Certified vs. Non-certified Construction – Vent Limiting Devices
Maxitrol vent limiting devices meet ANSI Z21.80/CSA 6.22. The requirement states, “Vent limiters shall be of materials having melting points of not less than 800°F (427°C).”
Don’t be misled. Regulators using safety or double diaphragm vent limiter designs DO NOT COMPLY with the vent limiting device requirements stated in ANSI Z21.80/CSA 6.22 and MUST BE VENTED TO THE OUTSIDE.
In accordance with the National Fuel Gas Code NFPA54/ANSI Z223.1, the only line pressure regulators that are NOT required to be vented to the outdoors are line pressure regulators that are listed with approved vent limiting means. Regulators constructed with safety or double diaphragm vent limiting means ARE NOT LISTED as having an approved vent limiting means.