Here is the question I sent to Rachio Support
“ I know that at least 6” of 1” Pipe is required on the inlet side of the flow meter to prevent turbulence which will cause inaccurate readings.
Is there any similar length of 1” pipe required on the outlet side of the flow meter ?. I’m installing on 1” PVC Pipe and would like to use the SharkBite 1” PVC to 1” MPT fitting on the outlet side to reduce the overall length of the cutout necessary for installation ( the outlet side will connect to an elbow). “
Here is the response I received.
“ Thank you for contacting Rachio Customer Support. My name is Matthew and I would be happy to assist you.
We recommend 16" total of copper piping (14" minimum for PVC) when installing the flow meter, which allows for a similar amount of a buffer on both ends of the flow meter.
Please don’t hesitate to reach out if you have other questions, comments, or concerns as well.
As my calculations seemed to suggest that the answer was incorrect I sent this response
“ Now I’m confused. The instructions for installing the flow meter on 1”PVC say to identify a 14” section of straight pipe between the backflow device and the valve box. To mark the pipe 6” from the backflow side of the pipe and then 6-1/2” from that point towards the valve box. To then cut the pipe at both points removing the 6-1/2” piece of pipe. Since the marked section of pipe was only 14”, the part of the 14” section of pipe on the valve box side remaining after the 6-1/2” piece is removed is only 1-1/2” long. While this length of pipe is sufficient to accommodate the Orbit Push On Lock Fittings, this is definitely not a similar amount of buffer on the valve box side of the flow meter. “
I’ve not received a reply.
To have the same amount of buffer ( ie 6” ) on both sides of the flow meter you’d need an 18-1/2” Long section of pipe rather an the described 14” Long section of pipe.