What is the minimum height for a vent pipe above a roof when inerting or purging?

The minimum height for a vent pipe above a roof when inerting or purging is 3 feet. This requirement ensures that the vent pipe is positioned adequately to prevent the accumulation of flammable vapors in proximity to the roofline, which could pose a safety hazard. A vent pipe that is too low may not effectively disperse these vapors, increasing the risk of ignition and subsequent fire hazards.

Maintaining this height allows for proper ventilation, ensuring that vapors can safely escape into the atmosphere without being drawn back into the building or remaining in an area where they could cause an explosion or fire. Specific regulations and standards, such as those from the Oregon Department of Environmental Quality, emphasize the importance of adequate venting in the safe operation of heating oil systems.