1. Please measure the outer circumference of the head. If the cylinder is processed in advance, please ask the company for the size of the predetermined outer circumference.

2. Please divide the outer circumference of the head into 4 equal parts and mark the cylinder and the head.

3. The positioning point of positioning welding shall be selected by the customer according to the diameter and plate thickness.

4. Welding shall be carried out after tack welding. Pay attention to the protection of the surface of the stainless steel head. After the head and cylinder are assembled and welded, the welding slag, spatter and pollutants in the weld, heat affected zone and surrounding areas shall be cleaned in time, and Pt inspection and surface pickling shall be carried out.

5. Prevent collision and scratch on the surface of stainless steel head.

6. Prevent direct contact with carbon steel and avoid iron ion pollution.

7. It shall not be stored in the open air and protected from rain.

8. Avoid forced assembly welding. Structural design shall prevent excessive restraint stress.

9. The chloride ion content of water for hydrostatic test shall not be greater than 25mg / L, and it shall be dried in time after the test.

10. Reducing acid such as hydrochloric acid shall not be used for stainless steel pickling.

11. Strictly comply with the medium compatibility specified in the code. Note: for metastable austenitic stainless steel heads such as 0Cr18Ni9 and 304, it is easy to cause surface pitting corrosion due to improper surface protection. Stress corrosion and intergranular corrosion will be caused when it is superposed with machining stress and welding stress. Therefore, please pay special attention to the surface protection of such stainless steel.

Precautions for use of head:

1. Carbon steel heads will crack in the environment of nitrate, ammonia, alkaline sodium, etc. Please explain how to eliminate residual stress when ordering heads.

2. Austenitic stainless steel will have stress corrosion cracking in the specific environment with chloride ions. Please select appropriate materials during design.

3. For carbon steel vessels requiring hot galvanizing or aluminizing, heat treatment shall be conducted first to remove residual stress.