ifeanyi2013,
Based on your query, you have shown no real knowledge of welding, welding procedure qualification, welder qualification or the construction/manufacturing Codes governing welding. You need further education and mentoring by experts in welding and the applicable construction/manufacturing Codes. There are courses available that you should take to gain adequate experience should you be made responsible for the welding activities of your employer. Find those courses near where you reside or on the internet and enroll. Meanwhile, hire a consultant experienced in welding and the Codes of construction to mentor you and to assist your company in applying the appropriate welding technology for the Work to be done.