November 23, 2020
There are two methods involved in manufacturing the basic metal structures of storage tanks. They are the plate-by-plate method and the coiling method. Below is an overview of their roles and function.
The first method of construction of storage tanks is the plate-by-plate assembly of the shells, bottoms and roofs. Shell and bottom assembly (welding) is carried out on the construction site. The main factor determining the quality of the tank metal structures, produced by this method, is strict provision of their shape (referred to the design project), and the set of technological decisions, preventing residual distortion of the metal frameworks in the course of edging and transportation.
The basic stages of plate-by-plate production of vertical tanks’ shells and bottoms are as follows:
The first stage includes preparation of shell and bottom plates. This stage ensures meeting the planned dimensions and geometric parameters. Pre-welding edging is also done. Extreme shape deviations of the plates are controlled in the course of preparation. The company’s Technical regulations set the maximum width deviation within the limits of ±0,5 mm.
Rolling is done afterwards, meeting the radius, planned by the engineering design project. Rolling gives the cylindrical shape to the tank shell while installation is carried out. This equipment gives the opportunity to make the radius equal within the whole length of the plate. The radius is checked by the pattern. The clear gap between the pattern (2 m) in an arc and the bent plate surface should not exceed 3 mm. Another rolling quality parameter is the waviness of the front edge. It may not exceed 4 mm on the whole length of the sheet. The waviness parameter per 1 m of sheet length should fall into the limits of 2 mm.
This method is one of the two industrial approaches for manufacturing the metal structures of a storage tank. It implies that tank shell, bottom and roof are brought to the construction site in the form of coiled strip panels, meant for welding. The advantages of this method are to be seen in making the tank installation period 3-4 times shorter as a result of cutting down the volume of welding procedures in the building area by about 80 % at the average and providing high quality of welding joints due to the use of two-side automatic welding.
Strip panels are produced from steel plates of modular size 1500×6000 mm. Panels are automatically welded on a special coiling machine. It consists of welding and assembly sites – top and bottom level, edging tumbler and rolling (coiling) device. Coiling machine’s operation is performed in two basic schemes (upper and lower coiling). Lower coiling is meant for manufacturing tank shells up to 18 mm thickness, upper coiling is used for thicknesses not exceeding 16 mm. The length of the coils amounts to 18 m, the weight is adjusted to the load-lifting capacity of motive power.
Eurotankworks. (n.d.). Manufacturing of Basic Metal Structures of Storage Tanks . Retrieved November 6, 2020, from Eurotankworks: https://eurotankworks.com/steel-tanks-fabrication/site-built-tanks-fabrication/
Fusion - Weld Engineering Pty Ltd
ABN 98 068 987619
1865 Frankston Flinders Road,
Hastings, VIC 3915
Ph: (03) 5909 8218
Optimized by NetwizardSEO.com.au