Apparatus and methods of dispensing fluid intravenously to a subject, and of flushing a line of an intravenous fluid administration apparatus, are provided. The apparatus may include a chamber including a plurality of connector ports and be configured to operate in fluid communication with an upstream source via a first connector port and, during operation, pass therethrough to downstream tubing, under a first pressure condition, first fluid from the upstream source via a second connector port. A third connector port may be configured to connect to an end of tubing or a valve connector such that, during operation, the chamber is configured to, under a second, higher pressure condition, pass therethrough to the downstream tubing a second fluid from a second fluid source via the third and second connector ports, prevent first fluid flow into the downstream tubing, and prevent second fluid flow through the first connector port.