Abstract: A single-operation valve assembly useful in such braking system applications, as well as others, includes a flow passage and a valve member located within the flow passage at a first position in which the valve member prevents fluid flow from an upstream side of the valve member to a downstream side of the valve member. The valve member and flow passage are configured for movement of the valve member from the first position along the flow passage to a second position along the flow passage when a pressure difference between the upstream side of the valve member and the downstream side of the valve member exceeds a threshold level. The valve member and the flow passage are also configured for free flow of fluid along the flow passage in either direction when the valve member moves to the second position. Thus, in a braking system circuit the subject valve assembly does not interfere with fluid flow in the circuit after the valve member has been blown to the second position.