A fast-action direct-fluid (gas or liquid) actuated valve assembly including a valve housing having an internal fluid port defined by a larger chamber and a smaller chamber, separated by a shoulder, a valve body seated in the valve housing and defined by a plurality of ports evenly spaced circumferentially around its circumference adjacent to an endplate seatable in the housing, a plurality of supporting wall sections (mullions) between the ports, and a plurality of internal vanes 9 each running along a corresponding mullion providing reinforcement thereof. The vanes 9 are inclined and/or curved, and defined by rounded faces to promote a smooth circular internal fluid flow. A valve cap formed with an annular collar is affixed to the valve body, and the valve body 2 and cap/collar 7 are slidably carried in the valve housing 1 between an open position and a closed position. A toolset is also disclosed for easily installing and removing the valve assembly.