1. Piping systems

( 1 ) Closed circuits and open circuits

( 2 ) Two - pipe systems and four - pipe systems

( 3 ) Direct return systems and reverse return systems sm

( 4 ) Primary pump systems and secondary pump systems .

( 5 ) Constant flow systems and variable flow systems

2. Piping fittings

( 1 ) Expansion joints

( 2 ) Air vent valves

3. Selection of pumps

( 1 ) Types of pumps

( 2 ) Types of impellers

( 3 ) Shaft seals

( 4 ) Changes in pump performance

( 5 ) Typical performance curves

( 6 ) Cavitation

( 7 ) Allowable charge pressure ( allowable back pressure )

( 8 ) Surging

( 9 ) Key points when selecting pumps