Oval Wheel Meter OI Series

The Bopp & Reuther Oval Wheel Meter Series OI is a high-precision volumetric flow meter engineered for accurate flow and volume measurement of a wide range of liquid media — from liquefied gases, acids, and alkalis to solvents, polymers, and adhesives. Designed for performance, reliability, and adaptability, the OI series ensures consistent accuracy even under extreme temperature and pressure conditions.

Built with robust materials such as cast steel, grey cast iron, and stainless steel for pressure-bearing parts — and aluminum, brass, or cast iron for wetted components — the OI series combines strength with long-term durability. With a flow range of 8 to 1,000 l/min and accuracy up to ±0.1%, it delivers dependable results across diverse industrial environments.

The OI series also supports high- and low-temperature configurations, extending its operating range from −60 °C to +180 °C, and up to 300 mm or 400 mm extensions for thermal compensation. Its flameproof or intrinsically safe design ensures reliable measurement in hazardous areas, making it ideal for chemical, petrochemical, paint, and process industries that demand precision and safety.

Bopp & Reuther Oval Wheel Meter OI Series (Slide Bearing Type)

Bopp & Reuther Oval Wheel Meter OI Series (Ball Bearing Type)

Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI UST

Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI

Bopp & Reuther Oval Wheel Meter OI Series (Slide Bearing Type)

The Bopp & Reuther Oval Wheel Meter OI (Slide Bearing Type) is a single-case, high-accuracy volumetric flow meter designed for precise measurement of liquids across a broad range of viscosities and process conditions. With a measuring accuracy better than ±0.3%, optional HART® communication, and robust slide bearing technology, it ensures dependable performance in demanding industrial environments.

The Oval Wheel Meter OI (Slide Bearing Type) by Bopp & Reuther is a direct volumetric (positive displacement) meter engineered for precise flow and total volume measurement of liquids, whether thin, viscous, or chemically aggressive.

Its single-case design offers a compact footprint and high operational reliability, while the slide bearing system guarantees low friction, minimal wear, and extended service life — even under continuous use. The OI series delivers exceptional accuracy (< ±0.3%, optional < ±0.1%), ensuring precision in both process control and custody transfer applications.

The meter supports multiple signal output and display options, including pulse outputs (NAMUR, open collector), analog 4–20 mA, MODBUS, or mechanical and electronic displays. It can operate without auxiliary power in its basic form, or with 16–30 VDC / 230 VAC for digital configurations.

Designed for Zone 1 explosion-proof areas, it also offers up to 15-point linearization for optimized calibration and system integration. With no straight inlet or outlet pipe sections required and low pressure loss, the OI series delivers both installation flexibility and operational efficiency.

Technical Information

Parameter	Specification
Product Type	Direct volume meter (Single-Case design)
Application	Volume and flow measurement of liquids
Measuring Accuracy	< ±0.3% of measured value (optional < ±0.1%)
Explosion Protection	Zone 1 (Ex-approved)
Process Temperature	–60°C to +180°C
Process Pressure	Up to 40 bar
Housing Material	Stainless steel, cast steel, or cast iron
Wetted Parts	Stainless steel, cast steel, or cast iron
Power Supply	None (basic model), 16–30 VDC, or 230 VAC
Output / Display Options	Pulse output (NAMUR, open collector), 4–20 mA, MODBUS, mechanical or electronic totalizer, LC display
Process Connection	Flange according to DIN or ANSI standards
Special Features	Low pressure loss, no straight runs required, 15-point linearization, HART®-suitable slide bearing

Options

Output Types: NAMUR pulse, 4–20 mA analog, Modbus digital communication

Display Options: LC display with configurable parameters; mechanical single or double pointer totalizer

Power Configurations: 16–30 V DC, 230 V AC, or self-powered mechanical version

Calibration Feature: Up to 15-point linearization for precise correction and improved accuracy

Material Variants: Stainless steel, cast steel, or cast iron to suit process media

Applications

Oil & Gas: Accurate flow measurement of refined fuels, lubricants, and heating oils

Chemical Processing: Monitoring of acids, alkalis, and process chemicals

Power Generation: Fuel oil consumption monitoring in turbines and engines

Marine & Transport: Flow control for bunkering and ship fuel management

Industrial Plants: Process dosing and volume tracking for production liquids

Benefits

Superior Accuracy: < ±0.3% standard; < ±0.1% optional with calibration

Rugged Slide Bearing Design: Reduces wear and ensures long-term stability

Versatile Signal Outputs: Supports NAMUR, 4–20 mA, MODBUS, and mechanical indicators

