CLHaines,
These kind of questions are not accepted in these forums by rule. The equipment, you are questioning about, are not rare and they are common to HVAC systems. I suggest you to refer ASHRAE handbooks where you have pictorial explanation of the equipment and systems. You can make good use of Google, as well. Posts of similar kind may warrant red flagging in future. Please ask questions that bother you technically and we try to help you.
Good luck,