where is a/c low pressure port?

Thanks, found it. They're both on the driver side, both black and the low pressure one is under the other one on a larger tube pointing down. That's why I couldn't see it. Put in 3 cans, leaked out again. I just got it back from the shop. $549 later new condenser and evaporator. If I had 189,000 miles on me I'd leak a little also. Bought it on 12/5/11 with 80,000 on it. Besides regular maintenance and tires, only other thing done to it was new radiator fans ( $400 ). Been a good car for a courier. Thanks again.