Friction head
Friction head
(OP)
Hi everyone. I wanna ask regarding friction head, why is it at total discharge head calculation the friction head is added while in total suction head calculation the friction head is subtracted?
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RE: Friction head
h1 be the total suction(static) head
h2 be the total discharge(static) head
hf1 be the friction head loss in the suction piping
hf2 be the friction head loss in the discharge piping
total head to be developed by the pump= h2+hf2-h1+hf1
RE: Friction head
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Friction head
Total Disch Head = hsd + hfd + hvd ± hpd
Where:
hsd = Discharge Static Head
hfd = Discharge Friction Head
hvd = Discharge Velocity Head
hpd = Discharge Pressure Head
Total Suction Head = hss – hfs + hvs ± hps
Where:
hss = Suction Static Head
hfs = Suction Friction Head
hvs = Suction Velocity Head
hps = Suction Pressure Head
Note that (-)hfs is negative while (+)hfd is positive. Why is it?
RE: Friction head
RE: Friction head
System head = total discharge head - total suction head
H = hd - hs
The total discharge head is made from three separate heads:
hd = hsd + hpd + hfd
- hd = total discharge head
- hsd = discharge static head
- hpd = discharge surface pressure head
- hfd = discharge friction head
The total suction head also consists of three separate headshs = hss + hps - hfs
hs
= total suction head
hss = suction static head
hps = suction surface pressure head
hfs = suction friction head
http://www.mcnallyinstitute.com/07-html/7-01.html
RE: Friction head
RE: Friction head