Question
Have a hydraulic sprinkler system that was installed sometime in the early 70's. The zone hydraulic diaphragm valves are brass, 1 1/4" inlet and outlet. Valve dimensions are approx. 6" long, 4" deep. The only id marks are an "I" with an imposed "C" in the middle of the "I" on the valve diaphragm cover, and flow direction arrows on each side.
Would you know who the manufacturer is?
Thanks for your time and help.

Answer
Hey Brad, I hope this helps. The only company that comes to mind is the Imperial brand. You will be lucky to find any parts for these old brass valves. It's also very hard to find any hydraulic valves anymore. You might be better off coverting the system over to electric. Sorry I couldn't be of more help. Thanks and have a great day.