In reply to message posted by kook:
…ummmmmm, I guess I was just looking for a simple “ballpark” answer. I am replacing 450′ of 3/4″ pipe with either 1.25″ or 1.5″ pipe – I dunno the type – it’s what people here in the US call “black poly” – you can find it at Home Depot, etc… The inner surface finish of all pipes is the same – same material, vendor, etc…
See the Above posting?
I thought you said 3/4″ 1.25 or 1.5 so I gave you a ball park number BUT I was conservative in my GPM flow.
The problem is you will have to know the exact or close to exact demand as you have to be careful of velocity especially in metal piping systems.
Today a guy puts in a pipe cause that was the way the other guy did it.
You also stated your running a 1/2″ pipe to the faucet That is also a misconception as it you look at the speedy riser or the actual faucet connection you will find the flow rate through the faucet seat is a lot less then the 1/2″ or even 3/8 supply.
Taking into consideration an aerator maybe installed you just reduced your actual even more and if you have flow restrictors?
See why plummmin is slightly more complex then the average stumblebums know about or do not bother to take into consideration?
Ask the moron why they used a 1/2 Supply to a kitchen faucet and the idiot would say CAUSE THAT’S THE WAY I BE SHOWN not that they actually took time to think and learn something about the field they picked on top dabble in.
Now if someone asked me why I would run a 1/2″ line to the kitchen faucet area my answer would be.
1- There is always the possibility of a dishwasher OR 2 being installed and I would not like to have large fluctuations in the piping so I need 1/2 or even 3/4″ hot for a possible future
2- A 1/2 cold water line well that is in case someone wants to install an automatic ice maker or a separate water supply to filtered water or possibly a clothes washer may be also connected near the kitchen sink VOLUME is the reason I may opt for a 1/2″ line not because it was always done that way
Are we having fun yet?