# ACCEPTABLE STANDARDS

**Citation:** NCUC Rule R6-21  
**Type / status:** regulation / current  
**Agency:** North Carolina Utilities Commission  
**Effective:** Not stated  
**Published:** Not stated

Unless otherwise specified by the Commission, the utility shall use the applicable provisions in the publications listed below as standards of accepted good practice. (1) The ASME Guide for Gas Piping Systems - Appendix G-K (Leakage Classification). (2) The latest edition of the American Standards A

## Document text

Unless otherwise specified by the Commission, the utility shall use the applicable provisions in the publications listed below as standards of accepted good practice.

(1) The ASME Guide for Gas Piping Systems - Appendix G-K (Leakage Classification).

(2) The latest edition of the American Standards Association pamphlet, ASA Z21.30, "Installation of Gas Appliances and Gas Piping in Buildings," or the latest edition of the National Board of Fire Underwriters publication, NFPA No. 54, "Piping, Appliances and Fittings for City Gas."

(3) The current edition of the NFPA No. 59, "The Storage and Handling of Liquefied Petroleum Gases at Utility Gas Plants."

(4) "Standard Methods of Gas Testing," Circular No. 48, National Bureau of Standards, 1961. (The applicable portions of this circular have been substantially reproduced in the American Meter Company Handbook E-4, covering the testing of positive displacement meters.)

(5) "Testing Large Capacity Rotary Gas Meters," Research Paper No. 1741, National Bureau of Standards Journal of Research, September, 1946.

(6) "Standard Method of Test for Calorific Value of Gaseous Fuels by Water- Flow Calorimeter," American Society for Testing Materials, Standard D 900-55.

(7) "Purging Principles and Practices," American Gas Association.

(NCUC Docket No. G-100, Sub 7, 5/31/67; NCUC Docket No. G-100, Sub 7, 3/20/68; NCUC Docket No. G-100, Sub 34, 10/5/77.)

## Provenance

- Official: Yes
- Source: <https://www.ncuc.gov/ncrules/Chapter06.pdf>
- Source ID: `nc-ncuc-chapter-6`
- SHA-256: `fc2430b5a73448971620c07873727590e3a25bc56e57664becead426ba9cc08c`
- Retrieved: 2026-08-20T09:05:56.011Z
- Exported: 2026-08-22T19:11:33.138Z
- Document slug: `nc-ncuc-r6-21`

### Source metadata

```json
{
  "jurisdiction": "US-NC",
  "chapter": 6,
  "rule": "R6-21",
  "category": "adjacent-gas-safety",
  "corpusScope": "bounded-ncuc-chapter-6-pipeline-and-materially-adjacent-gas-safety",
  "selectedRuleCount": 23,
  "chapterHeadingCount": 101,
  "statutoryAuthority": "N.C. Gen. Stat. § 62-50",
  "incorporatedFederalStandards": [],
  "references": [],
  "scopeCaveat": "This is a bounded Chapter 6 pipeline/gas-safety corpus, not the entire 122-page Natural Gas chapter and not a claim to all North Carolina pipeline law. It preserves complete selected rules while excluding broader tariff, billing, customer-relations, metering-administration, service-territory, accounting, expansion-funding, and economic-development rules, plus repealed and reserved provisions.",
  "applicabilityCaveat": "Applicability depends on NCUC jurisdiction under G.S. 62-50, operator and facility status, the rule-specific definition of utility, federal/state jurisdiction and preemption, Commission exemptions or orders, and incorporated federal standards. Chapter 6 also reaches interstate natural-gas companies only insofar as the Commission has safety jurisdiction; it does not establish state jurisdiction over every pipeline or customer-owned installation in North Carolina.",
  "incorporationCaveat": "R6-39 and R6-41 incorporate federal pipeline requirements and amendments, including 49 CFR Parts 191, 192, 193, 198, and 199, with stated North Carolina modifications. Other selected rules refer to privately published ASME, NFPA, ASA, AGA, NARUC, and testing standards. This connector preserves references but does not reproduce or determine the current content, licensing terms, or legal effect of incorporated material.",
  "publicationCaveat": "The source is the current agency-hosted Chapter 6 compilation retrieved on the recorded fetch date. NCUC warns on its rules index that posting can lag an order adopting or revising a rule. Publisher history dates are retained as history entries and are not represented as effective dates unless the source expressly says so.",
  "rights": "North Carolina government text and official source links are preserved for provenance. Public availability does not determine rights in agency seals, site presentation, privately authored standards, or incorporated third-party material; redistribution and downstream use require rights review.",
  "rightsReviewRequired": true,
  "region": "NC"
}
```