The advantages of weld connection:
No need to drill on the steel, timesaving, no need to damage section of the material, to make full use of the material.
Any shapes of components can be connected directly, don't need auxiliary parts generally, connection is simple, short stress transmission line, widespread applicability.
Weld connection has good gas tightness, water tightness and rigidity. LF weld technique is approved by BV and SGS.
But weld connection also has problems during site operation: delivery inconvenience, high transportation cost, difficult site welding, long construction period etc.