Abstract: A rotating disc gate valve for controlling fluid flow in a flow line comprising a valve body having a flow passageway and a cavity transverse to the flow passageway to receive a flow control assembly. The flow control assembly includes first and second valve seat carriers each having a plurality of valve seats thereon which are aligned to form valve seat sets and an independent rotation means for rotating the valve seat carriers whereby replacement valve seats can be axially aligned with the flow passageway without dismantling the valve body. The flow control assembly includes a flow control disc mounted between the valve seat carriers.