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ANSI Z21.94a-2007/CSA 6.31a-2007 (R2016): Safety Requirements for Connectors for Outdoor Unvented Cooking Appliances
A Technical Guide to the Joint ANSI/CSA Standard for Gas Connectors in Outdoor Cooking Equipment
Scope and Overview
The joint standard ANSI Z21.94a-2007 · CSA 6.31a-2007 (R2016) specifies the safety, construction, and performance requirements for connectors intended to connect outdoor unvented cooking appliances (e.g., gas grills, portable stoves, and backyard cookers) to a fuel gas supply. The standard covers connectors for both natural gas and propane (LP-gas) systems operating at pressures typically up to ½ psi (3.5 kPa).
This standard applies to flexible hose connectors, semi-rigid connectors, and quick-disconnect devices that are part of the connector assembly. It does not apply to permanently installed piping or connectors used for indoor appliances—those are covered by separate Z21/CSA standards. The 2016 reaffirmation confirms that the technical provisions remain current without modification.
Tip: Outdoor cooking appliance connectors must be distinguished from indoor connectors (e.g., Z21.69/CSA 6.16). Always verify the intended use environment when selecting a certified connector.
Technical Requirements
Construction and Materials
Connectors must be fabricated from materials resistant to corrosion and outdoor weathering. Hose assemblies shall use an outer cover rated for UV exposure and extreme temperatures (−40°F to 140°F / −40°C to 60°C). All metallic components must be corrosion-resistant steel or brass. The connector must incorporate a means of strain relief at each end fitting.
Dimensional and Design Constraints
- Length: Connector assemblies shall not exceed 6 ft (1.8 m) unless otherwise approved for residential outdoor use.
- Minimum bend radius: The connector shall have a bend radius no greater than 4 times the nominal hose diameter to prevent kinking.
- End connections: All fittings must comply with ANSI B1.20.1 (NPT taper threads) or approved flare-type equivalents.
Performance Testing
Each connector design shall pass a series of qualification tests. The following table summarizes key test conditions and acceptance criteria:
| Test | Condition | Requirement |
|---|---|---|
| Leakage (air or inert gas) | 15 psig (103 kPa) for 1 minute | No detectable leakage pressure drop of ≤ 0.02 psig |
| Burst (hydrostatic) | 4× rated working pressure (min. 200 psig) | No rupture or permanent deformation |
| Flow capacity | 3.5 in. WC (0.87 kPa) pressure drop at rated gas flow | Must equal or exceed appliance Btu/hr rating |
| Flexing endurance | 20,000 cycles at ±135° bend, 10 cycles/min | No cracks, leaks, or loss of metal continuity |
| Temperature resistance | −40°F to 140°F (−40°C to 60°C) with gas pressure | No blockage or structural failure after 24 h |
| UV weathering (hose only) | 1,000 h per ASTM G155 | No cracking, fading, or surface degradation |
Marking and Instructions
Every connector must be permanently marked with the manufacturer’s name or trademark, model designation, length, fuel gas type (Natural or LP), date code, and the certification mark of a nationally recognized testing laboratory (e.g., CSA, UL, ETL). Installation instructions shall be supplied with each unit and include warnings regarding proper gas type, minimum clearance from combustible surfaces, and the requirement to use only with outdoor unvented appliances.
Warning: A connector certified under this standard shall not be used for indoor applications or for appliances that require a vent (e.g., ovens, ranges). Doing so may create a carbon monoxide hazard.
Implementation Highlights for Manufacturers and Installers
Design for outdoor reliability. Connector assemblies should incorporate a protective jacket or aramid braid to resist UV and rodent damage. Quick-disconnect devices (if fitted) must include a positive shutoff when disconnected, as per Annex A of the standard.
On-site installation checks. Installers should confirm the connector length is not excessive (maximum 6 ft) and that no portion of the hose is in contact with hot surfaces of the appliance. The connector must be routed to avoid sharp edges and kinking.
Best Practice: Use a certified gas flex connector that meets Z21.94a/CSA 6.31a for new installations and replacements. Always replace a connector that shows evidence of cracking, abrasion, or if it has been in service for more than 10 years.
Comparison with other standards. Unlike Z21.69 (indoor connectors), this standard requires more stringent UV and low-temperature tests. The flow capacity requirement is based on the average outdoor cooking appliance’s Btu demand (typically 20,000–150,000 Btu/hr).
Compliance and Certification Notes
Manufacturers seeking certification to ANSI Z21.94a-2007/CSA 6.31a-2007 (R2016) must submit samples to a recognized third-party laboratory (e.g., CSA Group, Intertek). The certification program includes:
- Initial design review and construction evaluation.
- Type testing of all performance parameters listed in the standard.
- Manufacturing facility inspection and quality management system assessment.
- Annual follow‑up testing and periodic audit of production samples (listing maintenance).
The standard incorporates by reference several ASTM, ASME, and ANSI companion standards; a complete list is found in the normative references section of the document. Changes introduced in the a suffix addenda clarified hose marking requirements and added acceptance criteria for the quick-disconnect pull‑out test.
Critical: Using a connector that does not bear a valid certification mark may void manufacturer warranties and may not meet local building codes. Always verify the listing mark for compliance.
Frequently Asked Questions
Q: What types of connectors are covered under ANSI Z21.94a-2007/CSA 6.31a-2007?
A: The standard covers flexible hose connectors, semi-rigid metallic connectors, and integral quick‑disconnect devices intended for outdoor unvented cooking appliances such as gas grills, turkey fryers, and portable camp stoves. It does not cover connectors for fixed piping, indoor appliances, or vented equipment.
A: The standard covers flexible hose connectors, semi-rigid metallic connectors, and integral quick‑disconnect devices intended for outdoor unvented cooking appliances such as gas grills, turkey fryers, and portable camp stoves. It does not cover connectors for fixed piping, indoor appliances, or vented equipment.
Q: How does this standard differ from ANSI Z21.69/CSA 6.16?
A: Z21.69/CSA 6.16 applies to connectors for indoor gas cooking appliances, while Z21.94a/CSA 6.31a is specifically for outdoor unvented cooking appliances. The outdoor standard includes additional UV resistance testing, more stringent temperature extremes, and requirements for weather‑resistant materials.
A: Z21.69/CSA 6.16 applies to connectors for indoor gas cooking appliances, while Z21.94a/CSA 6.31a is specifically for outdoor unvented cooking appliances. The outdoor standard includes additional UV resistance testing, more stringent temperature extremes, and requirements for weather‑resistant materials.
Q: Do quick‑disconnect devices included with the connector need separate certification?
A: Yes, any quick‑disconnect (QD) incorporated into the connector assembly must comply with the performance requirements of Annex A of this standard. The QD must be tested for leakage before and after disconnection and must provide a positive shutoff.
A: Yes, any quick‑disconnect (QD) incorporated into the connector assembly must comply with the performance requirements of Annex A of this standard. The QD must be tested for leakage before and after disconnection and must provide a positive shutoff.
Q: Is compliance with this standard mandatory under U.S. or Canadian building codes?
A: Many local and state codes in the U.S. adopt ANSI Z21 series standards by reference. In Canada, the standard is referenced in the Natural Gas and Propane Installation Code (CSA B149.1). Therefore, compliance is generally required for legal installation. It is advisable to check with the local authority having jurisdiction (AHJ).
A: Many local and state codes in the U.S. adopt ANSI Z21 series standards by reference. In Canada, the standard is referenced in the Natural Gas and Propane Installation Code (CSA B149.1). Therefore, compliance is generally required for legal installation. It is advisable to check with the local authority having jurisdiction (AHJ).
Technical article published in 2026. The above information reflects the requirements of ANSI Z21.94a-2007 · CSA 6.31a-2007 (R2016) as reaffirmed.