A283 grade C plates API Std 650 welded storage tanks

Structural shapes of 9% and 5% nickel steel may be furnished to the chemical and physical requirements of ASTM A353, A553, or A645. Physical tests shall be in accordance with the requirements of ASTM A6.
API Std 650 welded storage tanks used Piping, Tubing, and Forgings
Material used for piping, tubing, and forgings shall be compatible in welding strength, and thermal expansion coefficient with the tank shell material. In addition to the specific requirements of this appendix, all piping within the limitations of 1.3.2 shall fulfill the minimum requirements of ASME B31.3.

Test welds of each API 650 tank nozzle and manway reinforcing pad (or each section of multiple piece pad) using dry air and apply a soap solution test in the presence of Purchaser's Inspector before hydro testing the API Std 650 welded storage tanks tank. Tap one inch NPT test hole in each pad or section.

In order to prevent the deformation of the bottom of metal vertical API Std 650 welded storage tanks during welding, comprehensive control measures such as strict control of assembly geometry size, reasonable welding procedure, process control of welding deformation and rigid fixation are adopted during assembly welding. The specific methods are as follows:
1. Strictly control welding groove forming of API Std 650 welded storage tanks.
2. Strictly control the size of tank welding seam assembly.
3. Define the welding sequence of tank bottom plate.
4. Reasonable distribution of welders.