2015 ORS § 801.522¹
Tank vehicle

Tank vehicle means a commercial motor vehicle that is designed to transport any liquid or gaseous material within a tank or tanks having an individual rate capacity of more than 119 gallons and an aggregate rate capacity of 1,000 gallons or more that is either permanently or temporarily attached to the vehicle or the chassis. Tank vehicle does not include a portable tank having a rated capacity under 1,000 gallons. [1989 c.636 §7; 2013 c.237 §49]