and downstream through the gas and the difference between these transit times each way is calculated. The onboard flow computer is then able to calculate velocity, volumetric and mass flow rate using the advanced signal processing and correlation detection. Temperature and pressure inputs enable the meter to calculate the standard volumetric flow. Maximum accuracy can be obtained by using the dual channel version to measure the two paths at the same point. The dual channel option can also be used on two points on the same pipe or on two different pipes.
The newly developed Net Heating Value (NHV) measurement feature has also been added to Panametrics ultrasonic flare meter GF868. You can add the option of measuring the NHV of flare gas, this will help operators achieve a smokeless flame and maintain high combustion efficiency. Optimising performance of their assisted flares and limit emissions, with real time measurement and accuracy between 2-5%.
Manufactured by: Panametrics
Model: GF868 Flare Gas Flowmeter
Flare gas
Vent gas
Operation and Performance | |
Fluid Types | Flare and vent gases |
Pipe Sizes | 2 in to 120 in NB (50 mm to 3,000 mm) and larger |
Pipe Materials | All metals. Consult RS Hydro for other materials. |
Flow Accuracy (velocity) | - 1 path measurement: ±2% to 5% of reading at ±1 to 275 ft/s (±0.3 to 85 m/s) - 2-path measurement: ±1.4% to 3.5% of reading at ±1 to 275 ft/s (±0.3 to 85 m/s) |
Molecular Weight Accuracy (hydrocarbon mixtures) | MW 2 to 120 gr/gr mole/±1.8%, optimizable for other gas compositions |
Mass Flow Accuracy (hydrocarbon mixtures) | - 1-path: 3% to 7% - 2-path: 2.4% to 5% Dependent on accuracy of temperature and pressure inputs. Accuracy depends on pipe size and whether measurement is one-path or two-path. Accuracy to ±0.5% of reading may be achievable with process calibration. |
Repeatability | ±1% at 5 to 100 ft/s (15cm/s to 30 m/s) |
Range (bidirectional) | -275 to 275 ft/s (-84 to 84 m/s) |
Rangeability (overall) | 2750:1 |
Measurement Parameters | Mass flow, standard and actual volumetric flow, totalised flow, and flow velocity |
Electronics | |
Flow Measurement | Patented Correlation Transit-Time mode |
Enclosures | • Standard: Epoxy-coated aluminum weatherproof Type 4X/IP66 Class I, Division 2, Groups A, B, C & DFM and CSA • Optional: Stainless steel, fibreglass, explosion-proof, flameproof |
Dimensions | • Weight 11 lb (5 kg) • Size (h x w x d) 14.24 in x 11.4 in x 5.12 in (362 mm x 290 mm x 130 mm) |
Channels | • Standard: One channel • Optional: Two channels (for two pipes or two-path averaging) |
Display | Two independent software configurable 64 x 128 pixel backlit LCD graphic displays |
Keypad | 39-key tactile-feedback membrane |
Power Supplies | • Standard: 100 to 130 VAC, 50/60 Hz or 200 to 265 VAC, 50/60 Hz • Optional: 12 to 28 VDC, ±5% |
Power Consumption | 20W maximum |
Operating Temperature | -4°F to 131°F (-20°C to 55°C) |
Storage Temperature | -67°F to 167°F (-55°C to 75°C) |
Standard Inputs | Two isolated 0/4 to 20 mA inputs (121 Ω) with integral 24 VDC power supply |
For required temperature and pressure inputs | |
Standard Outputs | • Six 4 to 20 mA outputs, software assignable two outputs for 550 Ω maximum load • Four outputs for 1000 Ω maximum load. |
Optional inputs / outputs | There are four additional slots available for any combination of the following I/O boards: |
• Analog outputs: | Select up to three additional output boards, each with four isolated 0/4 to 20 mA outputs, 1 k Ω maximum load |
• Analog inputs: | Select up to three boards of one of the following types: - Analog input board with two isolated 4 to 20 mA inputs and 24V loop power - RTD input board with two isolated, three-wire, RTD inputs; span -148°F to 662°F (-100°C to 350°C); 100 Ω Pt |
• Totaliser/frequency outputs: | Select up to three totaliser/frequency output boards, each with four outputs per board, 10-kHz maximum. All boards allow software selectable functioning in two modes: - Totaliser mode: Pulse per defined unit of parameter (e.g., 1 pulse/ft3) - Frequency mode: Pulse frequency proportional to magnitude of parameter (e.g., 10 Hz = 1 ft3/h) |
• Alarm relays: | Select up to two boards of one of the |
Digital Interfaces | • Standard: RS232 • Optional: RS485 (multiuser) • Optional: HART® protocol • Optional: Modbus® protocol • Optional: Ethernet TCP/IP |
Site parameter Programming |
Menu-driven operator interface using keypad and “soft” function keys |
Data logging | Memory capacity (linear and/or circular type) to log more than 43,000 flow data points |
Display functions | • Graphic display shows flow in numerical or graphic format • Displays logged data and diagnostics |
European compliance | Complies with EMC Directive 89/336/ EEC, 73/23/EEC LVD (Installation Category II, Pollution Degree 2) and PED 97/23/EC for DN <25 |