How do i determine the friction losses for a reduction in pipe diamete
How do i determine the friction losses for a reduction in pipe diamete
(OP)
I am pumping wastewater from an aerobic tank to a membrane tank at a flow rate of 200gpm. The inlet piping to the pump is 4" SCH 80 PVC and the outlet is 3" SCH 80 PVC. The inlet to the membrane tank reduces down to 2" so I need to determine what losses i will see by going down to 2".
Any insight is appreciated.
Any insight is appreciated.





RE: How do i determine the friction losses for a reduction in pipe diamete
RE: How do i determine the friction losses for a reduction in pipe diamete
For a Reducer,
Head loss, Hf = (1/Cc - 1)^2 * V2^2 / 2 / g
where,
Cc = 0.582 + 0.0418/(1.1-D2/D1)
D1 = upstream inside diameter
D2 = downstream inside diameter
V2 = downstream fluid velocity
g = acceleration due to gravity
For an Expander, divide the above Hf by 0.7
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RE: How do i determine the friction losses for a reduction in pipe diamete
The losses in sharp reducers occur downsteam of the vena contracta where the flow expands and the positive pressure gradient exists.
RE: How do i determine the friction losses for a reduction in pipe diamete
RE: How do i determine the friction losses for a reduction in pipe diamete
Are there more answers to this problem than #2?
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RE: How do i determine the friction losses for a reduction in pipe diamete
RE: How do i determine the friction losses for a reduction in pipe diamete
If you solve the formula.... its pretty obvious the pressure loss across his reducer is about 1 psi, that's all there is to this.
http://virtualpipeline.spaces.msn.com
RE: How do i determine the friction losses for a reduction in pipe diamete
RE: How do i determine the friction losses for a reduction in pipe diamete
http://virtualpipeline.spaces.msn.com
RE: How do i determine the friction losses for a reduction in pipe diamete
http://virtualpipeline.spaces.msn.com
RE: How do i determine the friction losses for a reduction in pipe diamete
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: How do i determine the friction losses for a reduction in pipe diamete
This formula is for fast flow, which is usually better for me. They also give another group of table based coefficients for slow flows, but I don't like programming table lookup and interpolation functions and the previous is conservative for slow flows. And after all its only 1 psi. OK I grant you its a bigger number in kPa (6.89 kPa)
http://virtualpipeline.spaces.msn.com