So, I have a new replacement propane tank.  The only part I kept from the
old tank is the "splitter" that leads from the tank to the two lines going
in to the van (one fridge, one stove).

I'm wondering if there is some kid of thread compound or something I should
use when screwing that on to the tank output.

My understanding is that on the flared fittings you do not use any compound
(correct me if this is wrong).  But this isn't flared, it is just one block
of metal screwed in to another block.

mike