Помогите, пожалуйста, перевести эти словосочетания (completeley welded / single welded).

Контекст следующий:

The mixers are equipped with external serpentines for the thermal oil circulation for heating purposes on only part of its cylindrical surface and bottom. The serpentines are completely welded. The mixer bottom is heated by means of these serpentines totally (not with a double bottom, but a single welded serpentines), such is, covered for the 100% of its surface while the mixer cylindrical bodu changes then to a non full serpentine made of steel profile having a special pitch.