Rachio Flow Meter Install 1" Copper

Seeing other “in the wild” flow meter installations was helpful to me in the planning stages so in the interest of sharing wanted to include my experiences. In my case there was not a clear shot of straight pipe, above ground, after the backflow valve and before the 90 elbow to the valve box.

Additionally, in reading some of the flow measurement research, it seemed that slightly longer straight pipe before and after the flow meter improved measurement accuracy. The consensus seemed to be 16" clear straight pipe before and 6" after. Since I needed to raise it either way, raised both sides of the back flow valve to create a 16" clear shot after the backflow valve and BEFORE the flow meter and 6" clear AFTER the flow meter and before the next 90 elbow.

The quality of the SharkBite fittings has been improving so used a combination of sweat and added sharkbite strategically to make replacing the flow meter or the backflow more plug and play in the future. Guess we will see how those SharkBite fittings hold up.

This is a bigger change so took about three hours to cut out the old sections and rebuild the new sections. There is definitely some cost involved whenever working with a copper installation.

As others have experienced during calibration, using a 2 minute run time seemed to be give each zone a better chance to stabilize, even with check valves on all of the individual spray bodies.

Looking forward to seeing how the additional GPM information improves both irrigation accuracy/efficiency and general system design/maintenance.



@whilger Fantastic install.

I really appreciate you reporting on your experience.

These are my new favorite posts :wink:


@whilger – your install looks great! I did a double take :slight_smile:

You need at least 6" of 1-inch pipe before the flow meter (more is always ok!), but there’s no requirements for 6" of 1-inch pipe after the flow meter. Let me know if we need to revise any documentation if there’s confusion.

Did you increase your calibration time from 1 minute to 2 minutes?

The Rachio flow meter instructions were clear. I read the straight pipe guidance from Rachio of 6" as a minimum length (let me know if that’s not a fair read). Its easy to understand why the shortest possible minimum length is helpful for a retrofit application. In my case, no chance to retrofit, so closer to a new install. With the opportunity to choose any length of straight pipe, went a little longer hoping to give Rachio every chance at a smooth flow.

After purchasing the flow meter in March, Rachio guidance was still being developed, so looked into some other liquid flow meter/sensor installation recommendations. It was clear that turbulence inside the pipe was the enemy of accurate measurement. In terms of straight pipe requirements, many were similar within a range. One example from CST was “a minimum of 10 pipe diameters of straight pipe upstream and 5 diameters of pipe downstream to minimize irregular flow profiles”. All of the guidance I read were more than 6" and since I needed to change the configuration in any case, had some flexibility to choose a longer straight pipe run on both sides of the flow meter.

For calibration, tried both 1 and 2 minute run times and 2 minutes gave the system plenty of time to get up to a constant pressure and volume.


@whilger, thanks for clarifying. Just wanted to make sure we didn’t mislead you at all in the installation.

#smoothflow :slight_smile: