Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
ANSI Z21.84-2017 · CSA 3.4-2017: Manually Operated Gas Valves for Appliances, Connector Valves, and Hose End Valves
Safety, Design, and Performance Requirements for Gas Valves in Residential and Commercial Applications
Scope of ANSI Z21.84-2017
ANSI Z21.84-2017 (also designated as CSA 3.4-2017) specifies construction, performance, and safety requirements for manually operated gas valves used in appliances, appliance connector valves, and hose end valves. These valves are intended for use with natural gas, manufactured gas, mixed gas, liquefied petroleum gases (LP-gas), and LP-gas-air mixtures at pressures up to ½ psig (3.5 kPa). The standard covers:
- Valves with inlet and outlet connections up to and including 2 NPT;
- Valves operated by a hand wheel, knob, lever, or other manual means;
- Integral shutoff valves in appliance connector assemblies;
- Hose end valves for outdoor appliances (e.g., grills, patio heaters).
The standard is harmonized between the American National Standards Institute (ANSI) and the Canadian Standards Association (CSA), enabling manufacturers to certify a single valve design for both U.S. and Canadian markets. It supersedes earlier editions (e.g., Z21.84-2012) and includes updated requirements for leakage, cycling endurance, and marking.
Tip: Although the standard number refers to 2017, many certification bodies still accept this edition, and it remains the baseline for most North American gas valve approvals. Manufacturers should always verify current adoption dates with local authorities.
Key Technical Requirements and Design Specifications
General Construction
Valves must be fabricated from corrosion-resistant materials such as brass, stainless steel, or suitable engineered polymers. Bodies and operating stems must withstand a 1.5 × rated pressure hydrostatic test without deformation or leakage. All external parts exposed to user contact must have smooth edges and be free of burrs.
Leakage Performance
The standard establishes maximum allowable leakage rates under both low and high pressure conditions. Leakage is measured at the valve seat and along the stem or shaft seal. Tests are conducted with air or inert gas at ambient temperature.
| Valve Class | Test Pressure (psi) | Max Leakage Seat (cm³/h) | Max Leakage Stem (cm³/h) |
|---|---|---|---|
| All valves (inlet ≤ ½ NPT) | 5 ± 0.5 | 20 | 10 |
| All valves (inlet > ½ NPT to 2 NPT) | 5 ± 0.5 | 50 | 25 |
| Hose end valves | 10 ± 0.5 | 15 | 5 |
Leakage rates are measured under static conditions after the valve has been cycled 10 times. The standard also requires a 15-second bubble test for each valve during production.
Cycling Endurance (Durability)
Valves must demonstrate reliable operation through 6,000 full open/close cycles at rated pressure, followed by 6,000 additional cycles at 150 % of rated pressure (minimum 7.5 psi for nominal ½ psig systems). After cycling, leakage must remain within the limits above and the operating torque must not exceed 50 in·lbf (5.65 N·m).
Temperature Limits
Valves intended for outdoor appliances must operate between –20 °F and 140 °F (–29 °C to 60 °C). Indoor valves are tested at ambient (50 °F to 100 °F). No functional degradation or leakage is permitted after 4-hour exposure to the temperature extremes.
Marking and Instructions
Each valve must be permanently marked with:
- Manufacturer’s name or trademark;
- Model or part number;
- Gas type designation (e.g., “NAT”, “LP”, or “NAT/LP”);
- Maximum inlet pressure rating;
- Year of manufacture or date code;
- Interconnection symbol if used with a quick‑disconnect.
Warning: Valves that are not clearly marked for both gas type and pressure rating cannot be certified under this standard. Field‑applied labels are not acceptable; markings must be permanent, such as stamping or etching.
Implementation Highlights for Manufacturers
Designers and manufacturers integrating ANSI Z21.84‑2017 into production should pay attention to the following practical aspects:
- Material selection: Brass alloys (C36000, C37700) are common for bodies, but stem seals require elastomers resistant to fuel gas swelling (e.g., FKM, HNBR). NBR (Buna‑N) may be used only if temperature range is limited.
- Torque consistency: The standard requires a smooth, progressive closing feel. Detent mechanisms or over‑center springs can help achieve consistent shut‑off force.
- Production testing: 100 % air pressure decay or bubble testing is mandatory. Automated leak test stations should be calibrated with traceable leak standards every 6 months.
