Heat and Frost Insulators Local 133

Heat & Frost Insulators Local 133 is a labor union based in Bismarck, North Dakota, United States. Established in 1962, the union's primary focus is to provide training, employment, and benefits to its members, who are skilled mechanical insulators. The union's contractors work in various industries, including power plants, refineries, and food processing facilities, throughout North Dakota and Northwest Minnesota.