Energy Management

Combined Metering and Energy Efficiency Optimization of Industrial Circulating Cooling Water Systems with Electromagnetic Flow Meters and Pressure Transmitters

Q: LGF-PA66 electromagnetic flow meter vs turbine flow meter: which one should I use for clean water?

Both meters handle clean conductive water, but their construction leads to very different field behavior. Turbine meters use an impeller in the flow path to generate pulses. They are accurate (±0.5%–±1.0%), but the rotor is a wearing part: particles, scale and rust can jam it, low flow may never overcome bearing friction (a dead start-up band), and the constriction creates permanent pressure loss. On raw water carrying algae or floc, turbine bearings typically last only 1–2 years. The LGF-PA66 electromagnetic flow meter has an unobstructed measurement tube with no moving parts — only the liner and electrodes touch the medium. It is immune to particles and fibers, pressure loss is near zero, turndown reaches 100:1, and accuracy holds at velocities down to 0.3 m/s, which matches the strong day/night flow swings of supply networks. The aviation-grade PA66 composite body is roughly 60% lighter than a stainless body of the same size, cannot corrode, and the IP68 design allows submerged pit installation. Turbine meter: small-bore (DN4–DN40) batching of oil products or ultra-pure water. LGF-PA66: DN15 and above for potable water, reclaimed water and industrial water — especially custody-transfer points and DMA district meters. For more details, please visit our product page or contact our technical team.

Q: How should I choose between the 0.2% and 0.5% accuracy versions of the LGF-PA66 electromagnetic flow meter?

The LGF-PA66 is produced in both ±0.2% and ±0.5% accuracy versions. The choice depends on what the flow data is used for — not on picking the highest number. ±0.5% version : for process monitoring, internal water balance in wastewater plants, industrial cooling-water assessment and most DMA district meters, where readings guide operations rather than invoices. Paired with an EC32 RTU uploading instantaneous flow and pressure for night-flow leakage analysis, it is fully sufficient — and saves a price tier. ±0.2% version : for custody transfer and billing (water sales between companies, heat-supply metering), quota-based assessment, and any point verified under JJG 1033, the Chinese verification regulation for electromagnetic flow meters. On large lines a 0.3% error translates into a substantial annual billing difference. Two engineering details matter in practice. Rated accuracy holds within the 0.3–5 m/s velocity window — if the line runs persistently below 0.5 m/s, downsize the meter to raise velocity, otherwise neither version performs. The ±0.2% version is also less tolerant of installation disturbances: keep at least 10D straight pipe upstream and 5D downstream, away from pump-outlet turbulence. The integral PA66 body with built-in grounding electrode closes the signal loop inside the meter, which is what keeps the zero stable at high turndown. Specify the accuracy grade at order time — the two versions differ in converter calibration and are not interchangeable in the field. For more details, please visit our product page or contact our technical team.

Q: How to configure the LGF-PA66 with an EC32 RTU for a DMA district metering point? Which communication protocols are supported?

The standard DMA district metering point is an LGF-PA66 magnetic flow meter plus an EC32 RTU plus minimum-night-flow analysis on the platform side. There are two wiring options: connect the LGF-PA66 RS485 port to the EC32 serial port over shielded twisted pair running Modbus RTU (default 9600bps, 8N1), or feed a 4-20mA analogue signal into an EC32 AI channel. For long cable runs prefer the digital link — better noise immunity, and it also exposes totaliser, empty-pipe alarms and other diagnostics. Configuration points: Addresses and registers : when several LGF-PA66 meters share one RS485 bus, assign each a distinct slave address, poll instantaneous and totalised flow registers, and verify the unit scaling factors. Acquisition strategy : set the EC32 to sample every minute and report every 15 minutes. The 2:00–4:00 minimum-night-flow window must never be skipped — it is the core input for leakage analysis. Connectivity : the EC32 supports 4G Cat.1 and NB-IoT. In underground valve chambers with weak signal, order the external-antenna version and route the antenna to the chamber mouth. On the platform, alarm thresholds are set against the baseline of minimum night flow, combined with district pressure data to locate leaking pipe sections. Meter sizes follow the district main — commonly DN80 to DN300 — with flange standards matched to the existing network. For more information, please visit our product pages or contact our technical team.

