Bomb Funds. How they are produced
Rounded bottoms are used, in the vast majority of cases, as an end element of pipes or tanks.
The production process involves making the bottom from a sheet of metal that is cold-formed through the deep-drawing process.
Cold stamping is carried out by presses, mechanical or hydraulic, equipped with a mould to obtain the bottom with the defined characteristics.
At this stage, it is very important to correctly calculate the dimensions of the starting sheet. This is to avoid excessive waste of material or that too much or too little material can compromise the forming operations.
In addition to the obvious increase in processing costs, an incorrect use of the machines could lead, in the long run, to a deterioration of the tools themselves.
After the moulding phase, a series of machining operations allows a bottom to be obtained in line with all the parameters required by the customer:
- Trimming. This is used to eliminate the excess sheet metal until the correct height of the bottoms and perfect flatness of the edges are obtained.
- Radiusing. This is used to remove any burr formed both inside and outside the edge, rounding off the edges on both sides at the same time.
- Edging. Can be standard or customised according to customer requirements.
Types
Depending on the type of convexity and edging, we can identify different types of bottoms. As far as the type of cambering is concerned, generally the two most commonly used bottoms are:
- Elliptical bottoms,
- Torispherical or decinormal bottoms, i.e. in which the radius of the convexity is equal to the diameter of the bottom.
The different characteristics are useful depending on the construction requirements or the need to comply with special regulations such as PED, ASME or MOCA. Obviously, this also affects the choice of materials, even if the most commonly used raw material is steel, stainless or carbon.
In general, however, we can say that the decinormal bottom is the most advantageous for the quality/cost ratio. It is also the most versatile as it can be used in a variety of sectors: food, chemical-pharmaceutical, thermo-sanitary, for storage tanks or for transport.
Finally, each bottom can be customised with specific machining, including:
- Flanging
- Drilling
- Sleeve welds
- Slabbing
