Abstract: A valve-coupling assembly comprising a manifold electromagnetic valve and couplings fitted thereto. The manifold electromagnetic valve is connected to the actuators through tubes respectively, and controls the operations of the respective actuators. Connecting members, each having pipe couplings connected thereto with tubes respectively, are detachably mounted on either one of the electromagnetic valves and a manifold block. With this arrangement, either of a manifold piping system and a valve piping system is selected. Either of a smaller-diameter tube and a larger-diameter tube is selectively connected to the aforesaid pipe coupling. Fastening of the tube connected and fastened to the pipe coupling is released by a fastening-releasing member, whereby the tube is easily removed and replaced by a tube having a diameter of a different size.