A liquid separator for the separation of liquids from gases is disclosed. The separator has an inlet orifice for receiving a flow of the gas laden with liquid, a first outlet for the liquid and a second outlet for the gas liberated from the liquid, and an adjusting mechanism for varying the available cross-sectional area arranged in the inlet orifice. The inlet orifice has a tubular passage cross-section and is bounded along its entire length by a dimensionally fixed wall. The adjusting mechanism has a pressure control assembly having a pneumatically operable control element which is arranged within the inlet orifice in a manner allowing relative movement therewith.