S-G-03–Specifications for the approval of type of gas metering devices–Part 4

Category: Gas
Issue date:
Effective date:
Revision number: 3
Supersedes: S-G-03 (rev. 2)


Part 4: Turbine meters

Table of contents


1.0 Scope

This part of the Specifications applies to axial flow turbine type gas meters.

2.0 Unit requirements

Note: The following requirements of Part 1, section 1.0 apply:

  • 1.1 Use of units
  • 1.2 Metric units of measure

3.0 Metrological requirements

Notes: The following requirements of Part 1, section 2.0 apply:

  • 2.1 Rated operating conditions
  • 2.2 Flow rate characteristics
  • 2.3 Maximum permissible errors
  • 2.4 Weighted mean error
  • 2.5 Repeatability
  • 2.6 Working pressure
  • 2.7 Temperature
  • 2.8 Durability
  • 2.9 Vibrations and shocks
  • 2.10 Orientation
  • 2.11 Flow direction

According to the characteristics of the meter, the following requirements may also apply:

  • 2.13 Drive shaft (torque)
  • 2.14 Different gases
  • 2.15 Influences from ancillary devices

3.1 Maximum permissible errors

The error of the unconverted volume registration must not exceed the MPE indicated below in Table 1.

Part 4, Table 1: Turbine meter maximum permissible errors
Test conditions Meter operating pressure type Flow rate (Q) MPE
Reference or "other than reference" Meter intended for low operating pressure (i.e. < 400 kPa [≈50 psig]) QminQQt (where Qt ≤ 0.2 Qmax) ± 1.5%
Qt ˂ QQmax (where Qt ≤ 0.2 Qmax) ± 1.0%

Meter intended for:

  • medium operating pressure (i.e. from 400 to 5000 kPa [≈50 to ≈720 psig])

or

  • high operating pressure (i.e. > 5000 kPa [≈720 psig])
QminQQmax ± 1.0%

3.2 Effect of swirl

Where a swirl exists at the inlet of the meter, the error of the unconverted volume accumulation must not exceed ±1%.

Note: Meters not meeting the requirement in the two recommended configurations judged most likely to produce inaccurate measurement will not be considered for approval of type.

3.3 Measuring cartridge interchangeability

The fault due to measuring cartridge interchangeability must not be more than one third of the MPE applicable during evaluation, while the error must in no case exceed the MPE for that range.

4.0 Technical requirements

Notes: The following requirements of Part 1, section 3.0 apply:

  • 3.1 Design, composition and construction
  • 3.4 Case
  • 3.5 Zero flow
  • 3.6 Flow direction
  • 3.7 Indication
  • 3.12 Registration

According to the characteristics of the meter, the following requirements may also apply:

  • 3.2 Minimum temperature range
  • 3.3 Automatic volume conversion
  • 3.8 Output

5.0 Marking requirements

Notes: The following requirements of Part 1, section 4.0 apply:

  • 4.1 Permanency and legibility
  • 4.2
    • (a) Departmental approval number
    • (b) Manufacturer's name or registered trademark
    • (c) Model or type designation
    • (d) Serial number
    • (e) Ambient temperature range, where less than -30 °C to 40 °C
    • (f) Pmin (where applicable) and Pmax
    • (g) Qmax
    • (h) Qmin
    • (i) Qt
    • (j) Gas temperature range for which the errors ≤ MPE
  • 4.12 Inspection number
  • 4.13 Verification marks

According to the characteristics of the meter, the following requirements may also apply:

  • 4.3 Bar codes or quick response codes
  • 4.4 Temperature converted volume
  • 4.5 Pressure converted volume
  • 4.6 Unidirectional flow measurement
  • 4.7 Bidirectional flow measurement
  • 4.8 Output drive shaft
  • 4.14 Operating information

5.1 K factors and/or rotor factors

The K factors and/or rotor factors must be marked on the nameplate, where applicable.

5.2 Interchangeable cartridges

Where a meter is designed for operation with interchangeable cartridges, the markings required in Part 1, 4.2 (a to f), and subsection 4.6 must appear on the meter case and the interchangeable cartridge.

5.3 Change gears

Where change gears are provided, the number of teeth must be permanently marked on each of the change gears in such a location as to be legible with the change gears in place.

6.0 Sealing requirements

Note: The requirements of Part 1, section 5.0 apply, except subsection 5.2.

7.0 Administrative requirements

Note: The requirements of Part 1, section 6.0 apply.

8.0 Performance test requirements

Note: Test conditions and performance tests can be obtained by contacting MC.

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