SylvanLMP
The simple answer is the piping supply has been reduced to ONE FORTH of the origional size
About sucking air in when the pump kicks in.Hey ANY NON code approved ball cock will allow air to be sucked in ( this is why a vacuum breaker is designed to prevent VACUUM).
Having a one Horse power pump being supplied from a 3/4″ pipe is really not prudent.
Think about hydronic circulation with a 1/6 HP power motor EVEN on
a 2″ line. The reason I said forget the Galvanized pipe is the reduction would be the very 1st thing to get rid of. REMEMBER we are not talking Pressure loss AND volume.
On Natural gas we ony require LESS than a 1/2 PSI but we do depend on volume on 1- Long runs
(developed lenth) and 2- BTU demand in Cu FT Per Hr. Dont get water and gas piping confused.
Think like a mechanic seeing the severe restriction someone installed with the choking down of
size. Have fun
