Company Profile

Flowvis Arrays & Water Flow Sensor Switches: Integrated Pool and Pump Safety Monitors

Quick Answer: Flowvis array and water flow sensor switch products from Silver Instruments detect a loss of flow and send a relay or analog signal to stop pumps, heaters, and dosing skids. They cover DN15 to DN50 lines and flow ranges from 2 L/min to 150 L/min. Send us your pipe size DN, flow range L/min, pressure bar, and fluid type for a direct model selection.

What a Flowvis Array Does on a Pool or Pump Skid

Here is the thing. A single paddle flow switch can stick in the open position on a dirty pool line. The Flowvis array from Silver Instruments uses multiple sensing points in the pipe instead of one moving part. It checks the flow profile and trips a dry contact relay when flow drops below the set point. That relay can break the pump starter circuit. So a pump does not run dry and a heat pump does not overheat.

Most engineers skip this part on small pump skids. Then a blocked skimmer basket or a closed valve causes a dry run. We have seen this on customer sites in Vietnam, Saudi Arabia, and Mexico. The repair cost is usually higher than the price of a flow switch.

Water Flow Sensor Switch Types and Outputs

A paddle flow switch with an isolated reed contact is the common option for clean water. A thermal dispersion switch works better in low flow and slightly dirty water. The Flowvis array is used for pool and pump safety loops where a false trip is not accepted. Output options include SPST relay rated 5 A at 250 V AC, 24 V DC NPN or PNP pulse, and 4-20 mA analog for PLC or SCADA.

Choose a relay output when the switch must trip a pump contactor directly. Choose 4-20 mA when the site PLC needs continuous flow trending. Because these integrated pool and pump safety monitors combine flow detection with relay logic, they act faster than a standard flow meter with a separate transmitter.

Key Specifications and Model Pairing

Model FVA-15 suits DN15 pipes and small residential pool heaters. It has a PVC body, flow range 2 to 30 L/min, maximum pressure 6 bar, maximum temperature 60 °C, and relay or NPN output. Model FVA-25 suits DN25 recirculation loops and commercial pool pump skids. It has a brass or 316L body, flow range 5 to 80 L/min, maximum pressure 16 bar, maximum temperature 100 °C, and relay output. Model FVA-40 suits DN40 and DN50 lines for water parks, desalination washdown, and industrial cooling loops. It has a PVC, PP, or PVDF body, flow range 15 to 150 L/min, maximum pressure 10 bar, maximum temperature 80 °C, and relay plus 4-20 mA.

These are standard models. We also build custom set points. A pump safety monitor is not a flow meter with a display. It is a switch that acts fast when flow stops. For seawater or high chlorine pools, specify PVDF or 316L. For drinking water or food contact, specify NSF listed materials.

Installation Notes That Prevent False Alarms

Mount the sensor in a horizontal pipe run where the pipe is always full. Keep at least five pipe diameters of straight run after an elbow, valve, or pump discharge. For outdoor pool skids in Australia, Southeast Asia, and the Gulf, use a weatherproof enclosure and a cable gland rated IP65 or higher. Install a 200 micron strainer upstream if the water carries leaves, sand, or scale. Do not set the switch exactly at normal flow. Set it 15 to 20 percent below normal flow to avoid nuisance trips during pump ramp up.

Applications We See in Export Markets

A pump skid manufacturer in Ho Chi Minh City uses FVA-25 switches on every heat pump recirculation loop. The relay output is wired into the compressor control circuit. A hotel pool operator in Dubai uses FVA-40 with PVDF bodies for salt chlorinated water and high outdoor temperatures. A distributor in Chile keeps FVA-15 stock for residential pool heaters and small booster pumps. A wastewater lift stat