при необходимости

см. тж. если потребуется; по мере необходимости

The plant permits inclusion of other elements for crushing, grinding, screening and concentration as may be required.

This equipment could be moved elsewhere as the need arose.

The bobbins may be put in parallel, if need be (or should the need arise), to increase the field strength.

The table shaft is hollow so that if required (or necessary), hydraulic lines can be ...

The device converts moderate pole spacing to fine pole spacing when needed.

Источник: Русско-английский научно-технический словарь на Gufo.me