Thread size of in-wall convectors

ajs317

This may be a long shot, but I’m planning to re-pipe my monoflo system with PEX home runs and is like to run the PEX all the way up to the threaded connections on my convector units. Does anyone know what the thread size might be on the elbow that connects the supply and returns to the finned tubes (see attached pictures)? I’m assuming it’s either 1/2” or 3/4” NPT, but I’m bad at eyeballing the sizes. Thanks.

HVACNUT

The pipe looks like 1/2" going into a 3/4 x 1/2 bushing so your able to bring 3/4" home runs to the boiler. Just remove the bushing.

ajs317

Thanks!