Meter and pipe size for multiple homes

[Sandy Paskins]

My husband and I recently purchased a small mobile home park in Tallahassee, Florida. The majority of the homes are small singlewides with 1 or 2 bathrooms. The road is 700 feet long with 8 homes evenly spaced on either side, all of them on septic. Right now there is 1 residential water meter (5/8") feeding a 1" water line running through out the park. Needless to say, the tenants have virtually no water pressure. My husband and I want to put in new water lines on both sides of the road, each servicing 8 houses. We need help determining the proper tap/meter size and pipe size for our new water mains. We are leaning toward 1.5" taps/meters feeding into 2" PVC pipes running down the road and feeding into each home's 1" piping. I have many questions, but my main one is about the water pressure differences between the first home and the last on each run. The first homes are only 30-40' from the main road where the meters would be. Then each home is spaced out approximately 90' with the furthest ones being roughly 700' away from the meters. Is a 1.5" meter sufficient? Is a 2" private water main sufficient? Is having that large of a meter/main going to cause issues for the first few homes on the line having too much pressure? Should the diameter of the private water main feeding all 8 homes remain constant, or change as it gets further down the road? I welcome your suggestions and expertise!

 

[Terry]

The chart below is how I size water systems.

The chart below is for PEX which has a smaller diameter.

Perhaps for each side of the road, a 1.5" meter and 2" water service.
Much of what happens with distance is friction loss.
This is pretty much assuming most of these are one bath homes, and a few two bath.

Maybe someone can find a chart for 700 feet.
To combat friction loss, using a larger line makes a big difference. The cost is in the digging, not the pipe.

 

[Sponsor]

 

[wwhitney]

Have you researched what requirements apply to this installation, as far as city, county or state codes? For example, the UPC has an appendix on mobile home parks, and while my state, California, has adopted the UPC, it didn't adopt that appendix, while Nevada did adopt the appendix. But the UPC does specify that the supply for each mobile home should designed for at least 12 fixture units. Which doesn't apply to you, as Florida uses the IPC.

Also, what is the static water pressure at your water meter (or really anywhere downstream, as long as you note the elevation of the measurement)? That's the pressure when no water is flowing. And what if any is the elevation variation along the 700' road?

Having a large meter/main is not going to cause any problems, no one's pressure will ever exceed the city's static pressure. If that static pressure is higher than 80 psi, the homes should have pressure regulating valves regardless of the pipe or meter size.

As far as reducing the pipe size as you get farther from the meter, the only upside would be to save money. If that is a significant consideration, then with the proper info on supply pressure and design demand at each unit, an allowable downsizing can be calculated. But there's no downside to keeping it full size the full 700'.

Cheers, Wayne

 

[Jeff H Young]

theoretically not much benefit to running over size to the last house either. I wouldn't likely run 2 inch all the way to the end but would compromise and not be going 1 inch either. mainly to save a few bucks though.
Wayne hit the nail on the head with the pressure basically if one house needs a regulator they all will. I'm assuming the elevation is flat as a pancake of course elevation matters.

 

[Terry]

I size from the furthest point and work backwards to the meter, using the chart to account for friction loss.

 

[Sandy Paskins]

Thank you everyone for your quick responses. I REALLY appreciate it. This is Florida, so there is no significant elevation change . The property is flat all the way to the end. I will find out from the city what their static pressure is so that I can know if the homes need pressure valves. But it sounds like there is agreement that our plan to use a 1.5" meter and a 2" main should give us the results we're looking for. The homes are a mix of 1 and 2 bath homes, and not all of them have dishwashers. We'll take inventory of what each home has so that we have an accurate count of the fixtures and will bump that up against charts provided above. Based on feedback, we might reduce the diameter of the main down to 1.5" inches toward the end of the road. Thank you very much

 

[James Henry]

https://codes.iccsafe.org/content/FPC2017/appendix-e-sizing-of-water-piping-system

https://codes.iccsafe.org/content/FRC2017/chapter-29-water-supply-and-distribution

https://codes.iccsafe.org/content/IRC2018/appendix-e-manufactured-housing-used-as-dwellings

Better to educate yourself than to have regrets.

 

[Jeff H Young]

I wouldnt assume any of those sizes yet . 16 homes dont want to guess . City might help you size it. What about fire hydrants ?
anything goes in a trailer park? Dont know if youve talked to them yet I would expect 7 or 800 ft away from street any place civilized would require fire protection.
my guess is there is some generic value given on trailers for fixture units otherwise one rolls out another moves in and your system could be undersized.
you might have to crack a book open on this