The Model J01 outlet fittings are designed  to provide you with a threaded outlet at any  desired location along the header. Made of  highly weldable SAE J403 forged steel the  Model J01 is designed for single pass welding.  The precision machined mouth is designed to  fit the first listed header size perfectly, and  allows only a small gap along the longitudinal  centerline of the second listed header size.  The Model J01 features a counter bore (dim.  C) and a 1.6mm land around the full  circumference of the mouth, which helps  ensure full penetration welds and minimize  the likelihood of any burn through or  distortion that might be caused by excessive  heat. The Model J01 is UL / cUL listed and FM  approved for service up to 300 psi (20 bar).

The hole cut in the header pipe can be cut  prior to or subsequent to welding of the  fitting. If holes are cut prior to welding, as  some codes require, follow the recommended  welding procedures to avoid shrinkage  and/or distortion of the header pipe.  Caution: Excessive heat may cause the  threads to distort and or leak. When holes  are cut after welding, the pipe remains intact  and thus may reduce shrinkage or pipe distortion.