Flow rate to pressure calculation

February 23rd, 2022, 12:55 am

I feel like this should be a simple question to answer but hours of googling and I still can't find a simple way to convert my flow rate (1 gpm) through my hose (1/4" inner diameter) into pressure. Am I missing something here?

Purpose is to make sure my pressure is high enough for plumbed in pre-infusion up to 4 bars. I'm using a gauged valve and it says 20 psi but that seems low to me since my house was measured at 70 psi to the line I've tapped into, which is flowing at 1 gpm flow rate with the same sized plumbing line. Of course that 70 psi read could be wrong so I'm just trying to get a sanity check.

#2: Post by **Jeff** » February 23rd, 2022, 1:29 am

https://www.pipeflow.com/pipe-pressure- ... ction-loss is a good summary of "contemporary" work in finding solutions to that problem. At least as I understand the current state of the art, the "trick" is mainly finding the right friction coefficient to use. There are some online calculators as well. One*, for 5 mL/s (18 L/hr), Sch 80, NPS 1/8, 10 feet gives a pressure loss of around 0.1 psi. If I got that right, the pressure loss at these low flow rates (for pipe) is "not much".

* https://www.tlv.com/global/US/calculato ... iping.html