CGT-02
Turbine Gas Meter
for custody transfer
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 veloci-
ty of the rotation is proportional to the gas flow rate. The rotary motion of
the turbine wheel is transferred mechanically by gear wheels, and the incor-
porated gas tight and hermetic magnetic coupling, to the index unit, mount-
ed on the top of the body, and shows the volume on the totalizer. The basic
components of the COMMON CGT series turbine gas meter are as follows:
Metrology:
The meters are manufactured in accordance with EC regulations and OIML recom-
mendations. The maximum permissible error is ±2% in the range Q+ Q, and
±1% in the range Q÷Qmax Meters with improved accuracy may be delivered on
request. Typical rangeability is 1:20. Some meters may be delivered with extended
rangeability 1:30. When meters operate at high pressure the rangeability can be
extended (depends on operating pressure).
• pressure resistant meter body (1)
• inlet flow conditioner (2)
•measuring cartridge with the turbine wheel (3)
• magnetic coupling as the transferring element between the measuring
• cartridge and the index head (4)
• index head, IP67 protection class (5)
• lubricating system (some meters may be provided with self lubricating bearings)
Typical error curve of Turbine Meters
✓ pressure rating: PN10 + PN110 & ANSI150 ÷ ANS1600
✓ nominal diameter:
DN50 up to DN400
✓ meter bodies: ductile cast iron or steel
✓ flow: 5 to 10 000 m³/h
✓ rangeability:
1:20 min at atmospheric pressure
(increased rangeability on request)
✓ upstream pipe:
minimum 2 x DN
✓ temperature range:
gas temperature -25°C to +70°C
ambient temperature -25°C to +70°C
✓ operating position:
horizontal or vertical
measurement accuracy according to
✓ EN12261 standard:
0.2Qmax÷Qmax < ±1%
Qmin + 0.2Qmax < ±2%
✓ improved accuracy on request
approvals:
. MID
• PED
• ATEX
✓ traceabilty to PTB standards
Basic metrological parameters
Pressure loss
Pressure drop during the gas flow through the meter according to EN12261 is determined for air at atmospheric conditions.
To calculate pressure drop at higher pressures, the following formula may be used:
Definitions:
Prz – pressure loss at pressure p [Pa]
pw – specific density of gas related to air
pa – base pressure (1,01325 bar)
p – gauge pressure upstream the meter
Wpd – coefficient from the diagram below
p – pressure loss [Pa] at Qrnax from the Table with CGT-02 basic parameters
Outputs:
✓ Up to 10 transmitters for DN100-400
✓ Up to 8 transmitters for DN50-80
✓ 2 off low frequency pulse sensors (LFK reed contact or LFW Wiegand)
✓ LFI – low frequency inductive pulse sensors (NAMUR)
✓ HF1, HF2 – inductive pulse sensor s in the index head (NAMUR)
✓ HF3, HF4-inductive pulse sensors over the turbine wheel (NAMUR)
✓ HF5, HF6-inductive pulse sensor over the reference wheel (NAMUR)
✓ AFK – anti-fraud reed contact
✓ Electrical outputs – Amphenol TUCHEL
✓ Index housing made of aluminium what perfectly protects index head against accidental damages
✓ Index housing may be provided with two separate sockets
✓ 2 pressure measurement taps as standard
✓ 2 temperature measurement taps (option)
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