Fitted together with another maintenance unit of the same type. и далее объяснение, как это сделать:
1. Remove the connecting flanges from the sides of the device which are to be fitted together.
2. Screw a threaded bolt into the central unit.
3. Remove connecting flanges from the additional unit and extract the spacer bolt.
4. Fit the additional unit with a connecting flange. Remember to insert seals between the individual units and the connecting flange.

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Спасибо за помощь!