Connect 6 inch camlock coupling to 3 inch camlock coupling

A 6 inch cam-and-groove line steps down to a 3 inch camlock through a reducing camlock adapter, a single part that carries a 6 inch cam profile on one end and a 3 inch profile on the other. Both ends still mate only to their own opposite camlock half, so pick the type (A to F) for each end. The step is two nominal sizes, which a reducing camlock covers as one component.

A reducing camlock changes size but not the cam type, so a 6 inch Type A on one end still needs a Type C, D or E half to mate. Confirm the type at each end, not just the 6 to 3 inch size step.