Depends of the current draw of the pump and if there is any other load on the circuit.
Inlet line will be bigger then the outlet line. on the contrary on my motorcycle fuel pump, the inlet and outlet are the same size!
Your electrician is correct on this. However, the pump is designed for 230V and will use less electricity, thus saving money if wired for 230V. Yeah, if you have to rewire for 230 V then it would be more expensive until your savings had consumed or offset the expense.
A reciprocating pump is more likely to get damaged first if its outlet valve is closed because it generates more pressure when the outlet is closed, leading to potential damage to the pump components. Centrifugal pumps, on the other hand, are more tolerant to operating against a closed outlet valve due to their design that relies on fluid flow rather than pressure build-up.
The pump should have a marking on it in the form of an arrow, "to carb" or "carb", or an "in" & "out" on it near the inlet and outlet ports (normally the bottom but depends on the mfg of the pump).
what is the type of pump three phase or single phase
The 230v breaker is 2-pole, The 115v is only single-pole so YES you need a new breaker. DON'T use 2 single-pole breakers instead. The well pump will run to the pressure setting of the pressure switch controlling it, regardless of HP. The difference might be in the size of the pump in flow rating, I.E. a 1/2 HP pump rated at 10gpm @ 70 psi won't perform the same as a 3/4 HP pump rated at 20 gpm @ 50 psi. Check the pump curve and pressure switch setting. The pressure switch for the new pump will need both power leads connected to the switch (1 lead per contact set), not 1 wire as the 115v motor was.
located in the water pump outlet.
S=iv 460=115*i Therefore i = 460/115 i = 4 Amps
It can be in either location, depending on your head pressure ie a circ on the head or "pump away" will circulate water better in upper floors. If the system is in a 2 or 3 story house using standard baseboard, then having the circulator in either position wont matter. Most all manufacturers are shipping and or directing installers to pump away...circulator on the supply....
The Circulatory System of the body is a simple plumbing system with a central pump, and a bunch of pipes that carry the Fluid around. The pump (heart) has an outlet and an inlet. The arteries are connected to the pump's outlet and the veins are connected to the pump's inlet. So, there you have it.
it is the pressure difference between inlet and outlet of pump.
I have had success with Pondmaster magnetic pumps. I suspect that your 80 Hz description is really 60 Hz. The important thing in pond pumps is how many gallons per hour you want to pump and how high you want to pump the water. Not knowing your application it is hard to size a pump for you. The 115V tells us nothing. The physical size of your pump may be a clue. You should be able to get a submersible pump for under a hundred dollars. Make sure the pre-wired cord is long enough to reach your power source.