CGT-02 Turbine Gas Meter
||PN16 to PN110,
ANSI150 to ANSI600
|other rates on request|
|Nominal diameter:||DN50 up to DN300 standard range||other on request|
|Meter bodies:||cast iron or carbon steel
||details in table 4|
|Flow:||6.5 to 6 500 m3/h||other on request|
||1:20 minimum at atmospheric pressure
||Some smaller size meters have reduced ranges.|
||minimum 2 x DN; meters meet the requirements of the OIML R32 89 Annex A|
||gas temperature -20°C to +60°C
ambient temperature -25°C to +70°C
|Allowed medias:||see table 2|
|Operating position:||horizontal or vertical|
||EU requirements and better
guaranteed at least:
0.2 Qmax – Qmax < ± 1%
Qmin – 0.2 Qmax < ± 2%
Figure 1. Measurement error typical curve at low pressure (average 1 bara) - green curve and at high pressure (over 5 bara) - blue curve
|LF Pulse rate
Table 2: Physical properties of most popular gases that may be measured with the CGT turbine gas meters - density at 101,325 kPa and at 20°C
|Gas||Chemical symbol (formula)||Density ρ [kg/m3]||Density related
|Gas meter execution|
|Carbon dioxide||CO2||1,84||1,53||standard IIB|
|Carbon monoxide||CO||1,16||0,97||standard IIB|
|Natural gas||-||~0,75||~0,63||standard IIB|
PRESSURE AND TEMPERATURE OUTPUTS
The operating pressure (reference pressure) can be taken from the pressure taps, marked pr, located on both sides of the meter body. The meters DN100 and larger can be optionally equipped with two temperature taps for the measurement of the gas temperature.
The mechanical index unit indicates the actual volume of the measured gas at operating temperature and operating pressure. It can be rotated axially by 350° in order to facilitate the readings and enable easier connection of pulse sensor plugs. The index unit is provided with one low frequency LFK reed contact pulse transmitter, as a standard. On request the index may be equipped with:
- LFI inductive pulse sensor (NAMUR)
- HF inductive pulse sensor (NAMUR)
The CGT turbine gas meters may be provided with up to 10 pulse sensors for DN100 – DN300 and up to 8 pulse sensors for DN50 – DN80
- LFK – low frequency reed contact pulse sensor LFK1, LFK2
- LFI – low frequency inductive pulse sensor LFI1, LFI2
- HF – inductive pulse sensor in the index unit HF1, HF2
- HF – inductive pulse sensor over the turbine wheel HF3, HF4
- HF – inductive pulse sensor over the reference wheel HF5, HF6
- AFK – anti-fraud reed contact AFK
The turbine wheel, as a standard, is made of aluminium. This allows to provide each CGT turbine gas meters with HF inductive pulse sensors. There are no extra costs due to the replacement of the turbine wheel.
DIMENSIONS AND WEIGHTS
* size E is valid for meters PN16, PN20 and ANSI 150, size F is valid for meters PN50, PN64, PN110, ANSI300 and ANSI600
INSTALLATION AND OPERATION RECOMMENDATIONS
- Meters should be shipped in their original package to the place of installation.
- Meters have to be handled with care and protected against falls, direct infl uence of rain, snow or high humidity.
- The measured gas should be clean, dry and free from solid impurities. It is recommended that the upstream pipe installation is to be equipped with a filter (10 micron).
- Prior to putting into operation in new installations, it is recommended to install a temporary cone sieve.
- Prior to installation the upstream and downstream pipe fl anges should be aligned properly.
- Flange gaskets are to be installed so as not to disturb the gas flow.
- The gas flow should be in accordance with the arrow placed on the meter body.
- The piping should be executed so as to avoid unnecessary stresses acting on the meter.
- When used outdoors the meter should be protected against direct weather infl uence.
- When starting the gas flow through the installation, the valves should be opened slowly to ensure a gradual increase of pressure.
ATTENTION! If valves are opened abruptly or pressure increase takes place in a short time it may happen that the measurement cartridge or the turbine wheel get damaged.
ALWAYS REMEMBER TO START UP THE METERS IN A PROPER WAY!
COMMON S.A. has continuing program of product research and development. Technical specifications and construction may change due to improvements. This publication serves as general information only, and all specifications are subject to confirmation by COMMON S.A.
CGT-02 Turbine Gas Meter
CGT series turbine gas meters are flow meters designed to measure quantity of gases. The meters are mainly used for gas flow ranges from 6.5 up to 6500 m3/h. The CGT series gas meters are applied in measurement systems where high accuracy is required:
- transportation of natural gas
- primary and secondary measurements
- control metering of the natural gas and non aggressive technical gases in industry
- flow measurement for technical purposes
The meters may be applied for measurements of aggressive gases. Any application of that kind should be individually proved and agreed between the client and COMMON S.A.
The turbine gas meter measures the quantity of gas basing on the flow principle. The gas flows through an integrated flow conditioner, which distributes the flow proportionally in the annular slot and guides it to the turbine wheel. The wheel is driven by the gas flow, and the angular velocity of the rotation is proportional to the gas flow rate. The energy consumption, perceived as pressure loss, is reduced to absolute feasible minimum due to the application of the flow conditioner, highest precision ball barings, most accurate tolerances of all measuring parts and their proper alignement. The rotary motion of the turbine wheel is transferred mechanically by gear wheels, and the incorporated gas tight and hermetic magnetic coupling, to the index unit, which is mounted on the top of the body, and shows the operating volume on the totalizer.
The basic components of the COMMON CGT series turbine gas meter are as follows:
- pressure resistant meter body
- inlet flow conditioner
- measuring cartridge with the turbine wheel
- magnetic coupling as the transferring element between measuring cartridge and the index
- lubricating system (some meters are provided with self lubricating bearings)