The main supply to the house is being modified. Currently have a 3/4" meter, goes to 1" PVC for 200 feet to the house. Converts to 3/4 copper out of the ground, 3/4 ball valve, 3/4 pressure reducer, then into the house. I get over 140 psi out of the meter.

I want to create a simple manifold arrangement at the house. From the main, one branch will come off before the pressure reducer, with full flow valve, and go to a new fire sprinkler system in the garage. I also want a high flow hose bib for garden hose before the reducer (likely will have 2 of these). Then last branch is a valve then pressure reducer to house.

The total flow clearly gets limited by all the 3/4 fittings at the street. The 200 feet of 1" I suppose is to help reduce pressure drop. I was wondering if I upgraded the front end of this simple manifold design to use 1" copper as the 'main' pipe it would be of any benefit. I.e. start with 1" tube and fittings then each branch would end with 3/4. Else just leave it all at 3/4 all the way through. The extra cost of larger fittings is not an issue.

Opinion if going a bit bigger would be of any benefit? Thanks.

The pressure is not affected by pipe size but volume is. When you are talking pipe size you are also talking about friction loss. Normally speaking, the larger the pipe size, the more options you have at your piping branches. Using full port valves is also recommended to keep from losing volume. The greater the distance also affects volume. BUT to answer your question...yes, size matters.



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Thanks. I was leaning in that direction.