English to Russian Tech/Engineering Engineering (general)

1.2 The fitting manufactured by Parker (A-LOK) for transitioning from piping to tubing installed with compression fittings is called a Buttweld Connector. This connector could be socket welded to either the main line class (MLC) root valve or a full socket weld coupling depending on the installation detail used. The fitting could also be butt welded to a plain end MLC pipe nipple or section of pipe. The outside diameter (OD) of the buttweld end has the correct dimension for socket welding. For example, the OD of the 1” (25mm) ***buttweld connector is 1.310” (33.3mm) for socket welding to a valve or fitting with an inside diameter (ID) of 1.330” (33.8mm).

Я немного запуталась с последним предложением:
Если buttweld connector - это разъем под сварку встык, то почему дальше идет, что он используется "для сварки враструб"?
Или я все напутала?

Спасибо огромное!