oil tank vent pipe size

[John Arnold]

Can someone remind me of the minimum size for the oil tank vent pipe?

[Jeff Remas]

1-1/4" per NFPA. They increased it to 2" then decreased it back to 1-1/4". If you start putting tanks in series then you may have to increase it is size depending on whether or not your areas has adopted the IFC or the NFPA. They differ in requirements.

[John Arnold]

Jeff - Thanks!