solenoids and solid state relays

All of the fluid transfers during the mashing process will be controlled by the computer which will open and close the solenoid valves and turn on and off the pump and heating element.  The valves are 304 Stainless Steel 1/2" npt  Solenoid Valves with viton seals from www.DudaDiesel.com.
These valve are normally closed and open only when 110 volts AC is applied.  To do this i will be using Solid State Relays or SSRs.  An SSR acts like an electrical switch.  The computer will put out a small dc voltage of about 5 volts which the SSR uses as a control signal that tells it to close the AC circuit and apply power to the valve. I will need 1 relay for each valve, the pump, and a special 40amp relay for the 240 volt heating element.