apparatus , and method , for controlling the flow of dilute solutions of polymers such as dilute aqueous solutions of partially hydrolyzed polyacrylamides without causing any significant degradation of the polymer comprising the solutions . in one embodiment , the apparatus comprises a plurality of fixed restrictions connected in series with nipples having a larger internal diameter than the fixed restrictions . in another embodiment , the apparatus comprises at least one fixed restriction in communication with a flow control valve such as a needle valve .