Boiler/chiller tower piping

I am going to replace an old Boler 450Btu, was once a coal fired, converted to oil and now power gas . I also have a cooling tower currently functioning well . This equipment is in a Motel and now summer, a good time to change boiler out. The boiler is piped w/ 2 1/2" steel and one pipe supply and return. When they want to switch from heating to cooling or vice versa they use the old gate valves and then throw breakers to power up. All I want to have at this point is a diagram and or material list including all three way valves, shock tank, exp. tank and a control center to operate the system a little more efficiently. I have installed many Boilers , how ever I am not familiar with any near boiler piping or controlling when it comes to a chiller tower being involved.
If anyone can steer me to someone who can guide me through this list and drawing I need I would be thrilled.
Thanks Larry

 

This needs to be moved to the hvac forum