Русско-английский идиоматический словарь по космонавтике - служить для

The stop valves serve for cutting off propellant flow through a pipeline.

The filters serve to remove moisture and mechanical impurities from gas.

The vent (bleeder) valves are used to release liquid propellant vapour or gas from certain pipeline sections…

Gate valves are intended to fully or partially shut off a pipeline cross-section…