Non-Invasive Industrial Flow Measurement | Measure What's Inside Without Going In
FlowT clamp-on ultrasonic flow meters read liquid flow from outside the pipe wall. No welding, no pipe cutting, no process shutdown. Factory-direct from Shenzhen with real-flow calibration at 5 points before every shipment.
Find Your Solution | What's Your Situation?
Most flow measurement projects hit one of three practical constraints. Pick the one that matches your project and we'll show you the right product, specs, and next step.
SITUATION 01
The pipe is already running. I can't cut it.
SITUATION 02
I need inline measurement for conductive liquids.
SITUATION 03
I need branded or custom-spec meters for my project.
Retrofit and non-invasive flow monitoring
The pipeline is already in service. Cutting it means a process shutdown, welding permits, pressure retesting, and bringing the system back online. For existing HVAC loops, large water mains, or process utility lines, that cost can easily exceed the value of the measurement itself.
Running system - any shutdown causes production or service disruption
Sanitary or corrosion-resistant pipe materials that can't be easily welded
Large-diameter pipe (DN300+) where inline flanged meters require civil works
Petrochemical or process site where pipe penetration requires hot work permits
Temporary flow survey - no permanent installation needed
Pharmaceutical utility lines where pipe modification triggers revalidation
Recommended Solutions | Clamp-On Ultrasonic Flow Meter
Sensors mount outside the pipe with stainless steel clamps. Acoustic signals pass through the pipe wall and through the liquid. No pipe cutting, no pressure loss, no direct contact with the medium. Works on most metallic and plastic pipe materials.
Pipe Size Range：DN15 – DN6000
Accuracy：±1% of reading
Liquid Temp：-30°C to 160°C
Output Signals：4–20mA / RS485
Pipe Materials：Steel, SS, Cast Iron, HDPE, CPVC
Install Time：15–45 min per sensor pa
Where FlowT Meters Are Used - And What Problem Each One Actually Solves
Every industry below has a specific installation constraint that generic product pages don't address. Here's what actually matters in each application.
HVAC & Building Energy
Can't drain or interrupt the chilled/hot water loop
Chilled water and hot water loops run continuously. Draining the system, modifying pipe, and rebalancing pressure can cost more than the meter itself. FlowT clamp-on sensors install in 20–30 minutes per sensor pair-no system drain, no rebalancing. Compatible with carbon steel, copper, and CPVC HVAC pipe. 4–20mA and RS485 outputs connect directly to BMS systems for energy sub-metering and tenant billing.
Municipal Water Treatment
DN300–DN1500 mains make inline meters impractical
On large water transmission mains, flanged inline meters require civil works, additional pipe supports, and often temporary bypass piping. Clamp-on eliminates all of that-sensor pairs mount externally regardless of pipe diameter. Works on ductile iron, steel, and HDPE mains with or without cement-mortar lining (lining thickness compensation required-confirm with FlowT before ordering).
Power Plants
Cooling water circuits run on continuous operational schedules
Cooling water, circulating water, and makeup water pipelines in thermal and hydro facilities operate around planned maintenance cycles. Any inline meter installation needs a scheduled shutdown-often months in advance. External clamp-on measurement adds large-pipe cooling water monitoring to existing systems with no pressure loss, no added resistance, and no impact on system operation.
Food & Beverage
Sanitary stainless pipe modification triggers hygiene re-validation
For utility water, purified water, and CIP lines, any pipe modification can require a hygiene validation review. FlowT clamp-on meters install on the outside of the stainless pipe-no liquid contact, no pipe cutting, no impact on food safety certification. Note: for direct product flow lines, a hygienic inline meter is required. FlowT clamp-on suits utility water and CIP circuit monitoring.
Oil & Petrochemical
Pipe penetration requires hot work permits - weeks of approval time
On petrochemical sites, any cutting or welding on liquid process utility lines involves hot work permits, purging procedures, and safety inspections. That approval process alone can delay a project by 4–6 weeks. External clamp-on measurement avoids all pipe penetration-no hot work permit required. Suitable for cooling water, demineralized water, and non-hazardous liquid utility lines.
