1. Please measure the outer circumference of the cap. If the cylinder is processed in advance, please ask the company for the size of the predetermined outer circumference.
2. Divide the outer perimeter of the cap into four equal parts, and mark the cylinder and the cap.
3. Carry out positioning welding. The positioning point of the positioning welding should be selected by the customer according to the diameter and plate thickness.
4. After the tack welding is completed, perform welding. Pay attention to the protection of the surface of the stainless steel pipe cap. After the pipe cap and the cylinder are welded, the welding slag, spatter and pollutants in the weld seam, heat-affected zone and surrounding areas should be cleaned in time, and PT inspection and surface pickling should be carried out.
5. Prevent bumps and scratches on the surface of the stainless steel cap.
6. Prevent direct contact with carbon steel and avoid iron ion pollution.
7. Do not store it in the open air, and keep it away from rain.
8. Avoid forced welding. Structural design should prevent excessive restraint stress.
9. The chloride ion content of water for hydrostatic test shall not exceed 25mg/L, and it shall be dried in time after the test.
10. Reducing acids such as hydrochloric acid cannot be used for stainless steel pickling.
11. Strictly abide by the media compatibility stipulated in the “Compatibility Regulations”. Note: For metastable austenitic stainless steel pipe caps such as 0Cr18Ni9 and 304, it is easy to cause surface pitting corrosion due to improper surface protection. When superimposed with processing stress and welding stress, it leads to stress corrosion and intergranular corrosion. For this reason, customers are requested to pay special attention to the surface protection of this type of stainless steel.
Points for attention when using pipe caps:
1. Carbon steel pipe caps will crack in the environment of nitrate, ammonia, alkaline sodium, etc. Please specify to eliminate residual stress when ordering caps.
2. Stress corrosion cracks will occur in austenitic stainless steel in a specific environment with chloride ions, please select the appropriate material during design.
3. For carbon steel containers that need to be hot-dip galvanized or aluminized, please do heat treatment first to remove residual stress.
Author: Maria
Post time: Jun-07-2023