Production

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1. Annealing

Key to annealing tubes is to reengineer the molecules to return as they are used to be before welding. The tubes are strengthened as a result of this method.

We anneal our tubes with 1100 degree Centigrade thereafter cool down with at least 10 seconds, depending on their outside diameter.

 

2. Pickling

We pickle our tubes in the diluted acid around 15 minutes for cleaning and shining textures.

 

3. Polishing

For stainless steel tube, the smooth texture is not only shiningly elegant but also easy to maintain, clean up and sterilize in order to retain long hygienic condition. We used abrasive with high number of grit to smoothen the texture.

There are two specifications of our products, which are always polished.

Firstly, ornamental tube, ASTM A-544, is normally polished by abrasive with grit number 400 for our products in stocks.

Secondly, sanitary tube, ASTM A-270 which is mostly used in food industry, requires to be polished both inside and outside textures. Normally it uses abrasive with grit number 180 for both inside and outside texture, while Toyo Millennium use grit number 320 and 180 for the inside and outside respectively.

For Roughness value of the inside texture, you can check it out in section, Roughness Test, one of our quality assurance tests.

 

4. Marking

On our marking, we put information which is company's name, grade, heat number, and specification number. There are 3 types of marking, Sticker, Ink-jet screen and Etching.

For sticker label, we put it on outside of sanitary tube ASTM A-270 and inside of ornamental tube ASTM A-554. For heat exchanger service tube ASTM A-249 and A-269 are marked by ink-jet screen. Only for special requirements, all types could be marked by etching.

 

5. Packing

Our products are packed or bundled carefully and handled by secure lifts to ensure safe delivery until they reach our customers.

Considering individual tubes, especially, for sanitary tube ASTM A-270 which requires the hygienic condition, we pack each tube in plastic sleeves and capped its both ends with plastic caps for every single tube before putting them all into a case. As a result, the tubes will be clean and untouchable until customers open the packages. For ornamental tubes ASTM A-554, we pack in plastic sleeves individually before putting into a case as well.

Depending on specification of tubes or other conditions, we usually pack our packages in different ways as follows.

  1. Case – Packed into a steel box with strong beams. Inside a case, all tubes need to be covered by plastic warps and plastic pampers.
  2. Hexagonal Bundle – Hexagonal shape is physically secure to be bundled and carried since all tubes can distribute its self-weight among one another in order to avoid delivery damage.
  3. Triangular Bundle – Like hexagonal bundle, triangular bundle is only applicable in case the order is small or contains less quantity