Steel vessels are made through a series of steps that involve the shaping, welding, and finishing of steel plates and components. Here’s a basic outline of the process:
- Design and Planning:
Engineers create detailed designs for the steel vessel, taking into account factors like size, pressure requirements, and intended use (e.g., for storage, transport, or industrial processes).
The design specifies the type of steel, thickness of plates, and dimensions.
- Material Selection:
The appropriate type of steel (often carbon steel or stainless steel) is selected based on the vessel’s requirements, such as strength, corrosion resistance, and operating temperature.
- Cutting the Steel Plates:
Large steel plates are cut into the required shapes using cutting machines such as plasma cutters, oxy-fuel cutters, or lasers.
The cutting is precise, based on the design specifications.
- Forming the Steel:
The steel plates are bent or rolled into the desired shape, such as cylindrical or spherical sections. Rolling machines are used to shape the steel for cylindrical vessels.
For larger vessels, multiple sections or parts may need to be formed separately.
- Welding:
The formed sections are welded together using different welding techniques (e.g., MIG, TIG, or arc welding).
The welding must be strong and flawless, as weak welds could lead to leaks or failure of the vessel.
Some vessels are built in sections and then assembled later.
- Heat Treatment (If Required):
After welding, some vessels undergo heat treatment to relieve stresses caused by welding and ensure the material maintains its strength.
This process involves heating the vessel to a specific temperature and then cooling it at a controlled rate.
- Surface Preparation:
The vessel is often sandblasted or cleaned to remove any impurities, oxidation, or weld slag.
For vessels that need corrosion protection, they may be coated with anti-corrosion layers or lined with other materials.
- Inspection and Testing:
The vessel undergoes several quality control tests, including:
Hydrostatic testing: The vessel is filled with water or another liquid and pressurized to check for leaks.
X-ray or ultrasonic testing: These are used to check the integrity of welds.
Visual inspection: Ensures that all surfaces are free of defects.
Other non-destructive testing (NDT) methods may also be used.
- Finishing:
The vessel is painted or coated as necessary to provide additional protection against corrosion or to meet specific design aesthetics.
External fittings, valves, or other components may be added depending on the vessel’s function.
- Assembly and Installation (If Applicable):
For large vessels, assembly might take place on-site.
Once completed, the vessel is installed in its intended location, and final inspections may be performed before use.
This process can vary depending on the size and type of steel vessel, such as pressure vessels, storage tanks, or ship hulls, but these steps form the core of steel vessel fabrication.