Chilled water piping calculations

[tikitime]

When you are sizing your chilled water piping and pump, do you typically include the pressure drop for such items as the suction diffuser, flex connections, air separator, etc. or are you mainly concerned with the coil, fittings, valves and such? In all the examples I've seen, only the main components were included.

Thanks for your help!

 

[lilliput1]

You include all of them plus some more for safety and for future expansion. You also put in aging allowance for piping friction loss about equal to 15% for closed systems. About 60% for open systems. Also for open systems you must add the static head hight of the liquid highest level above the level of the water in the suction.
You select the pump with the capability of going to a larger impeller in the future. You select the pump motor hp such that the motor will not be overloaded as the pump ride its pump curve. If you specify a pump with inadequate capacity you will be responsible to have it removed & replace with one that works!