An example connector includes: a block having a plurality of through-holes; a clamp plate having a plurality of through-holes aligned with the plurality of through-holes of the block; and a plurality of fittings, each fitting having a first end inserted through a respective through-hole in the clamp plate to be received within a corresponding through-hole in the block. Each fitting has a second end opposite the first end and configured to couple to a tube. Each fitting has grooves for mounting a radial seal and a retaining ring. The retaining ring is disposed between the clamp plate and the block.