I wasn't asking the difference between the pumps, I'm asking why you said I don't have the "head room" because I have a jet pump. Either way, if it's a jet pump or a centrifugal pump, it will be momentarily dead headed and will produce it's dead head pressure. Whether its 60 psi, 40 psi or 100 psi. I would like to get a PSV and set it for just under my dead head pressure so in the even that a valve fails the PSV will open and protect the pump. You say that a PSV is not a good idea for a jet pump. You mentioned that my shut off pressure is 65 and I operate at 60 - I don't, the pump operates normally in the 40-45 psi range, with the valve open.
What I'm really getting at is this: I see people recommend to others to have a PSV on their system. In a case like mine, where the pump is momentarily deaded head and produces deadhead pressure, how can you ever size a PSV that will open when your valve fails, but not everytime you start the system because the zone valves don't open fast enough.
And, I did read the tutorials. I googled stuff. Alot. I'm a chemical engineer and I work with pumps and piping systems everyday at work. This issue I am having is pissing me off to no end because I cannot figure it out. I wish I could just delay the pump relay from starting by 2 seconds and life would go on.