PRM 2-20 GPM Water Rotameter Flow Meter, 1 Inch Female NPT Connection, Acrylic Body with PVC End Tails, 316 SS Plunger & Travel Rod, Viton Seals, Max Pressure 85 PSI, Max Temp 125°F, ±4% Accuracy

Product works as it should.

Works Great with my QT non pressurized flow center. I used PVC also ( ToolmanJohn's design with a few changes ) but took a coupling and added to the end of the 90 where it would be pushed onto the QT return pipe. Chucked up the coupling in the lathe and flared it a bit to make it easier to find the QT return pipe. It reads the same as a borrowed unit that was over $400. This is a valuable tool to adjust the flow to the proper rate.

I bought this item to use in a geothermal heating system to measure the gpm. The description did not state that this item will only work in a horizontal set up. I wish the description would have been more clear. Cost me $10 in shipping to return. Looks like a good product if you need a horizontal set up.

YES.. I bought this with the intention of building my own GSHP flow center tool. I have non pressurized QT flow center, and the tool for checking water flow costs over $400. With this PRM Flow meter, I was able to glue together some PVC and a coupling to make my very own flow tool. Works great and accurately reported true GPM flow rate, which I needed to do true diagnostics to my ground source heat pump system.

Perfect for setting up an open loop geothermal system. Cheap enough to just plumb in permanently and periodically check it when the system is running!

Best deal out there for this product

These worked great in a geothermal ground loop installation. It's critical to get your water flow set correctly to prevent premature compressor failure. This allows you to know exactly what the flow rate is for the unit. I addes the yellow lables shown in the photo.