I'm not sure I understand this question. Do you want to share the same loop? LT and PT give different value and reading from each other. Each of them has independent hard wire going to an individual AI channel at the DCS/PLC IO card so that each of the reading doesn't mix up with each other...
What type of LT that you are using? If it is DP LT, tubing length (horizontally) wont affect the reading and like georgeverghese mentions, once the line is flooded, it wont affect the reading as it's reading the pressure. However, you need to take into account the height of the tubing...
