... 2.API,CE,LRQA certificate 3.Usage in petroleum,chemical,electric power Welding carbon steel elbow1. Material: can be made to ... , LRQA3. Usage: Petroleum, chemical, water treatment, construction, electric power and so on.4. Wall thickness: SCH10-SCHXXS5. Model: 45Degree, 90Degree, 180Degree6. reasonable ...