Can I use a 172.47.x.x range IP to communicate point to point with an EMC device and a storage server network adapter?

Point to point connections shouldn't need any additional routing, since they're on the same network. It will work.
Why would you ever want to use public IPs for this? Did someone not realize that 172.47.0.0/16 is public IP space?

For point to point connections, a /30 subnet mask (255.255.255.252) is appropriate.

If you use this network internally then there are two things that you need to make sure you don't do.

First, you don't want to use them on hosts that will ever have a need to connect outside of you local network.

Second, you absolutely don't want route announcements for this range anywhere in your network.

Both of these points go back to the same point.  As limited as the scope may be, should a host ever resolve the IP address for a third party site to the network you use, it will at best black hole, at worse, it will direct to an internal host.

As has been noted above, you need to shuffle off this network and use an actual private IP space.  I've seen folks do this in the past and have seen those same folks ready to jump out of windows because of the problems that can crop up.