# friction loss formula



## BOBBYTUCSON (Feb 8, 2013)

Stupid question but is there a different calculus formula for figuring out head loss or friction loss in fittings? Copper specifically? Or is it the same formula I've been using for normal circumstances minus interval fullport ball valves and such by normal factors such as length of run , psi and I.d., I just want to make sure I'm not forgetting if fittings lik 90º's and such don't count for more friction.I'm pretty sure I'm gonna reccomend the city install a 1" service meter for my customers custom home about to be built.was thinking 3/4 but after seeing plans, he's got way more fixture units than 3/4 can handle especially for guest house with almost as many units as main house lol.home is gonna be sick! Guy is loaded, there's three wet bar lavatorys alone in the pool area.


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## Michaelcookplum (May 1, 2011)

Not sure about your answer but id suggest a 1" line


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## BOBBYTUCSON (Feb 8, 2013)

Yah I'm staying with my gut instict aswell.I definitely remember formula for sizing pipe for new instalations and factoring in all the nessisary dictating variables, but I remember in the back of my memory either I read it somewhere or a master plumber mentioned a factor for formulating fittings since they add friction loss themselves aswell on top of the already factored length of run and pipe material and all that stuff.I just can't remember the formula for fittings as strait runs are to themselves.fittings add turns and change of direction that causes changes in pressure and friction loss.this is really stumping me


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## crown36 (May 21, 2013)

BOBBYTUCSON said:


> Stupid question but is there a different calculus formula for figuring out head loss or friction loss in fittings? Copper specifically? Or is it the same formula I've been using for normal circumstances minus interval fullport ball valves and such by normal factors such as length of run , psi and I.d., I just want to make sure I'm not forgetting if fittings lik 90º's and such don't count for more friction.I'm pretty sure I'm gonna reccomend the city install a 1" service meter for my customers custom home about to be built.was thinking 3/4 but after seeing plans, he's got way more fixture units than 3/4 can handle especially for guest house with almost as many units as main house lol.home is gonna be sick! Guy is loaded, there's three wet bar lavatorys alone in the pool area.


If you're under IPC, you may be able to find the formula and charts in the Appendix Section, for sizing the water piping system.


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