Centrifugally cast tee is the better choice
At first glance, centrifugal castings may not be the obvious choice for outlet manifold tees. While some designs do not specify a preference for centrifugal over static cast tees, its superior metallurgical structure and weldability deliver long term performance and cost benefits. Reformer engineering experts report lower repair rates for centrifugally cast tees and better weldability; there are solid technical reasons for that. Lower inclusion rates for centrifugals result from a manufacturing process that forces impurities to the bore which are then removed. Centrifugal castings in a permanent mold typically have lower carbon and nitrogen levels than sand castings avoiding conditions that lead to weld cracking. A finer centrifugal grain structure produces a more weldable part less susceptible to porosity and leaking. Don’t be mislead by the t-shape. Technically, centrifugals are the best choice.