Category: Gas
Issue date:
Effective date:
Revision number: 3
Supersedes: S-G-03 (rev. 2)
Part 10: Mechanical gas metering devices incorporating volume conversion functions
Table of contents
- 1.0 Scope
- 2.0 Unit requirements
- 3.0 Metrological requirements
- 4.0 Technical requirements
- 5.0 Marking requirements
- 6.0 Sealing requirements
- 7.0 Administrative requirements
- 8.0 Performance test requirements
1.0 Scope
This part of the Specifications applies to mechanical gas metering devices incorporating volume conversion functions. Such devices may be:
- incorporated entirely within a gas meter (i.e. integral);
- of a modular nature; or
- intended for use as auxiliary attachment (i.e. stand-alone device).
Note: The requirements of this part do not apply to internal temperature-compensated diaphragm meters.
Four types of volume conversion are dealt within this part:
- temperature only;
- pressure only;
- pressure and temperature;
- pressure, temperature and compressibility.
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
- 2.3 Maximum permissible error
According to the characteristics of the device, the following requirements may also apply:
- 2.6 Working pressure
- 2.7 Temperature
3.1 Maximum permissible errors
The difference between the error of the converted registration and the unconverted registration must not exceed the maximum permissible errors (MPE) specified in Table 1 below.
Volume conversion as a function of: | Test conditions | MPE |
---|---|---|
Pressure or temperature | Reference | ± 0.8% |
"Other than reference" | ± 1.3% | |
Pressure and temperature | Reference | ± 1.0% |
"Other than reference" | ± 1.5% | |
Pressure, temperature and compressibility | Reference | ± 1.5% |
"Other than reference" | ± 2.0% |
4.0 Technical requirements
Notes: The following requirements of Part 1, section 3.0 apply:
- 3.1 Design, composition and construction
- 3.4 Case
- 3.7 Indication
- 3.12 Registration
According to the characteristics of the device, the following requirements may also apply:
- 3.2 Minimum temperature range
- 3.3 Automatic volume conversion
- 3.11 Compressibility factor
4.1 Level indicator
Where the operation of a device depends on it being level, it must be equipped with a suitable level indicator.
4.2 Frequency of integration
Intermittent type integrators must integrate at least once for every ten revolutions of the input shaft.
5.0 Marking requirements
Note: The requirement of Part 1, subsection 4.1 applies, as well as the following requirements where the information must be marked on the device or the host meter, where applicable:
- 4.2
- (a) Departmental approval number
- (b) Manufacturer's name or registered trademark (Footnote *)
- (c) Model or type designation (Footnote *)
- (d) Serial number
- (e) Ambient temperature range, where less than -30 °C to 40 °C
- (f) Pmin (where applicable) and Pmax (Footnote *)
- (j) Gas temperature range for which the errors ≤ MPE (Footnote *)
- 4.3 Bar codes or quick response codes
- 4.4 Temperature converted volume
- 4.5 Pressure converted volume
- 4.12 Inspection number
- 4.13 Verification marks
- 4.14 Operating information
5.1 General
- The following information must be marked on the device or the host meter, where applicable:
- Fixed parameters for compressibility factor (e.g. gas relative density, N2 and CO2 content);
- Volume per revolution of input drive.
- Devices intended for use as auxiliary attachment must also be marked with the following information:
- Maximum speed of rotation of the input drive;
- Direction of rotation of the input drive;
- Input volume per revolution of the input drive.
6.0 Sealing requirements
Note: The requirement of Part 1, subsection 5.1 applies.
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.