3/4" Water

What a great idea to have a pump turn on with the adjustable water flow through a pipe! However IT IS NOT A 3/4" PIPE THREAD as one would expect for a plumbing fixture. The thread o.d. is 1.028" and NOT tapered as pipe threads are. I was able to chase the 14 pitch threads (standard pipe thread pitch) with a 3/4" pipe die for the first three threads. The hex portion prevented me from chasing the threads further. Those three threads should now allow a normal pipe joint. To me it looks like the Chinese knock off didn't quite get it right (again!).

For all to know, this is not made for low volume flows, it takes considerable flow to actuate!

This flow switch works very well at pool plumbing. It's what I've been looking for. It's of good quality. It's really recommended.

I found this switch useful for anything over 1.5 gpm. Anything under that will not trigger the switch.

My purpose in getting this flow switch was to turn on and off a water sanitizing UV light. However I didn't know it would be such a poorly designed unit.The paddles that come with it were too wide at the top when unit is screwed into another adapter to convert it to regular USA pipe thread, so I had to grind down the top half on both sides of the paddle, to match the width of the bronze tongue it attaches to, so it wouldn't bind to start with or when it returned to starting point.Also, even adjusting the internal screw to maximum depth, this flow switch has a spring that is way too stiff to trip the switch, regardless of water pressure.I even adjusted our house water pressure valve to maximum, until water was spattering all over the sink when faucets were turned on. Even then, I had to help the switch just a little bit, for it to trip on.Finally I took this worthless thing apart and ground down a little over 1/3 of the diameter of the outer circumference of the spring and put it all back together. Now it works just fine with regular house water pressure, and still allows plenty of mechanism adjustment for switch to turn off.Wasted a whole day on this project, would have cost me a fortune if I had hired a plumber! Should have known better, not to get a Chinese product!