pipeline and flange, Three Contacts, curved prime welding request vertical, welded joint light entire, burr without any crack, entrapped slag,or weld defects and so on ;

• 管道与法兰、三通、弯头等的焊接要求垂直，焊缝光整，不得有裂纹,夹渣,毛刺等焊接缺陷；