Pressure Control

Hello, I am working with a Siemens 1200 PLC. I have two pressure transmitters that I am reading in the PLC, as well temperature of tank A and tank B. I am trying to figure out the logic to control the pressure of tank A and tank B. As the pressure deviation changes the heater for each respective side will increase or decrease the temperature to compensate for the pressure change until the pressures are balanced. For example, if side A pressure starts to decrease, the side A heater will decrease the fluid temperature, thereby increasing the pressure until it is within 100psi of side B pressure. Let me know if you need any more information so you could help me with this problem. Thank you in advance.

If I read you right, you are trying to control pressure by heating or cooling a material. If so, this must be a slow system...

Also, you mention decreasing fluid temperature will increase pressure? I'm confused by this but maybe I don't understand fully what is going on. Generally when you heat something up, the pressure goes up as well.

it sounds like an assignement, and you will need a table of temperatures and pressures of the liquids.
100 psi is a lot