I recently installed a brazed plate chiller system using 8 15ton 06D compressors. The discharge line size from the manufacturer was 1 1/8". Manufacturer guidelines called for an increase in line size to 1 3/8" if line distance was more than 50 ft. I used a coupling to make the increase in line size at the discharge service valve. Upon completion the customer asked me if line size really mattered since there was still 6 inches of 1 1/8" line off the discharge valve. I would like to know if this is a problem. Been running for few months with no problems yet.