Q: Should an electromagnetic flow meter be installed on the pump suction or discharge side? LGF-PA66 siting in pump stations

Install it on the discharge side whenever possible. On the suction side the meter sits under vacuum, where cavitation and degassing cause erratic readings, the flow profile is disturbed by elbows and reducers, and sustained vacuum stresses the flange-to-body seal. The LGF-PA66 has an all-insulated composite body with no liner to debond, but the positive-pressure siting rule still applies. Siting checklist for pump stations: Straight run ≥5D upstream and ≥2D downstream; extend the upstream run if a reducer sits close; Avoid the highest point of the line (air pockets) and the lowest point (sediment); prefer a mid horizontal run or a vertical section with upward flow; Flooded valve pits require the IP68-rated version; the PA66 body weighs about half of a comparable stainless-steel meter, which matters when lowering it into a confined pit; With frequent pump cycling the PA66 body withstands water-hammer shocks well, and an EC32 RTU can alarm on flow transients to watch pump health. If suction-side mounting is unavoidable, confirm the pump runs flooded-suction and keep the meter as close to the pump inlet flange as possible to shorten the vacuum section. Check pipe supports before installation — vibration from the pump outlet travels into the meter body and affects long-term sealing. For more information, please visit our product pages or contact our technical team.

Q: What is the pressure loss of the LGF-PA66 electromagnetic flow meter and does it add pumping energy cost?

The LGF-PA66 has a full-bore straight-through measuring tube with no throttling elements and no moving parts. Pressure loss comes only from minor local resistance: a few kPa up to roughly a dozen kPa at rated flow across DN15–DN1200. Orifice plates typically cost 10–40 kPa and turbine meters are comparable or worse, so the electromagnetic design is the energy-saving choice. Two points for pumping-cost evaluations: The PA66 body is moulded in one piece with low surface roughness; at the same size and flow it loses slightly less head than a stainless-steel body with a separate liner; In pump-station retrofits this pressure-loss level barely shifts the system resistance curve, so the pump operating point and long-term electricity consumption stay effectively unchanged. Where energy KPIs matter, pair the LGF-PA66 with an EC60 RTU: it collects the meter's 4–20 mA or pulse output together with pump power data and computes specific energy (kWh per m³) for the platform, exposing high-consumption periods. On DN300+ lines, every kPa of head saved translates into thousands of kWh per year — the reason many municipal stations replace orifice metering with the LGF-PA66 during upgrades. For more information, please visit our product pages or contact our technical team.

Targeting the lack of flow metering, large pressure fluctuations, extensive energy consumption of circulating water pumps, unclear water balance and insufficient energy assessment data in industrial circulating cooling water systems, this solution deploys integral/split electromagnetic flow meters and pressure transmitters to build a combined supply-and-return metering network. Together with RTU/data acquisition platforms it enables synchronized multi-parameter acquisition of flow, pressure and temperature and variable-frequency interlocked control of circulating pumps, achieving flow metering accuracy of ±0.5%, pipeline pressure fluctuation within ±0.02 MPa, and 8%~15% reduction in comprehensive pump power consumption, providing a continuous and reliable metering data foundation for water and energy saving, water balance testing and energy management system certification.

Overview

Summary

Key Advantages

Integral/split electromagnetic flow meters: measurement unaffected by temperature, pressure, density or viscosity, turndown ratio above 1:100, accuracy ±0.5%, selectable liner and electrode materials for circulating water quality

Pressure transmitters: diffused silicon/ceramic piezoresistive sensing, accuracy 0.2%FS~0.5%FS, 4-20mA+HART/RS485 output, excellent long-term stability

Combined supply-and-return metering network: synchronized flow, pressure and temperature acquisition supporting temperature-rise energy analysis and network resistance diagnostics

RTU/data acquisition platform: Modbus RTU/TCP, 4G/NB-IoT/Ethernet reporting, store-and-forward, remote configuration and diagnostics

Variable-frequency pump interlock: PID control based on return water temperature and supply-return differential pressure, automatically adjusting pump speed to avoid high flow and small temperature rise

