After 33 Years In Business, A Washington County Virginia Business Is Shutting Its Doors. Tri-Tube, Located In Abingdon, Is A Nationally-Known Tube Fabrication Supplier. The Company’s Owner, Art Porter, Told His Employees That His Company Will Close In Late April Or Early May Because Demand For Their Product Has Moved Oversees, Porter, A Coeburn Virginia Native, Said At Its Peak, Tri-Tube Had 160 Workers. When Tri-Tube Closes, That Will Make Seven Empty Buidings In The Washington County Industrial Park.