Integral Manifold

Yes. The equipment manufacturer can, over the telephone.

If we're stooping as low as opinions, then I think that Anonymous Poster #1 is socially inept, and frightened to use the telephone.

Here is a Google tip, if you start a Google search with the command define: you will get a definition of the word or common phrase that follows the command.

They aren't necessarily different.

With only minimal description, I'll assume you're talking about instrumentation 3 or 5 valve manifold valves which I suspect some marketing guy calls "Integral Manifold".

A 3 valve manifold can easily isolate the transmitter from the process for installation or removal from the process and for a zero check. 3 valve manifolds might or might not have vent ports where each port has a needle valve, but 3 valve manifold always lacks the large T handle valves which make it easy to apply a test or calibration pressure. They only have 3 T handles, not 5 T handles.

A 5 valve manifold has two additional large T handle vent valves tied to vent ports which can be used to either vent pressure from the blocked off transmitter or to apply a test or calibration pressure.