Water balance and concentration management: three-level metering of make-up, blowdown and circulation volumes guiding blowdown and dosing strategies

Challenges

Missing metering points in circulating water networks; circulation volume estimated from pump nameplates with deviations over 20%, leaving water balance tests without data support
Many pressure monitoring blind spots; delayed detection of pressure fluctuations destabilizes cooling supply and affects heat exchange of production units
Circulating pumps run at fixed frequency for long periods with high flow and small temperature rise, wasting electricity without quantitative assessment
Flow, pressure and temperature data scattered across local instruments with severe silos, preventing combined energy efficiency analysis and network diagnostics
Missing make-up water metering; cycles of concentration cannot be controlled, and blowdown and chemical consumption remain high

Results

Full-coverage metering on supply main, return main and major branches with ±0.5% accuracy, enabling continuous and traceable water balance data
Real-time online pressure monitoring at key nodes with fluctuations within ±0.02 MPa, significantly improving cooling supply stability
Variable-frequency interlocked pump control based on combined flow, pressure and temperature data reduces comprehensive pump power consumption by 8%~15%
Continuous metering of make-up and blowdown water keeps cycles of concentration stable at 3~5, saving over 10% water annually
Unified multi-parameter data platform provides the data foundation for energy assessment, network diagnostics and energy management system certification

Solution Details

Combined Metering and Energy Efficiency Optimization of Industrial Circulating Cooling Water Systems

Industrial circulating cooling water is the largest water consumer in water-intensive industries such as petrochemical, power, metallurgy and chemical engineering. The metering and pressure monitoring of circulating water systems directly affect cooling performance, equipment safety and operating energy consumption. This solution combines electromagnetic flow meters and pressure transmitters to deliver refined metering, energy efficiency optimization and digital management of industrial circulating cooling water systems.

The Challenges of Traditional Circulating Cooling Water Management

Under traditional management, circulating water networks generally suffer from missing metering points, improper instrument selection, pressure monitoring blind spots and severe data silos. These issues create significant operational and financial losses:

Circulation volume is estimated from pump nameplate data with deviations over 20%
Pressure fluctuations cannot be detected in time, destabilizing cooling supply
Pumps run at fixed frequency for long periods with high flow and small temperature rise, wasting electricity
Water balance tests lack continuous metering data, making water-saving potential impossible to quantify

How Electromagnetic Flow Meters and Pressure Transmitters Work Together

This solution uses electromagnetic flow meters and pressure transmitters as core sensing units, deploying a combined metering network on the supply main, return main, branch lines and cooling tower make-up points. Electromagnetic flow meters measure conductive liquids unaffected by temperature, pressure, density or viscosity, with a wide turndown ratio above 1:100, ideal for high-flow, variable-condition circulating water metering; pressure transmitters monitor key pipeline nodes in real time and, combined with flow data, enable network resistance analysis. All instruments connect via 4-20mA/RS485 to RTUs or data acquisition platforms, achieving synchronized acquisition, remote transmission and centralized monitoring of flow, pressure and temperature, and supporting variable-frequency constant-pressure/temperature-difference interlocked control of circulating pumps, ultimately realizing refined metering, energy efficiency optimization and digital management of circulating cooling water systems.

Key Product Features and Technical Specifications

Integral/split electromagnetic flow meters: measurement unaffected by temperature, pressure, density or viscosity, turndown ratio above 1:100, accuracy ±0.5%, selectable liner and electrode materials for circulating water quality
Pressure transmitters: diffused silicon/ceramic piezoresistive sensing, accuracy 0.2%FS~0.5%FS, 4-20mA+HART/RS485 output, excellent long-term stability
Combined supply-and-return metering network: synchronized flow, pressure and temperature acquisition supporting temperature-rise energy analysis and network resistance diagnostics
RTU/data acquisition platform: Modbus RTU/TCP, 4G/NB-IoT/Ethernet reporting, store-and-forward, remote configuration and diagnostics
Variable-frequency pump interlock: PID control based on return water temperature and supply-return differential pressure, automatically adjusting pump speed to avoid high flow and small temperature rise
Water balance and concentration management: three-level metering of make-up, blowdown and circulation volumes guiding blowdown and dosing strategies

