The shell is a cylindrical part, open at both ends. The cross-section of the shell is most often a ring. We manufacture shells by the method of cold rolling.
- Internal diameter D 330 mm or more
- Thickness S up to 10 mm.
- Length L up to 2000 mm.
- Steel: carbon, low alloy, corrosion-resistant, heat-resistant, two-layer, etc.
Shells are made of materials suitable for cold working. We use only high-quality domestic materials to produce shells and other parts of the vessels in compliance with GOST and TU standards.
Shells are made from a single billet or a one welded from 2 or more parts in accordance with GOST R 52630-2012 standard. Shells from a single billet have a maximum size limit, due to the size of the original metal sheet of standard cutting pattern. Such standard sheet is up to 2,000 mm wide and 6,000 mm long. The width of the shell in this case is limited by the width of the rolls of the bending machine.
Any shell will have at least one longitudinal weld seam. The following methods of welding are most widely used in the fabrication of shells:
- Mechanized gas-shielded arc welding;
- Automatic submerged arc welding.
Welded joints must pass mandatory post-weld inspection. The following inspection methods are used:
- External examination and measurements;
According to the design documentation requirements, we can provide other inspection methods including destructive testing.
In the process of manufacturing a conical shell, the workpiece is fed into the rolls and by means of gradual rolling with the simultaneous vertical activation of the top roll, the product acquires the desired shape.
Technological parameters of the shells are restricted by the following factors:
- The minimum diameter is limited by the diameter of the upper roll of the bending machine. We produce shells with a diameter of 330 mm or more.
- The maximum diameter is up to 2,600 mm.
- The maximum wall thickness is limited by the strength of the upper roll, which is set by its manufacturer. We produce shells with a wall thickness of up to 10 mm.
- The minimum height is not limited.
- The maximum height is limited by the width of the bending machine rollers. We manufacture shells up to 2,000 mm high.
To add / restore the necessary mechanical properties of the shells, they are heat-treated after rolling, welding, and calibration.
The need for heat treatment during production is established by the requirements of GOST R 52630-2012 standard and design documentation.
In a number of cases, for further use of the shell in the process of vessel manufacturing, it is necessary to perform further processing. For example, treatment of the butt-end for welding on the head, fittings, bends and other parts to the shell, etc.
Manufacturers of tanks and pressure vessels, who have a pool of machinery, carry out such processing themselves. To such companies we supply shells without machining.
To the manufacturers of tanks and pressure vessels, who do not have a pool of machinery or special equipment, OOO Hermes-Ural is ready to provide additional services upon prior agreement with the Customer.