Socket Hole on Water Pipe Line for Diff. Pressure

Hi friends

Am fixing pressure Transmitter for a water line, we had placed the Orifice and 15mm socket had been made on the top of the pipe-line on both sides of the orifice.

My question is, for calculating differential pressure of water, do socket hole should be made on the top of the pipe-line or bottom of the pipe-line...??? because for water line, flow transmitter the socket shld be place at bottom... do same case for calculating diff.pressure....??

Thanks