670' residential water line. What size should I use

[OHIOresident]

I just talked to the water service department and they said that there is no monthly difference in billing price between the 1" and 1 1/2" meter. Just the inital cost of the meter is different. They also told me that the output side of the meter would have 70lbs of pressure. I guess there is a 5lb drop somewhere between the main, which is 75lbs, and the meter output, which is 70lbs. The Net elevation change is +38' from the meter to the shower valve on the second floor. From where the 1/2" copper comes off of the 3/4" copper feed line in my basement, There are 6 elbows in the 1/2" copper to the shower valve. I don't ever see a situation where I would run the shower head and rain head at the same time. I do think I will run the rain head and 4 body sprayers at the same time. Just me and my wife in the house, so there probably wont be a lot of other fixtures being used at the same time as the shower. Maybe a toilet flushing and a faucet to wash hands afterwards. Dishwasher is always run in the middle of the night while we are in bed. I hope this helps answer any questions still open. You guys are great. Thank you so much for all the help.

 

[Jadnashua]

With no flow, disregarding elevation changes, in a pressurized, closed system, the pressure is the same everywhere. It is only when there is flow do you start to have differences in the working pressure at various points along the path and use points.

 

[Sponsor]

 

[Runs with Bison]

How (as in what line size in the home) are you planning to feed that six head shower system? What are the individual body sprayers supposed to put out? The devil is in the details on that, because you will be taking a lot of DP if they add up to 12-15 gpm through a single 3/4" line in the home, and I doubt a 1/2" could supply all of them at once. What appear to be short runs add up, especially when you add equivalent lengths for tees, elbows, and such.

 

[Gator37]

Runs with Bison has a valid point. I looked up a specification on a rain shower head alone and it said 2.5GPM @80psi and 1/2" connection. OHIOresident check your notifications I sent you a note hope you can get it.
In my hast I said 58' head previously which should have been 38'. The "length" of the -20' drop only counts against the friction loss in the pipe.

 

[OHIOresident]

The rain shower head I picked out flows 2.5gpm/80psi/1/2" line. The body sprayers I picked out each flow 2.0 gpm/80psi/1/2" line. So, I guess the flow rate I need for the shower alone if nothing else in the house is being used and I have the rain head and body sprayers on is a total of 10.5gpm. The temp valve I am considering says it can flow 12gpm because it is a 3/4" valve hooked to 1/2" lines. It would flow 18gpm if I had 3/4" feed lines, but that isn't possible. Another thing is that these all seam to be rated at 80psi. Since I am not going to have 80psi, will they use less gpm than rated? All of this is still assuming that I go with the current recommendation of a 1" meter with a 1 1/2" water line to the house. Does anyone now think that I will need the 1 1/2" meter to provide enough gpm for my shower? Has anyone come up with a guess on what my psi will be at the shower valve based on all the variables provided? Thanks for all the advise. Steve

 

[Runs with Bison]

Shower head flow restrictors have pressure compensation devices in them--at least the ones I've fiddled with. Some work better than others, but they produce roughly a constant flowrate from 35-80 psig. Below that the flow begins to taper off. The problem I saw in some was that in the high end, 70-80 psig range, some were actually experiencing permanent deformation that was affecting the flow rate--reducing it substantially...a very counterintuitive result. The deformation was non-obvious. Keep in mind that 70 psig at the street or house is not the same as 70 psig at the shower head. There are elevation losses, dynamic (flow) line losses and shower valve losses that will drop it down some more.

It is difficult to pin a number on the pressure you will see at the shower valve. What we are really trying to do is make sure you are in a comfortable range that will allow someone to flush a toilet, etc. without noticeably impacting the shower flow. If you have 70 psig after the meter, the elevation difference you mention, and 1-1/2" line you should be in good shape, as long as the lines in the house to the bath are not undersized for the new shower arrangement. If the shower is on the upper floor then you have 16.5 psi of elevation loss from the meter (a constant.) At 10.5 gpm the 1-1/2" line will only lose about 3 psi due to the flow itself, maybe a pound more for fittings or bends. That would give you around 50 psi at the shower valve/valves without accounting for any dynamic (flow) pressure drop in the house lines. Note: If the shower is on the lower level of the home then the pressure available will be somewhat higher (0.433 psi per foot of elevation.)