multi air compressor installation tips

hello I am from the Philippines...I need your advise or tips on how to improve the output supply of our 2 air compressor and save power consumption as well...it is a screw type compressor connected in "T" to the main tank..one thing we notice is that the cut-off pressure of 6 bars can not be reached by this compressors...the service engineer inform us that the compressor has no problem and it has enough capacity but the line with "T" going to the tank has the effect of this pressure loss, he suggest to install "headers on each compressor before going to the tank...both compressor has check valve on it...one thing we are thinking is that we remove the "T" connection and directly install the line of each compressor to the main tank...I need your expert advise, if possible please give me diagram or any website that can help me with this problem...thanks a lot

regards,

jun