Pharmaceutical
Changes to utility pipe in validated systems may trigger partial revalidation
In pharmaceutical facilities, adding instrumentation to utility water piping can require documentation updates and partial revalidation of the affected system. Non-invasive clamp-on measurement on purified water (PW), cooling water, and WFI support lines avoids any pipe modification, keeping the validated system boundary intact while providing reliable flow data for process monitoring.
Which Technology Fits Your Working Condition?
The honest answer to the question most customers eventually ask. FlowT supplies clamp-on ultrasonic and electromagnetic meters. Here's when each one is the right choice - and when it isn't.
| Working Condition | Clamp-On Ultrasonic | Electromagnetic | Vortex / Turbine |
|---|---|---|---|
| Cannot cut the pipe (retrofit)Existing system, no shutdown available | ✓ Yes | ✗ No | ✗ No |
| Non-conductive liquidOils, hydrocarbons, deionized water | ✓ Yes | ✗ Not compatible | ✓ Yes |
| Conductive liquid (water, wastewater)Conductivity ≥ 20 µS/cm | ✓ Yes | ✓ Yes - higher accuracy | ✗ No |
| Liquid with suspended solids or air bubbles> 2% solids content, wastewater sludge | ⚠ Limited - signal may degrade with solids | ✓ Yes - handles solids well | ✗ No |
| Very large pipe (DN300+)Cost of flanged inline meters becomes significant | ✓ Cost-effective at any diameter | ⚠ Possible but expensive | ✗ Impractical |
| Small pipe (DN6–DN15)Limited pipe wall for clamp-on signal | ⚠ Challenging - verify with FlowT team | ✓ Yes | ✓ Yes |
| Zero pressure drop requiredCritical low-pressure or gravity-fed systems | ✓ Zero - external measurement only | ✗ Minor drop from lining | ✗ Significant drop |
| Accuracy for billing / custody transferCertified ±0.5% or better required | ⚠ Typically ±1% - may not qualify | ✓ ±0.3–0.5% with in-situ calibration | ⚠ Depends on installation |
| OEM / bulk project supplyPrivate label, framework orders | ✓ Yes | ✓ Yes | ✓ Yes |
| Unsure which row applies to your project? Send the pipe material, size, liquid type, and conductivity to joe@flowt.com.cn - we'll give a straight answer, not a brochure. | |||
How a FlowT order actually works
Every meter ships with factory calibration data. Here's what happens between your first inquiry and the meter going online at your site.
Technical Review
Send pipe size, material, liquid type, flow range, temperature, pressure, and output signal requirements. FlowT's team reviews and recommends the specific model and transducer configuration - not just a catalog page.
01
Quotation & Spec Sheet
You receive a clear quote with model number, configuration, calibration scope, delivery lead time, and warranty terms. Factory-direct pricing - no separate trading company markup.
02
Factory Calibration
Before shipment, each meter runs on a real-flow calibration rig at 5 flow points. Each point is tested up to 3 times to verify measurement stability. You receive actual measured data, not a type certificate.
03
Shipment & Documents
The meter ships with installation guide, wiring diagram, operation manual, and calibration certificate. Air or sea freight from Shenzhen to your destination - lead time confirmed at quotation stage.
04
Commissioning Support
FlowT provides online video guidance for clamp-on sensor positioning, wiring, and parameter setup. 12-month warranty covers confirmed product quality issues - free replacement, not repair-and-return delays.
05
How specific problems were actually resolved
Real projects, real installation constraints, and what FlowT supplied to resolve them. Pipe sizes, materials, and limitations included.
Beverage Bottling Plant - Purified Water & CIP Line Flow Monitoring
A beverage bottling plant in Bangkok needed flow measurement on purified water and CIP-circuit water lines. The existing 316L stainless steel sanitary pipes couldn't be cut-welding food-grade stainless requires re-polishing, passivation, and pressure retesting, followed by CIP re-validation of the affected circuit. Any shutdown of the water lines also disrupted production scheduling for the bottling line.
