[VAC] water pressure relief valve

[Dick and Kris Parins <dkparins@xxxxxxxxxx>]

Some time ago I was referred to a Shurflo installation guide in response to
a question.  That guide showed what I remember as a pressure relief valve
just ahead of the water heater.  As I understood it at the time it was there
to prevent a water hookup from delivering too much pressure to the system.
I have looked over the old water system and find no such device.  Is this a
"modern" enhancement resulting fom too many ruptured water heaters?  Do I
need to install such a device?  Can it be installed right at the city water
connection or is it strictly for the water heater?  Thanks.

Dick
'62 Bambi