1. Please measure the outer circumference of the head. If the cylinder processing is carried out in advance, please inquire with the company about the size of the predetermined outer circumference.
2. Please divide the outer circumference of the head into 4 equal parts and mark them on the cylinder and head.
3. Perform positioning welding, and the positioning points for positioning welding should be selected by the customer according to the diameter and plate thickness.
4. After the positioning welding is completed, proceed with welding. Pay attention to the protection of the surface of the stainless steel head. After the head is welded to the cylinder, the weld seam, heat affected zone, and surrounding welding slag, spatter, and pollutants should be cleaned in a timely manner, and PT inspection and surface acid washing should be carried out.
5. Prevent scratches and dents on the surface of the stainless steel head.
6. Prevent direct contact with carbon steel to avoid iron ion contamination.
7. Not stored outdoors, protected from rain.
8. Avoid forced welding. Structural design should prevent excessive restraining stress.
9. The chloride ion content in the water used for hydrostatic testing shall not exceed 25mg/L, and it shall be promptly dried after the test.
10. Stainless steel pickling cannot use reducing acids such as hydrochloric acid.
11. Strictly adhere to the compatibility of the medium as stipulated in the 'Capacity Regulations'. Note: For metastable austenitic stainless steel heads such as 0Cr18Ni9 and 304, surface pitting corrosion can easily occur due to improper surface protection. When combined with processing stress and welding stress, it leads to stress corrosion and intergranular corrosion. Therefore, customers are advised to pay special attention to the surface protection of this type of stainless steel.
Precautions for the use of sealing heads:
1. Carbon steel heads may crack in environments such as nitrate, ammonia, and alkaline sodium. Please specify the removal of residual stress when ordering the head.
2. Austenitic stainless steel may undergo stress corrosion cracking in specific environments with chloride ions. Please choose appropriate materials during design.
3. Carbon steel containers that require hot-dip galvanizing or aluminum infiltration should first undergo heat treatment to remove residual stress.