Pipe material：316L stainless steel, sanitary grade
Liquid：Purified water, CIP cleaning water
Primary constraint：No pipe modification - food hygiene certification
Output required：4–20mA to SCADA panel
FlowT solution: Fixed clamp-on ultrasonic flow meters installed externally on the stainless pipe. Sensors positioned downstream of adequate straight pipe run, clamped with stainless straps - no pipe modification of any kind. Installation completed during a short production break with no pipe work. Real-flow calibration certificate provided before shipment. Flow data connected directly to existing SCADA via 4–20mA signal.
High-Rise Commercial Building - Chilled Water Energy Sub-Metering
A commercial high-rise project in Dubai needed energy sub-metering on its chilled water distribution system across 14 riser locations, covering pipe sizes from DN80 to DN300. The HVAC system was already commissioned and running in an occupied building. Installing inline flow meters would require draining the chilled water loop floor by floor, working in occupied building risers, and rebalancing the system after each modification.
Pipe material：Carbon steel, pre-insulated
Liquid：Chilled water, 6–12°C supply
Pipe sizes：DN80 to DN300 across 14 points
Purpose：Energy sub-metering, tenant billing
FlowT solution: Wall-mounted clamp-on ultrasonic flow meters installed on the existing carbon steel pipe after removing insulation locally at each sensor location. No system drain, no pipe modification, no rebalancing required. 4–20mA and RS485 outputs connected to the building BMS at each floor. Each of the 14 meters was individually calibrated at the factory before shipment. The MEP contractor completed all 14 installation points in two working days without interrupting chilled water supply to the building.
Petrochemical Utility - Cooling Water & DM Water Flow Monitoring
A petrochemical facility in Johor needed flow monitoring on cooling water (DN250) and demineralized water (DN150) utility lines. Site safety policy required hot work permits for any pipe cutting or welding within the restricted process area - a permit approval process that typically takes 4–6 weeks. The project commissioning timeline couldn't accommodate that delay.
Pipe material：Carbon steel, insulated
Liquid：Cooling water, demineralized water
Primary constraint：Hot work permit - 6 week approval timeline
Pipe sizes：DN150 and DN250
FlowT solution: External clamp-on ultrasonic flow meters avoided all pipe penetration - no cutting, no welding, no hot work permit required. Sensors clamped onto the existing pipe after brief local insulation removal at each measurement point. Both lines installed in one day each, within the project commissioning schedule. Calibration certificate issued before shipment. FlowT provided online video guidance to the site team for sensor positioning, spacing calculation, and wiring.
What's behind the price and the delivery
Factory-direct pricing removes the trading company layer that sits between most buyers and the factory - no markup, no message relay, no delays when you need a technical answer.
5-pt
Real-flow calibration - not lab simulation. 5 flow points, tested up to 3 times each, with measured data on the certificate.
20+
Years in flow measurement, including 10+ years focused specifically on ultrasonic technology and clamp-on applications.
DN6–DN6000
Pipe size coverage across the full product range. Clamp-on sensors for large mains where inline is impractical or prohibitive.
12-mo
Warranty with free replacement for confirmed product quality issues - not limited to manufacturing defect under narrow conditions.
Factory-Direct Supply
FlowT manufactures and supplies directly - no separate trading company handling your order. This removes one layer of markup and one layer of communication delay. Technical questions go to the factory engineering team, not a sales intermediary.
In-House Quality Control
Key components, production steps, and final inspection are handled in-house. Real-flow calibration runs on a calibration rig - not derived from catalog specifications. You receive the actual measured calibration data for the specific unit you're receiving.
Application-Based Selection
FlowT doesn't just send you a catalog link. Send the pipe material, liquid type, conductivity, and installation constraints - the engineering team will tell you what will work and what won't, and why. If a clamp-on meter isn't suitable for your pipe condition, they'll say so directly.
