Can a burst pipe in a Hydronic heating system cause flooding until the water is shut off manually or does the system shut itself down and stop the water flow?

Most residential systems have a direct waterline connection to the main waterline servicing the home and unless a special pressure DROP differential valve has been installed the broken pipe will flow water until someone turns off the water manually.

Most residential systems have a direct waterline connection to the main waterline servicing the home and unless a special pressure DROP differential valve has been installed the broken pipe will flow water until someone turns off the water manually.

Can the "special pressure DROP differential valve" be installed at the main waterline thus safeguarding both the house and the heating system from flooding?