Arrangement for connecting manifold blocks

For use in operatively mounting a plurality of fluid control valves, a combination comprising a pair of valve mounting manifold blocks adapted to be stacked in aligned end-to-end abutment, the manifold blocks each having fluid passage means therein for conducting fluid controlled by valves mounted on an upper surface of the block, one block having an upper opening therein intermediate the ends of the block, a longitudinally extending slot and an end opening in one end of said one block communicating with the slot, the upper opening of said one block being accessible from its upper surface and intersecting the slot, the other block having a cavity and an opening in one end of said other block communicating with the cavity, the end openings in the blocks being registrable with one another when the blocks are in aligned end-to-end abutment, an elongated fastener having a head fixed on one end and an opposite threaded end, the fastener longitudinally extending from the slot in said one block into the cavity of the other block with the head of the fastener disposed within said cavity, and a nut received within the upper opening of said one block for threaded engagement with the threaded end of the fastener at the juncture of the upper opening and the slot for compressively engaging the ends of the blocks in fixed relation to one another.