T-DRILL flanging machines form a lip or flange directly on the end of the pipe allowing the use of loose flanges. This process saves up to 40 % of the time compared to traditional weld neck flange connections.
Advantages when using T-DRILL Flanging machines
- Cut workshop costs by eliminating the need for welding and X-raying.
- Reduce the need for working capital: no welding neck flange inventory or complex welding and X-raying equipment is required
- Loose flanges save installation time by eliminating difficult bolt-hole positioning.
- Provide precise results and constant high quality: no risk of weld or braze fractures
- Capable of cold and hot forming both long and bent pipes with either smooth or grooved flanged surfaces.
- Programmability makes them very easy to operate and practically maintenance-free.
The flange - also called the Van Stone and loose flange - is achieved by roll forming a flange on the end of the pipe spool. The flange can have a smooth or grooved face, depending on the forming (rolling) tool used.
A loose commercial flange backs up the formed pipe end; when the connection is made, a gasket is sandwiched between the two formed flanges, held together by the bolted commercial flanges. Since the flanges are loose, they eliminate welding and allow free rotation for alignment and bolt-up, providing so a significant cost reduction.
The flanging can be performed on cold or heated pipes:
Cold flanging is used for stainless steel, mild steel and copper alloys. The wall thickness of the pipe can be from 1.5 mm up to 5- 6 mm depending on pipe material and diameter. In case stress relieving is needed, the machine can be equipped with optional heating unit which can be used for heat treatment after flange has been formed.
Preheated flange forming can be used for stainless steels. Before flanging the pipe end is preheated to 200 - 300º C, which prevents work-hardening of the material during flanging. Preheating may be done by means of a heating unit which can be integrated to the machine or by heating the pipe by another method before flanging operation. The wall thickness of the pipe can be from 1.5 up to 5 mm
Hot flanging is used for carbon steels in case the wallthickness exceeds the cold forming limit or if heat treatment is found necessary. The pipe end is heated to about 900 - 950 ºC, in order to reduce the force required for the flanging. No further heat treatment after flanging is then necessary. The heating is done automatically by optional gas burner which can be integrated to the machine. The wall thickness of the pipe can be from 3 up to 8.8 mm depending on pipe diameter.