10 days According to the query of Harbin welder certificate in official website, it takes 10 days for the green audit of welder certificate to be connected to the Internet. Welder's operation certificate belongs to the special operation industry certificate, valid for 6 years (IC card form, ID card size). The validity period is 6 years, the new certificate is reviewed once every 3 years, the old certificate is reviewed once every 2 years, and the expired certificate is invalid.