Impact moulding with the ASS®-moulding systems
Impact purging with ASS®-Prime Shock forming is a special method for preparing the forming chamber for the welding process. Gas is allowed to flow into the forming chamber at an increased flow rate of 30/40 litres/min. As the oxygen is displaced, the moisture in this area is also displaced at the same time. The ASS®-Prime forming system was specially developed for this method.
How impact moulding works
The forming chamber is brought to the required inert gas atmosphere in a short time; the aim is to quickly reduce the O₂ content on the root side.
Flow stabilisation & distribution:
The increased gas flow quickly flushes the forming chamber, efficiently displacing the oxygen.
Fast rinsing:
In ASS®-Opti and ASS®-Opti M, sintered metal inserts ensure a throttled, even outflow - this stabilises the atmosphere in the chamber area.
Humidity:
The increased gas flow not only ensures time-saving displacement of the oxygen, but also the escape of moisture, which is a decisive factor for the quality of the weld seam root.
Oxygen-free environment:
The best possible oxygen-free environment is achieved in the forming chamber within a short time, which is necessary to avoid discolouration and other undesirable effects on the root-side weld and its surroundings.
Example from practice:
7 ppm - 0.0007%
27 ppm - 0.0027%
100 ppm - 0.0100%
ASS®Prime - Efficient joint forming for high-quality weld seams
The ASS®-Forming systems at a glance
ASS®-Prime (inflatable, ~50-1200 mm pipe ID)
Two forming bubbles (Primary/Secondary-Bag) form a defined chamber around the seam. Shock moulding with ~35-40 l/min lowers the Residual O₂ up to about 5 ppm; Up to 50 % shorter forming times are documented. Thanks to its flexible, modular design, Prime is also suitable for long distances and pipe bends; overpressure protection is integrated.
ASS®-Opti (98-320 mm pipe ID)
Permanently bonded construction for Fast set-up times, 3-lip sealing discs for secure sealing and hold, sintered metal for homogeneous gas distribution. The concept "1 sealing disc → 4 applications" (Flex, Fix, Single, Flange) enables a wide range of applications. The Shock moulding speeds up the rinsing process noticeably here too.
ASS®-Opti M (43-97 mm pipe ID)
For Small pipes and Narrow pipe guides. Symmetrical structure (identically designed inlet/outlet) facilitates insertion and positioning; permanently mounted "basic unit" for quick replacement of sealing discs; Sintered metal for smooth gas flow; 3-lips for secure hold - even in bends. The system is designed for Shock moulding designed to handle small volumes Very fast conditioning.
ASS®- Pipe plugs
ASS®- Pipe plugs are the favourable alternative to the Holzer ASS®- Forming systems: fast handling, reliable sealing of the pipe ends and targeted shielding gas supply. For pipe inside diameters Ø 9-115 mm, Effective against draughts - available on request as a case set with sealing discs in all sizes. When used with shielding gas fingers, the shielding gas is introduced in a targeted manner.