Key Points to Note When Using Pipe Cap

1. Measure the Circumference: Please measure the outer circumference of the head. If the cylinder is processed in advance, inquire with the company about the predetermined outer circumference dimensions.

2. Marking: Divide the outer circumference of the head into four equal parts and mark both the cylinder and the head.

3. Positioning Welds: Perform positioning welds. The customer should select positioning points based on the diameter and plate thickness.

4. Welding: After positioning welds are completed, proceed with welding. Pay attention to the protection of the stainless steel head surface. After welding the head to the cylinder, promptly clean the weld seam, heat-affected zone, and surrounding slag, splashes, and contaminants. Conduct PT inspection and surface pickling.

5. Prevent Surface Damage: Prevent scratches and impacts on the stainless steel head surface.

6. Avoid Direct Contact with Carbon Steel: Prevent direct contact with carbon steel to avoid iron ion contamination.

7. Storage: Do not store in the open air to avoid rain exposure.

8. Avoid Forced Assembly Welding: Avoid forced assembly welding. Structural design should prevent excessive restraint stress.

9. Hydrostatic Testing: The chloride ion content in the water for hydrostatic testing should not exceed 25 mg/L. After testing, dry it promptly.

10. Pickling: Do not use hydrochloric acid or other reducing acids for stainless steel pickling.

11. Medium Compatibility: Strictly adhere to the medium compatibility specified in the "Pressure Vessel Code". Note: For metastable austenitic stainless steel heads such as 0Cr18Ni9 and 304, improper surface protection can easily cause surface pitting corrosion. When combined with processing stress and welding stress, it can lead to stress corrosion and intergranular corrosion. Therefore, customers should pay special attention to the surface protection of such stainless steels.

• Points to Note in the Use of Caps:

1. Carbon Steel Caps: Carbon steel heads may crack in environments with nitrates, ammonia, and alkaline sodium. Please specify residual stress elimination when ordering heads.

2. Austenitic Stainless Steel: Austenitic stainless steel may suffer stress corrosion cracking in specific environments with chloride ions. Choose appropriate materials during design.

3. Hot-dip Galvanizing or Aluminizing Carbon Steel Vessels: For carbon steel vessels requiring hot-dip galvanizing or aluminizing, perform heat treatment first to remove residual stress.