- Quality management: While not part of the standard, compliance is most efficiently maintained through an ISO 9001 or equivalent system with periodic third‑party audits.
Good practice: Many certification bodies (e.g., CSA, UL, ITS) offer pre‑compliance reviews that can identify design weaknesses before formal testing, reducing time to market.
Compliance and Certification Notes
To legally market a valve as ANSI Z21.84 compliant in the U.S. and Canada, manufacturers must obtain certification from an accredited third‑party organization. The certification process includes:
- Documentation review – drawings, material certifications, and instruction manuals.
- Type testing – full suite of leakage, hydrostatic, cycling, torque, and temperature tests.
- Factory inspection – initial and unannounced follow‑up audits to verify production controls.
- Annual re‑verification – periodic testing of samples to confirm ongoing compliance.
The standard does not require a specific design life, but valves that pass the 6,000‑cycle test are considered suitable for typical residential use (about 10–15 years). Any design change affecting materials, dimensions, or sealing surfaces requires re‑qualification.
Important: Self‑declaration or supplier’s declaration of conformity (SDoC) is not accepted for ANSI Z21.84‑2017. Only products bearing the mark of an OSHA‑recognized NRTL (e.g., CSA, UL, FM) or an SCC‑accredited certification body satisfy codes such as NFPA 54/ANSI Z223.1 and CSA B149.1.
Frequently Asked Questions
Q: What is the difference between ANSI Z21.84 and ANSI Z21.15?
A: ANSI Z21.15 covers manually operated gas valves for appliances that are attached directly to the appliance (e.g., range burner valves). Z21.84 covers valves intended for connection in the gas supply line, such as shut‑off valves, connector valves, and hose end valves. The leakage requirements and testing pressures differ between the two standards.
A: ANSI Z21.15 covers manually operated gas valves for appliances that are attached directly to the appliance (e.g., range burner valves). Z21.84 covers valves intended for connection in the gas supply line, such as shut‑off valves, connector valves, and hose end valves. The leakage requirements and testing pressures differ between the two standards.
Q: Can a valve certified to ANSI Z21.84 be used for outdoor grills without additional testing?
A: Yes, if the valve is specifically marked for outdoor use and has passed the temperature range test from –20 °F to 140 °F and the ultraviolet/weathering exposure requirements (detailed in Annex A of the standard). Always verify the valve’s listing mark includes the phrase “for outdoor use” or equivalent.
A: Yes, if the valve is specifically marked for outdoor use and has passed the temperature range test from –20 °F to 140 °F and the ultraviolet/weathering exposure requirements (detailed in Annex A of the standard). Always verify the valve’s listing mark includes the phrase “for outdoor use” or equivalent.
Q: Are there any special requirements for valves used with LP-gas (propane)?
A: Yes. LP-gas systems typically operate at higher pressure (11″ WC to 13″ WC for regulators, but the valve itself may see up to ½ psig). The standard requires that LP‑gas valves pass the same leakage and cycling tests, but the material compatibility must account for the higher vapor density and potential for elastomer degradation. In addition, the valve must be clearly marked “LP” to avoid cross‑use.
A: Yes. LP-gas systems typically operate at higher pressure (11″ WC to 13″ WC for regulators, but the valve itself may see up to ½ psig). The standard requires that LP‑gas valves pass the same leakage and cycling tests, but the material compatibility must account for the higher vapor density and potential for elastomer degradation. In addition, the valve must be clearly marked “LP” to avoid cross‑use.
Q: Does ANSI Z21.84 cover valves with integrated excess‑flow valves (EFVs)?
A: No, EFV function is not within the scope of Z21.84. When a valve includes an EFV, it must also comply with the applicable EFV standard (e.g., ANSI Z21.90 for gas connectors). The EFV performance is tested separately under that standard, while the manual valve portion must still meet Z21.84 requirements.
A: No, EFV function is not within the scope of Z21.84. When a valve includes an EFV, it must also comply with the applicable EFV standard (e.g., ANSI Z21.90 for gas connectors). The EFV performance is tested separately under that standard, while the manual valve portion must still meet Z21.84 requirements.
This article is provided for informational purposes only and does not substitute the full text of ANSI Z21.84‑2017. Manufacturers and specifiers should obtain the official standard from ANSI or CSA for complete requirements.
© 2026 — Technical Standards Advisory