2″ x 2.5″ FlowVis® Flow Meter


This is the 2″ x 2.5″ FlowVis®, the most accurate and reliable flow meter on the market today. Readings remain accurate in any orientation or position in your water system, even elbow to elbow. Kona Labs is proud to have invented this unit and sell it at the cheapest price available online. The space-saving design measures in GPM and conveniently includes scales for key velocity points. This makes it optimal for calibrating a variable speed pump and ensuring you are efficiently getting the most out of your energy use.

FlowVis® is more than just a flow meter; it’s also a fully functioning check valve! Ingenious in concept and flawless in operation, FlowVis® is a revolution in reliable flow measurement.

97 in stock


FlowVis® provides a precise, easy-to-read flow rate. Knowing the flow enables your pump’s speed to be optimized and energy savings maximized. It also allows precise and repeatable valve positioning for perfect water feature operation.

FlowVis® is incredibly robust, and designed with 15+ year lifespan!
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FlowVis® is over 95% accurate across the entire product range, making it the most accurate flow meter designed specifically for pools, spas, fountains, and water features.

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FlowVis® is available as both a complete pre-assembled unit for 1.5″, 2″, 2.5″, 3″, & 4″, and also as a retrofit kit that installs to a pre-existing Jandy® or Praher® 1.5″, 2″, or 2.5″ check valve assembly.

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FlowVis® can be installed horizontally, vertically, or even upside-down, and within any proximity to other fittings with no effect on accuracy.

Technical Data
  • Pipe diameters: 1.5″, 2″, 2.5″, 3″, 4″
  • Warranty: 15-years on design life, 7-years on spring
  • Approvals: NSF 50 (FV-C, FV-3, FV-4, FV-C-S, FV-C-Saline models)
  • Power losses: <0.2% additional motor power over having no check valve
  • Average accuracy:
  • 97.9% between 10 – 90 GPM (1.5″ model)
  • 97.9% between 10 – 110 GPM (2″ & 2.5″ model)
  • 98.15% between 90 – 220 GPM (3″ model)
  • 98.7% between 160 – 300 GPM (4″ model)