Flexible Power Options: Operates without power or via 16–30 VDC / 230 VAC

No Straight Pipe Sections Needed: Compact and simple to install

Low Pressure Loss: Minimizes system resistance and energy use

Explosion-Proof Zone 1: Certified for hazardous process areas

Advanced Linearization: Up to 15-point correction for enhanced precision

Durable Construction: Resistant to harsh process fluids and temperature extremes

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Bopp & Reuther Oval Wheel Meter OI Series (Ball Bearing Type)

The Bopp & Reuther Oval Wheel Meter OI (Ball Bearing Type) is a precision-engineered, single-case positive displacement meter designed for accurate flow and volume measurement of liquids across a wide temperature range. Built entirely from stainless steel and featuring low-pressure-loss ball bearings, it delivers unmatched reliability, accuracy, and longevity in industrial applications.

The Oval Wheel Meter OI (Ball Bearing Type) from Bopp & Reuther is a direct volumetric flow meter designed for precise measurement of liquids, including oils, fuels, chemicals, and other process fluids.

Its single-case construction and ball bearing support ensure smooth rotation, minimal friction, and extended operational life — even under demanding flow conditions. With a measurement accuracy of ±0.3% (optional ±0.1%), it is ideal for both process monitoring and custody transfer operations.

The OI series combines mechanical simplicity with precision engineering, offering a low pressure drop and no requirement for straight inlet or outlet pipe sections, making it easy to install in compact pipelines. Built from stainless steel housing and wetted parts, the OI ball bearing variant guarantees corrosion resistance and suitability for a broad range of liquids and process environments.

Certified for Zone 1 explosion protection, the meter features NAMUR pulse output and an optional mechanical display, ensuring reliable data transmission for process control systems.

Technical Information

Parameter	Specification
Product Type	Direct volume meter (Single-Case design)
Application	Volume and flow measurement of liquids
Measuring Accuracy	±0.3% of measured value (optional ±0.1%)
Explosion Protection	Zone 1 (Ex-approved)
Process Temperature	–60°C to +180°C
Process Pressure	Up to 40 bar
Housing Material	Stainless steel
Wetted Parts	Stainless steel
Power Supply	NAMUR
Output / Display Options	Mechanical display, pulse output according to NAMUR
Process Connection	Flanges according to DIN or ANSI standards
Special Features	Low pressure loss, no inlet/outlet pipe sections required, ball bearing design for long service life

Options

Display Options: Mechanical totalizer or pointer display for local reading

Signal Output: NAMUR pulse signal for remote data transmission and monitoring

Custom Flange Connections: Available per DIN or ANSI standards

Calibration Options: Optional high-accuracy calibration (< ±0.1%)

Applications

Oil & Gas: Measurement of refined fuels, lubricants, and heating oils

Chemical Processing: Flow measurement of solvents, acids, and process chemicals

Marine Industry: Fuel and oil monitoring for shipboard systems

Energy & Power Plants: Process control and fluid management

Industrial Manufacturing: Volume tracking in production lines and batching systems

Benefits

High Measurement Accuracy: ±0.3% standard; optional ±0.1% for precision-critical applications

Durable All-Stainless-Steel Design: Corrosion-resistant and ideal for aggressive fluids

Reliable Ball Bearing System: Ensures smooth operation and long service life

Low Pressure Drop: Maintains stable system performance without flow restriction

Flexible Installation: No straight inlet or outlet pipe sections required

Explosion-Proof Safety: Zone 1 certified for hazardous area applications

Easy Integration: NAMUR pulse output for connection to control and monitoring systems

Maintenance-Free Operation: Designed for long-term reliability and minimal servicing

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Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI UST

The Bopp & Reuther Oval Wheel Meter SMALL-OI UST is a compact, single-case positive displacement flow meter designed for precise volume and flow measurement of liquids. With ±0.1% optional accuracy, digital LCD display, and HART® / 4–20 mA output, it delivers superior reliability, flexibility, and performance for modern process automation and precision dosing applications.

The Oval Wheel Meter SMALL-OI UST by Bopp & Reuther combines advanced electronic signal processing with proven mechanical precision, offering high-accuracy flow measurement for small to medium flow ranges.

Built with a single-case stainless-steel construction and electronic housing in aluminum or brass, the SMALL-OI UST ensures both robust durability and excellent corrosion resistance. It achieves measurement accuracy up to ±0.3% (optionally ±0.1%), making it ideal for critical liquid applications in chemical processing, fuel management, and industrial dosing systems.

The integrated LCD display provides instant local readout, while the 4–20 mA / HART® communication and NAMUR pulse output allow seamless integration into existing control systems. Its compact design eliminates the need for inlet or outlet pipe sections, ensuring easy installation in tight spaces without sacrificing precision.

