View Full Version : PE Friction Loss?
JCsPlumbing
08-10-2008, 02:44 PM
I've looked in my books and online and cannot find a table or chart for friction loss in PE pipe. Any links would be appreciated.
Thanks.
J.C.
JCsPlumbing
08-10-2008, 02:52 PM
Maybe more info would help. Customer wants to bring water from a well about 450' away with an estimated 10' head pressure. Well pump at 5gpm. They'll connect an outside hosebibb and about 12 outside misters using .5gph each (estimated).
Thanks.
J.C.
drtyhands
08-10-2008, 02:59 PM
I've looked in my books and online and cannot find a table or chart for friction loss in PE pipe. Any links would be appreciated.
Thanks.
J.C.
All I've found so far in my UPC are the eight charts determining friction in pipes with interiors ranging from copper to smooth through rough.
JCsPlumbing
08-10-2008, 03:03 PM
What do you show for loss in smoothwalled at 40-60psi over 450'?
J.C.
toolaholic
08-10-2008, 03:17 PM
Why not call any well driller? This is their music, they're running this stuff every day.
I would think They'd be glad to help.
drtyhands
08-10-2008, 03:19 PM
Our timing is for Sh!t.
I just got sat back down and surrounded with comforts to watch olympic boob tube after putting the book back where it belongs.I'll look it up on my next piss stop in a couple few hours.
Ask Mark/Utah he's looking at it as we speak.
:)
JCsPlumbing
08-10-2008, 04:11 PM
Why not call any well driller? This is their music, they're running this stuff every day.
I would think They'd be glad to help.
Already did that. They recommended starting off with 2" pipe and reducing at the end point. I call BS that this is too large and you're going to end up with no pressure & air space in the pipe at 5gpm. I could be wrong but want to get all the info. I don't think anyone should have to do things twice. :D
J.C.
DuckButter
08-10-2008, 04:32 PM
Sometimes a question like this is easier to find on MFG websites...or you might find it on the plastic pipes website.
Plastics Pipe Institute (http://plasticpipe.org/index.html)
toolaholic
08-10-2008, 09:19 PM
My 2 cents . Ask the question on Terrys Loves well forum. Then Master will jump in ,If He ain't barred again! Sorry, I couldn't resist pullin Masters chain
stokefire7
08-10-2008, 09:51 PM
[B]I've been looking for some info on this subject myself.
wrench spinner
08-10-2008, 10:18 PM
I have some books in the office Ill post the chart tommorrow morning when i get in to work! JC if you want PM ALL the details and ill figure out whatever you need! either that or give me a call in the AM ill be in the office about 7:30ish
wrench spinner
08-11-2008, 08:44 AM
http://goulds.com/pdf/TTECHWP.pdf\\
PE is not on there but it is a great reference that you SHOULD have!! PE Hazen Sawyer coeefficient is 150 which means it is pretty much the same as HDPE which we use for storm design.
using 150 as its coefficient of friction:
f=4.52 Q ^1.85
C^1.85 d^4.87
where
f=friction loss (psi per ft)
Q=rate of flow (gpm)
C=Hazen Williams Coefficient
d=internal pipe diameter
So using the above to solve for f
f=4.52 5GPM ^1.85
150^1.85 x 1 ^4.87
f=.0084 PSI loss per foot of pipe,
so at 450 feet of pipe our loss will be 3.76 psi loss our flow shoud remain the same and that is assuming 1" pipe
now ignoring the hose bib, simply because that will eat up pretty much all of your flow rate if it is opened full bore the "tax" on the system is .1GPM assuming you are right about the misters at .5GPH each... your total flow is negligable at .1GPM though the pipe, anything larger than 1" is overkill you can probably even get away with less, if you have a 30-50 pressure swith your pressure at the hose bib with ALL the misters on for the sprinkler system will be 46.24 at best and 26.24 at worst, so you may want to swap out the pressure switch to a 40-60 which will yeaild 56.24 and 36.24 similiarly
JCsPlumbing
08-11-2008, 08:55 PM
So if I understand right, our flow would remain the same with about 4psi loss on both ends of the switch? (On/Off cycle)
Also, wouldn't larger volume pipe (2") with only 5gpm pump cause LOSS of pressure and erratic pumping?
Thanks.
J.C.
wrench spinner
08-11-2008, 09:28 PM
JC we are looking at less pressure loss, about 1 psi. I cant imagine much fluctuation as far as pump on and off because it is still a solid column of water and you still have bladder tank or atmospheric tank on the end, the 2" would be fine as well
JCsPlumbing
08-11-2008, 10:37 PM
Thanks. Don't want to beat this to death but I want to make sure I nail this for the future.
Is there any advantage to increasing the pipe size to-let's say- 2" for the the first 150', 1.5" for the next 150', 1" for the final 150'?
As opposed to running the whole length in 1"? :confused:
J.C.
wrench spinner
08-11-2008, 10:40 PM
you are looking at about a greater loss i believe because of the reduce fittings probably about 5 or 6 PSI loss Ill check the books in the morning if you would like but i would just run straight 1" pipe
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