ther,ostatic pipe union

Timco

Laars mod units use them. They have small holes for some flow, and open when the pri loop reaches the desired temp. Just a thermostat in them like a car would have. With it closed, it recirculates through a bypass...when open the pri loop gets the flow.

Tim

Robert Martin

thermostatic pipe union

Work done on old cold conversion gravity to forced hot water found a 2" general thermostatic union on supply before flow checks. this is rated at 100 degrees F. Any information would be appreciated. My 1938 Audel's don't even show it.