The 15 degree taper of the hubs is sufficiently large to make initial fitting and tightening easy.
50 to 100NB clamps are held together by 2-bolts and nuts while 150 to 300NB clamps are pulled up with 4 studs with self-aligning nuts. These clamps are all ANSI class 1500 (MPa) rated. All the fasteners are low tensile (grade 4.6), galvanized and have generous corrosion allowances.
An earlier range of two bolt clamps is also available for low pressure applications (ANSI class 900 and below – 16MPa).
The hubs are made of wrought steel with guaranteed properties and are factory welded onto the pipes. The weld is as simple as a normal butt weld done by code welders to a controlled standard.