3/4" to 1" on 100 ft main line to the house

[Brad Littlejohn]

I am replacing p0ly B with PEX. Starting to replace my line between the meter and the house first. I found out that the main line is 3/4" ish almost 1". It is old black plastic pipe. It uses barb fittings. There is a hugh difference in diameter from the old 3/4" to the new PEX 3/4". With that said, would it be correct to upgrade the main line from the house to the water meter to 1" PEX to maintain the same static pressure? The water meter is 3/4" will a larger pipe through off a meter reading?

Thanks,

Brad

 

[wwhitney]

Larger pipes are basically always better. The pipe size doesn't change static pressure (when no water is running), but a larger pipe would cause less pressure loss due to friction during flow. No problem using 1" PEX on a 3/4" meter, and I would think that would be the minimum size to consider. If you look for similar threads, Terry has a nice chart he posts showing suggested lateral size based on distance and demand at the house.

Cheers, Wayne

 

[Sponsor]

 

[Terry]

For copper or poly pipe,
not PEX

For PEX pipe sizing.

 

[Reach4]

I am replacing p0ly B with Pex. Starting to replace my line between the meter and the house first. I found out that the main line is 3/4" ish almost 1".

What makes you think the old line is polybutylene rather than polyethylene? Pipe markings that say PB would be one way. It would be a shame if you replaced good polyethylene pipe needlessly. But if replacing, if longer than 100 ft, consider SIDR polyethylene; it's bigger for the same nominal size, and is cheaper. However the PEX is probably easier to connect.

Either way, snake the pipe in the trench, rather than pulling it tight.

 

[Brad Littlejohn]

Thanks folks!!!! They went with Poly B (the grey stuff ) a few feet from the house. So, I did not see the black stuff until I was into digging. It might have be worth saving but, PEX is so cheap ($70) for a 100 ft. And I had invested the time and effort digging. I did not want connections in the ground that could leak.