Core Performance Data at a Glance

±0.5%

Electromagnetic Flow Meter Accuracy

>1:100

Turndown Ratio

0.2%FS~0.5%FS

Pressure Transmitter Accuracy

4-20mA / RS485

Signal Output

Modbus RTU/TCP

Communication Protocol

4G / NB-IoT / Ethernet

Remote Reporting Options

Application Scenarios for Circulating Cooling Water Metering

The combined metering and energy efficiency optimization solution is designed for water-intensive industries including petrochemical, power generation, metallurgy and chemical engineering. It is particularly suited to industrial circulating cooling water systems that require continuous flow and pressure monitoring, variable-frequency pump control, water balance analysis and digital management. By deploying electromagnetic flow meters and pressure transmitters across supply mains, return mains, branch lines and cooling tower make-up points, plant operators gain full visibility into cooling water network performance and can systematically reduce energy consumption and water waste.

? Reference Sources

Industrial circulating cooling water system metering and energy efficiency optimization practices
Electromagnetic flow meter and pressure transmitter technical specifications
RTU/data acquisition platform integration for industrial water systems

Approach

How we implement intelligence into your infrastructure step by step.

Site survey and metering point planning

Map the circulating water process (cooling tower - circulating pumps - supply main - process units - return main - cooling tower), determine metering points on supply/return mains, branches and make-up/blowdown lines, verify pipe diameters, flow ranges and pressure ratings, and complete instrument selection and installation design.

Instrument installation and signal integration

Install electromagnetic flow meters on supply/return mains and branches per upstream/downstream straight-pipe requirements, and pressure transmitters at pump outlets, key main-line nodes and cooling tower inlets; connect flow, pressure and temperature signals via 4-20mA or RS485 to RTU/acquisition cabinets with proper power supply, grounding and lightning protection.

Platform deployment and interlock configuration

Deploy the data acquisition and energy management platform, configure point registers, sampling rates and alarm thresholds; establish combined flow-pressure-temperature data models, configure variable-frequency interlocked control strategies for circulating pumps (return temperature + differential pressure PID), and complete water balance and concentration calculation models.

Commissioning and energy efficiency diagnostics

Run a 30-day commissioning period, verify the balance between metering data, pump power consumption and make-up volume; conduct network resistance analysis and energy diagnostics based on combined data, optimize pump combinations and variable-frequency control parameters, and deliver an energy efficiency report.

Long-term O&M and continuous optimization

Establish periodic instrument verification and data quality inspection routines; the platform automatically generates water balance reports, energy consumption reports and alarm work orders; dynamically adjust metering points and control strategies with process changes to support corporate water/energy saving targets and continuous improvement of the energy management system.

Recommended Hardware

Essential components for this solution.

View All Products

流量仪表

Split-Type Electromagnetic Flow Meter | IP68 ±0.5%

Ecolor's self-developed split-type electromagnetic flowmeter, made from aerospace-grade polymer mate...

流量仪表

LGF Integrated Electromagnetic Flowmeter

Ecolor's self-developed aerospace polymer material electromagnetic flowmeter is suitable for flow me...

Remote Terminal Unit

HERO V9-EC32 Hydrology RTU | Remote Terminal Unit

This product has the functions of remote data collection, control and communication. It can receive ...

How should I choose between the 0.2% and 0.5% accuracy versions of the LGF-PA66 electromagnetic flow meter?

How to configure the LGF-PA66 with an EC32 RTU for a DMA district metering point? Which communication protocols are supported?

Should an electromagnetic flow meter be installed on the pump suction or discharge side? LGF-PA66 siting in pump stations

What is the pressure loss of the LGF-PA66 electromagnetic flow meter and does it add pumping energy cost?

View all FAQs →

Ready to Optimize Your Business?

Contact us, and our professional team will provide customized solutions to help your business achieve digital transformation.

Get In Touch

Combined Metering and Energy Efficiency Optimization of Industrial Circulating Cooling Water Systems with Electromagnetic Flow Meters and Pressure Transmitters