Smoke/Heat Detector ID

These pics are from Dixmont State Hospital which was a couple miles down the road from me before it was torn down. The system was a large Simplex 4208 with pulls in locking institutional cabinets and what I think were 4050’s or similar electromechanicals.

However, I’m not sure what these things are. These are the only photos I have of them:

Has anyone ever seen anything like these before? They kind of look like some sort of heat detector. They’re not sprinklers since they are located on pipes that run along the wall.

Looks like some folks went copper hunting :slight_smile:

Do you have a larger photo?