Is there a benefit to 1.25” porting when main water line is 1”?

[SHVA]

Main water line 1” in house would make Fleck 5810 aligned by spec alone.

However, my chemical engineering background says the resin column will slow rate of water flow if the in and out diameters are the same. So, in theory, making the outflow tract (porting of soft water up the column, after resin contact) with a larger diameter should reduce the pressure increase over the resin column and reduce the drop in flow rate.

True?

In practice:
Would having one size up on the valve (connecting a 1” water main to a 1 1/4” porting system, meaning Fleck 5812) reduce pressure and increase flow in the resin?

 

[ditttohead]

Sort of, there is a point of diminishing return. You will hit that with the 5810 vs 5812 on a smaller tank. The flow restriction is going to be more of the resin/media than the valve.

If you want the 5812, get it, there is absolutely no disadvantage other than the slightly higher cost. The advantage would be very minimal and likely undetectable. That being said, my main line is 3/4", I increased most of my plumbing to 1", and my system is the 5812. This was coming from the 7000 valve, a Clack WS1 before that, a 2510 before that , and a 5000 before that, and a 5600 before that, and a 4650 before that, and a 3600 https://docs.wixstatic.com/ugd/a3c37f_bec6ef82a50644a1be4fa665c54d8028.pdf before that.

In all reality, I have never noticed any difference. Other than greater efficiency and the "Wow" factors of the new valves but my house is only a 2 bathroom house. larger houses will have a lower potential of pressure loss during heavy use times with larger valves/systems.