Maxitrol 12A04 Vent Limiter

The Maxitrol 12A04 Vent Limiter is a critical safety component designed for indoor gas pressure regulator applications where external venting is impractical or restricted by code. This 1/8" NPT brass automatic vent limiter features a precision ball-check mechanism that allows for unobstructed atmospheric inhalation, ensuring rapid regulator diaphragm response during the opening cycle. In the event of a primary diaphragm rupture, the device immediately restricts gas escapement to levels well within ANSI Z21.80/CSA 6.22 standards, effectively eliminating the requirement for dedicated vent piping to the outdoors. Engineered for reliability in low-pressure gas systems, the 12A04 is compatible with Maxitrol RV48, RV52, RV53, RV61, R400, R500, and R600 series regulators. Its high-grade brass construction is rated for temperatures up to 800°F, providing essential protection for HVAC contractors and facilities managers maintaining gas-fired appliances. For proper operation and safety compliance, the regulator must be mounted in a horizontal upright position when this limiter is installed.

• Eliminates Outside Venting: Meets NFPA 54 requirements for indoor installations, saving labor and material costs on vent piping.
• High-Performance Safety: Integrated ball check limits gas leakage during diaphragm failure while maintaining normal operational sensitivity.
• Wide Compatibility: Standard 1/8" NPT connection integrates seamlessly with RV and R series Maxitrol regulators.
• Rugged Brass Construction: Durable metallic body resists high temperatures and environmental stress in mechanical rooms.

• Can I use the Maxitrol 12A04 for outdoor installations? No. This device is strictly for indoor use or protected spaces. It should not be exposed to rain, snow, or ice, as moisture can block the vent port and cause regulator malfunction.
• Which gas types are compatible with this vent limiter? The 12A04 is suitable for use with natural gas, LP/propane, and mixed gas systems, provided the regulator inlet pressure does not exceed 0.5 psi (14" W.C.).
• Is specific orientation required for the 12A04 to function? Yes. To ensure the ball check functions correctly during a failure, the regulator must be installed in a horizontal, upright position.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.