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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.
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.
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.
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.
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.
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 station in Jakarta uses the 4-20 mA output to verify flow before chemical dosing starts. In Western Australia, mining camps use 316L models on dust suppression pump lines where bore water is abrasive.
Send us these details: fluid type, pipe size DN, normal flow and minimum flow in L/min, operating pressure bar, operating temperature °C, and output needed. State if the switch wires into a PLC or directly into a pump contactor. If the media is seawater, high chlorine, or acid dosing, tell us upfront. We will specify PVDF, PP, or 316L instead of PVC. Contact Silver Automation Instruments by phone at +86-25-68650347, by WhatsApp at +86-25-52155837, or by WeChat at +86 15365082610. Our export team handles orders for Southeast Asia, Oceania, Latin America, Africa, and the Middle East.
What is the difference between a Flowvis array and a standard water flow sensor switch?
A standard water flow sensor switch uses one paddle or one thermal probe. The Flowvis array uses multiple sensing points to capture the flow profile. It is for pool and pump safety loops where a single point can miss a split stream or low flow condition.
Can these switches be used in seawater swimming pools?
Yes. Select PVDF or 316L wetted parts and avoid brass. Seawater pools and salt chlorinated pools will attack brass and standard carbon steel parts quickly.
What flow range do I need for a pump safety monitor?
Match the switch set point to the minimum allowed flow of the pump, heater, or dosing skid. For many pool pumps this is between 20 and 60 L/min. We set the trip point 15 to 20 percent below normal flow to prevent false trips.
Which output should I choose for a pool PLC or pump starter?
Choose a relay output rated 5 A for direct pump contactor wiring. Choose 4-20 mA or pulse output when a PLC or SCADA system already controls the loop and needs continuous flow data.
Can the switch be installed outdoors in hot climates?
Yes. Use a model with an IP65 or IP67 junction box and UV-stabilized cable. PVC bodies are fine up to 60 °C. For higher ambient or fluid temperatures, choose 316L or PP.
