Block Manifold with 8 - 1/2" FNPT portsBlock Manifold with 8 1 2" FNPT ports This Manifold has 8x 1 2" FNPT ports that are commonly used for connecting multiple columns or different tanks to one input of vacuum and or nitrogen. It has six ports on top and one on each end. The manifold has two 5 16 holes that can be used to easily mount on one of our extruded aluminum rack systems.