The bottom block freely dangles from the canister:



Looks kinda like they used to be connected by three short screws in the middle, which have now separated.

Are they supposed to be like that, or am I getting a new one?

 

No good get a new one

 

Cool, thanks!

 

Note the code and lettering stamped on the diaphragm shell/housing. There should be either a "P" or "N" stamped there, denoting whether the valve is a positive or negative backpressure type. That needs to be matched by the replacement valve.