A gas delivery and purging device for an additive manufacturing chamber includes at least one flexible gas tube having a gas inlet, a purging gas outlet, and a sidewall which defines a shape of the tube, and a source of purging gas operatively connected to the at least one flexible purging gas tube for selectively delivering the purging gas to the at least one flexible purging gas tube. The gas outlet includes pores defined in substantially an entire surface area of the sidewall such that the purging gas passes through the pores and is thereby released into the chamber and is suitable for delivering a large volume of purging gas in a laminar flow.