A pneumatic timing valve includes a spool and seal system having a first seal cartridge and a spool. The first seal cartridge has an annular body with radial ports. The spool is positioned within the first seal cartridge and movable between a first and second position. The spool has a central bore and radial ports that intersect the central bore. The radial ports of the spool complement the radial ports of the seal cartridge. The seal cartridge radial ports, the spool radial ports, and the central bore of the spool define fluid flow passages.