FAQ
Q: Does clamp-on ultrasonic work on all pipe materials?
A: Transit-time clamp-on measurement works on most metallic and plastic pipe materials: carbon steel, stainless steel, cast iron, ductile iron, copper, HDPE, CPVC, and PVC. The requirement is that the pipe wall transmits acoustic signals with sufficient strength. Heavily corroded pipes, pipes with thick bituminous or tar coating on the outside, or pipes with thick internal scale layers can reduce signal quality. Pipes with thick cement-mortar lining (such as large water mains) can work but require lining thickness compensation in the setup - confirm the lining specification with FlowT before ordering. Concrete pipes without a steel or plastic shell are generally not compatible.
Q: What accuracy should I expect?
A: For clean, single-phase liquids in straight pipe with adequate upstream and downstream straight run - typically 10× pipe diameter upstream, 5× downstream, clear of elbows, pumps, and valves - transit-time clamp-on meters achieve ±1% of reading. Accuracy is affected by pipe condition, liquid cleanliness, pipe geometry, and installation alignment. If your project requires better than ±1% - for billing-grade or custody transfer applications - an electromagnetic meter installed inline in a controlled straight-run section will typically achieve ±0.3–0.5%. FlowT will tell you which technology fits your accuracy requirement when you send the project details.
Q: How much straight pipe run is needed before and after the sensor?
A: The standard guideline is 10× pipe diameter upstream and 5× downstream - clear of elbows, reducers, valves, pump outlets, and tees. Many real installation sites can't provide ideal conditions. Reduced straight run is possible in some cases but may affect measured accuracy. If your installation space is constrained, specify the available upstream and downstream distances when you send your inquiry. The FlowT team will advise whether a modified installation method - such as a different transducer spacing mode or angled measurement - can work within your site constraints.
Q: What's actually in the calibration certificate?
A: FlowT's calibration covers 5 flow rate points across the operating range of the meter. At each point, the measurement is repeated up to 3 times and the individual readings are recorded. The certificate documents the reference flow rates on the calibration rig, the meter's indicated values, the error percentage at each test point, and the calibration date. This is measured data from the specific unit you're receiving - not a type-approval certificate issued for the product model in general. If you need the certificate in a specific format for your project records, discuss that at the quotation stage.
Q: Can I order one sample unit before committing to a larger quantity?
A: Yes. FlowT accepts single-unit sample orders so you can test the product against your specific installation before placing a larger order. Sample units ship with the same factory calibration and documentation as production orders. Sample lead time and unit pricing should be discussed directly with the FlowT team before ordering, as these depend on the product model and current production schedule.
Q: What communication outputs and protocols are available?
A: Standard outputs on most FlowT meters include 4–20 mA analog current loop and RS485 serial (Modbus RTU). Pulse output is also available on most models. HART and PROFIBUS are available on select models or as part of an ODM configuration. If your system integration or BMS requires a specific protocol - or a non-standard combination of outputs - include that requirement in your initial technical inquiry and FlowT will confirm availability before quoting.
Q: What if the liquid has suspended solids or air bubbles?
A: Transit-time ultrasonic measurement relies on a clean acoustic signal path through the liquid. Suspended solids, entrained air, or high particle loading scatter and attenuate the ultrasonic signal, which can cause unstable readings or signal loss. As a rough guideline, clamp-on ultrasonic is practical up to around 2% solids content for most liquids; above that, an electromagnetic flow meter is more appropriate. If you're unsure about your liquid composition, describe the medium when you inquire and FlowT will advise whether ultrasonic measurement is viable for your condition.
Q: How does after-sales support work?
A: FlowT provides online video guidance for clamp-on sensor positioning, wiring, and parameter setup after delivery. Each meter comes with a 12-month warranty. If a confirmed product quality issue occurs within the warranty period, free replacement support is provided - not repair-and-return. For installation or commissioning questions, contact the FlowT team directly at joe@flowt.com.cn or via WhatsApp at +86 150 7238 7442.