trap primer

I need to install a trap primer for a couple of new construction emergency floor drains, and I'm under the UPC. There are a few solutions which go between the drain and trap that allow a 1/2" FPT connection from the trap primer, but they are all very backordered as far as I can tell. However...

Can a expansion tank stop a trap primer from working properly?

I have a very loud gurgling noise coming from the laundry faucet opening and loud running water sound when no taps are on inside or outside the house. The faucet is a red and blue handled brass one piece faucet tap with a trap primer outlet. The outlet has a thin tube that runs under the floor...