ASME Sec. VIII

No - you must design as per Sec-VIII Div. 2 for the U2 stamp.

1. Can I put U2 stamp on the equipment which were designed by the requirement of ASME Sec-VIII Div. 1 rules.

Noooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo

2. If not what are the requirement to check to put a U2 stamp on equipment which were design by the requirement of ASME Sec-VIII Div. 1 rules

Nothing to check because it is prohibited. The certification starts with the first stages of design, ordering of materials, material receiving, procedure qualifications, and fabrication.

For example, U2 requires to proceed a UT for welded seam surfaces cut-ed by oxyacetylene, how do you will fulfill that requirement?