Measurement method:
The flowmeter’s operating principle is based on the dependence of the oscillation frequency of the measured medium jet in the flowmeter’s sensitive element on volumetric flow rate of the gas flowing through it. A fluid oscillator is used as the sensitive element of the flow transducer. The partial flow rate, flowing through the sensitive element, is ensured by the flow rate former. The oscillation frequency, proportional to the flow rate, formed in the sensitive element fluid oscillator, is received by the piezoelectric transducer and converter into an electric frequency signal coming to the electronic unit of the flow transducer. In the electronic unit the electric frequency signal, delivered from the piezoelectric transducer, is converted into a digital signal which determines the gas volume flow rate in the working conditions.
Purpose:
Measuring volumetric flow rate of gas transported via pipelines in gas supply / gas distribution systems.
Field of application:
The gas flowmeters Turbo Flow of GFG-dP series are used for upgrade of gas metering sections on the basis of orifices equipped with pressure differential transducers in gas supply, chemical industry and heat-power engineering.
Specific features of flowmeter:
- High accuracy: relative measurement error not more than 1% throughout the range of operating flow rate;
- Wide dynamic range of measurements 1:100, possible extension to 1:160. The instrument can be used for summer and winter gas consumption volumes, thus a single instrument is used instead of two;
- Can be mounted on pipelines with DN from 50 to 1,400 mm;
- Absence of mandatory requirements to presence of minimum straight sections allows mounting the instrument on any pipelines;
- The possibility of operation at facilities without electric power supply;
- Universal protocol of exchange with automatic process control systems (MODBUS RTU);
- Cost saving due to the possibility of instrument installation on an existing orifice (Gas measuring system GFG-dP (with a diaphragm without a straight section);
- Absence of moving parts exposed to wear enhances instrument’s reliability and extends service life
Configuration options:
Based on components and performed functions:
- Configuration С0 – includes a flow transducer, a flow rate former;
- Configuration С1Т – includes a flow transducer, a flow rate former, temperature transducer, parameter computer;
- Configuration С1ТР – includes a flow transducer, a flow rate former, temperature transducer, pressure transducer, parameter computer;
- Configuration С1ТРП – includes a flow transducer, a flow rate former, temperature transducer, pressure transducer, parameter computer, interface for connection of external transducers;
- Configuration С2ТР – includes a flow transducer, a flow rate former, temperature transducer, pressure transducer, parameter computer, external terminal;
- Configuration С2ТРП – includes a flow transducer, a flow rate former, temperature transducer, pressure transducer, parameter computer, external terminal, interface for connection of external transducers.
Based on explosion protection:
- 0 Ex ia IIC T4 Ga (0 Ex ia IIC T6 Ga);
- 1 Ex d [ia Ga] IIC T4 Gb (1 Ex d [ia Ga] IIC T6 Gb).
Technical specifications:
| Characteristic |
Value |
| Range of gas flow rate measurements, m3/hour |
from 0.016 to 280,000 |
| Dynamic range Qmin/Qmax |
1:100 (special configuration 1:160) |
| Nominal diameter, mm |
from 10 to 1,400 |
Limits of relative error during measurement of volumetric gas flow rate in working conditions, %, in the range:
Qmin < Q < 0.01Qmax:
0.01Qmax ≤ Q ≤ Qmax: |
± 1,5
± 1,0 |
| Gas overpressure range, MPa |
from 0 to 20 |
| Upper limits of overpressure measurements (ULM), MPa |
from 0,0025 to 20 |
| Upper limits of absolute pressure measurements (ULM), MPa |
from 0.1 to 20 |
| Limits of permissible relative error during pressure measurement, % |
± 0,25 |
| Working range of pressure measurements, % of ULM |
from 33 to 100 |
| Gas temperature range, °С |
from – 50 to + 70 |
| Limits of permissible absolute error during temperature measurement, °С |
± (0.15 + 0.002|t|),
where t – measured temperature |
| Limits of permissible relative error during calculation of gas mass flow rate and weight, volume, volumetric flow rate and volume of gas reduced to standard conditions, % |
± 0,02 |
| Limits of permissible reduced error during conversion of measured gas flow rate into output current signal (from 4 to 20 mA), % |
± 0,1 |
| Limits of permissible relative error during conversion of gas flow rate into output frequency signal, % |
± 0,1 |
| Limits of permissible reduced error during direct current measurement (from 4 to 20 mA), % |
± 0,1 |
Performance specification:
| Characteristic |
Value |
| Digital wired interfaces |
HART, MODBUS RTU |
| Digital wireless interfaces |
GSM, GPRS, Bluetooth, IrDA (ИК-порт) |
| Power supply parameters, V: |
- from built-in battery 7.2;
- from external power unit from 12 to 18;
- from ~220 mains ± 22
|
| Power consumption, W, no more than |
15,0 |
Operating conditions:
- ambient air temperature, °С
- relative air humidity, %
|
|
| Average mean time between failures, hours, at least |
60000 |
