S-G-03–Specifications for the approval of type of gas metering devices–Part 18

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


Part 18: Pressure regulators

Table of contents


1.0 Scope

This part of the Specifications applies to pressure regulators intended for use in pressure factor metering (PFM).

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

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

  • 2.1 Rated operating conditions
  • 2.3 Maximum permissible errors
  • 2.6 Working pressure
  • 2.10 Orientation

3.1 Maximum permissible error

The difference between the set pressure and the outlet pressure must be such that the error in the resultant pressure factor must not exceed a MPE of ±1%. For the purpose of this Part, the error must be determined as follows:

E = [ P o P set P set + P s ] × 100 %

Where:

  • E is percent error
  • Po is the regulator outlet pressure (gauge)
  • Pset is the regulator set pressure (gauge)
  • Ps is the standard pressure

Note: Strictly speaking, the ambient atmospheric pressure should be used in place of Ps in the denominator of the above equation. However, in this case, standard pressure is used to eliminate the effect varying atmospheric pressure would have on the repeatability of tests.

4.0 Technical requirements

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

  • 3.1 Design, composition and construction
  • 3.4 Case

5.0 Marking requirements

Note: 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
    • (j) Gas temperature range for which the errors ≤ MPE
  • 4.12 Inspection number
  • 4.13 Verification marks
  • 4.14 Operating information

5.1 General

A nameplate, tag, sticker or other suitable means must be provided for the following markings and it must be ensured that these markings are accessible during PFM inspections without the requirement for specialized equipment:

  • inlet pressure range;
  • outlet pressure set point;
  • orifice size(s); and
  • spring identification.

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.

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