Yes, there is a check valve in the loop on the suction side of the pump.
Thanks for the orifice suggestion. I'm to get a globe valve in that line to keep the pump from running all the way out, but an orifice may be a better solution.
Thanks much for the sanity check on Location A.
To answer your question, we're controlling temperature in the loop (by controlling flow out of it). The header feeding the loop will force cold glycol in as the TCV opens to bleed off the excess.
About the seal leg: We inherited this piping...
We’re laying out a glycol system with a pumped loop around an exchanger where fresh glycol will come into the pump suction side of the loop. (See attached diagram) Due to physical-layout constraints, we put the valve in Location C, but will it work there? My concern is air leaking up past the...