My air compressor is a huge unit 14 horsepower and has a 1 1/4 pipe outlet. NOW my dryer cooler unit has only 3/4 inlet outlet/ HUH why is there a differance in diameters?? I also have to install a nitrogen generator system for filling the drag bike tires with air air shifter drag car tires and so on. Now alls here i bought lots of 1.25 dia pipe but Im confusedmn 3/4 on the dryer and inlet outlets with 1 1/4 dias on the cvompressor?? Can anyone shed some light ?? Thanx Madman