This method consists of producing heads through the following steps:
Diameter 5000 mm
Processing and materials
Processing
PRODUCTION METHODS
Tecnofondi performs cold forming of dished heads both by deep drawing (pressed heads) and by deep drawing followed by spinning (spun heads).
Heads produced with these methods reach the following maximum dimensions:
Heads produced with these methods reach the following maximum dimensions:
WELDING
In cases where the sheet format is not of sufficient dimensions, a welding operation is performed.
Welding is performed in a workmanlike manner by qualified welders and according to a process itself qualified according to the following standards:
UNI EN 9606-1
UNI EN 15614-1
Welds – unless expressly requested – are not subjected to inspection.
For heads where X-ray inspection of welds is required after forming, this must be specified at the time of order.
Welding is performed in a workmanlike manner by qualified welders and according to a process itself qualified according to the following standards:
UNI EN 9606-1
UNI EN 15614-1
Welds – unless expressly requested – are not subjected to inspection.
For heads where X-ray inspection of welds is required after forming, this must be specified at the time of order.
TRIMMING AND FLANGE
Heads can be supplied with raw or trimmed edges. Trimming is recommended to achieve the exact height of the head and to obtain perfect edge flatness.
In addition to trimming, it is possible to perform flanging of the flat collar (so-called flange) which allows better insertion of the head into the shell.
In addition to trimming, it is possible to perform flanging of the flat collar (so-called flange) which allows better insertion of the head into the shell.
This operation is performed up to a maximum Ø of 1800 mm and up to a thickness of 6 mm.
TYPES OF EDGE FINISHESTHE PRESSING METHOD AND STAMPING
The pressing method consists of producing heads using standard dies mounted on powerful hydraulic presses which, starting from a sheet disc, produce heads conforming to the required profile with a single deep drawing operation.
Tecnofondi is equipped with a wide range of dies in both standard, torispherical and elliptical profiles, which are mounted on 6 presses ranging from 400 to 1500 tons with automatic or semi-automatic handling.
Tecnofondi is equipped with a wide range of dies in both standard, torispherical and elliptical profiles, which are mounted on 6 presses ranging from 400 to 1500 tons with automatic or semi-automatic handling.
Tecnofondi operates primarily with its own dies but is available to work with third-party equipment, or to manufacture dies according to specific customer requirements, providing consulting both for die construction and product manufacturing.
Toll Processing
Tecnofondi also produces heads on a toll processing basis. For such material, if it consists of discs, they must have ground edges and, if welded, with welds performed with X-beveled edges to obtain full penetration.
Furthermore, welding must be performed not on the original edges but after trimming the same to a depth of at least 20 mm in order to remove the part most subject to processing cracks (when using coil sheet this is not necessary).
Furthermore, welding must be performed not on the original edges but after trimming the same to a depth of at least 20 mm in order to remove the part most subject to processing cracks (when using coil sheet this is not necessary).
Sheets must also be assembled in the same rolling direction. If blanks are sent for toll processing, the dimension must be increased by 20 mm compared to that resulting from the disc.
In any case, for toll processing material, it is advisable to always request confirmation of developments before cutting the starting discs or blanks.
In any case, for toll processing material, it is advisable to always request confirmation of developments before cutting the starting discs or blanks.
THE SPINNING METHOD
- production of the starting disc (using plasma cutting table or circular shear);
- deep drawing of the disc using hydraulic presses with manipulator to obtain the spherical cap;
- flanging of the cap using flanging machines to obtain the finished product according to the desired diameter and profile.
With this method, Tecnofondi can produce all profiles and all diameters desired within the production range, working up to 32 mm thickness and 5000 mm diameter.
Materials
In general, we can process material with a maximum tensile strength of 750 MPa and with a minimum elongation of 22/24%.
Carbon Steel
Coils and carbon steel heads available in stock are in: S235JR according to UNI EN 10025-2 standard. Coils also in S355JR or J2.
All such material is suitable for hot-dip galvanizing, according to the following conditions:
- Maximum % of Si<0.03%
- % of Si+2.5P<0.09% (French standard AFNOR A (35-503/94))
We also have a carbon steel raw material warehouse of mill plate in S275JR according to UNI EN 10025-2 standard.
Stainless Steel
Heads and sheets to be processed in stainless steel available in stock are in AISI 304 and AISI 316 according to ASTM A240 standard.
DO YOU NEED MORE INFORMATION ON MATERIALS AND PROCESSING FOR DISHED HEADS AND SHEETS?
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