Engineered for Zone 1 explosion-proof environments, this meter supports 10-point linearization, enhancing accuracy across the entire flow range — a hallmark of Bopp & Reuther’s metering excellence.

Technical Information

Parameter	Specification
Product Type	Direct volume meter (Single-Case design)
Application	Volume and flow measurement of liquids
Measuring Accuracy	±0.3% of measured value (optional ±0.1%)
Explosion Protection	Zone 1 (Ex-approved)
Process Temperature	–60 °C to +180 °C
Process Pressure	Up to 40 bar
Housing Material	Stainless steel, brass, aluminum (electronic housing)
Wetted Parts	Stainless steel, brass
Power Supply	24 V DC (2-wire technology)
Output / Display	4–20 mA / HART®, NAMUR pulse output, LCD display
Process Connection	Flange acc. to DIN or ANSI, pipe fitting (8 mm / 12 mm)
Special Features	Compact design, no straight-pipe requirement, 10-point linearization, high-precision signal output

Options

Output Configurations: 4–20 mA, HART®, NAMUR pulse output

Display Options: Integrated LCD for total flow and diagnostics

Mounting Styles: Flange or pipe fittings (8 mm / 12 mm) for flexible installation

Material Variants: Stainless steel, brass, or aluminum electronic housing

Calibration Enhancement: 10-point linearization for optimized accuracy

Applications

Chemical Processing: Precise dosing of solvents, acids, and additives

Oil & Gas: Measurement of fuels, lubricants, and hydraulic oils

Industrial Manufacturing: Flow control in production and blending systems

Energy & Power Plants: Monitoring of coolant and auxiliary fluids

Research & Testing Facilities: Laboratory-grade flow measurement and calibration setups

Benefits

Exceptional Accuracy: ±0.3% standard, ±0.1% optional for critical dosing and process control

Compact & Efficient Design: No inlet or outlet pipe sections required

Digital Connectivity: 4–20 mA / HART® and pulse outputs for advanced automation systems

Easy Integration: Suitable for DIN / ANSI flanges or direct pipe fittings

Durable Construction: Stainless-steel and brass build for chemical resistance and longevity

Explosion-Proof Operation: Certified for Zone 1 hazardous areas

Enhanced Calibration: 10-point linearization ensures accuracy across full flow range

Low Maintenance: Simple, robust, and reliable design with long service life

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Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI

The Bopp & Reuther Oval Wheel Meter SMALL-OI is a compact, high-accuracy positive displacement flow meter designed for precise volume and flow measurement of liquids. Featuring stainless steel and bronze construction, NAMUR pulse output, and no need for straight pipe sections, it ensures superior precision, durability, and efficiency in industrial and process applications.

The Oval Wheel Meter SMALL-OI by Bopp & Reuther is a direct volumetric measuring instrument engineered for accurate and repeatable measurement of liquid flow, even under varying process conditions.

With its single-case design, this compact flow meter offers easy installation, low pressure loss, and high measurement accuracy up to ±0.3% (optional ±0.1%).

Constructed from stainless steel housing with bronze measuring components, the SMALL-OI is built for reliability and corrosion resistance, making it suitable for a wide range of liquids such as fuels, oils, and process chemicals.

The meter operates mechanically or electronically, with output options ranging from mechanical indicator (Type R7) to NAMUR pulse signals for integration into automation and control systems.

Its Zone 1 explosion-proof approval, no inlet or outlet straight pipe requirement, and compact pipe or flange connections make it the ideal solution for tight installations and precision flow control applications.

Technical Information

Parameter	Specification
Product Type	Direct volume meter (Single-Case design)
Application	Volume and flow measurement of liquids
Measuring Accuracy	±0.3% of measured value (optional ±0.1%)
Explosion Protection	Zone 1 (Ex-approved)
Process Temperature	–60 °C to +180 °C
Process Pressure	Up to 40 bar
Housing Material	Stainless steel, brass, or aluminium (electronic housing)
Wetted Parts	Stainless steel, bronze (oval wheel meter)
Power Supply	None / NAMUR
Output / Display	None / pulse output (1- or 2-channel NAMUR) / mechanical indicator Type R7
Process Connection	Pipe fitting or flange (DIN / ANSI)
Special Features	Compact size, low pressure loss, no inlet/outlet pipe sections required

Options

Output Options: Mechanical indicator Type R7 or 1- / 2-channel NAMUR pulse output

Power Configuration: Operates mechanically or via NAMUR electronic output

Mounting Options: Pipe fittings or flanges per DIN / ANSI standards

Accuracy Upgrade: Optional ±0.1% high-precision calibration

Material Selection: Stainless steel or bronze for maximum compatibility with different liquids

Applications

Oil & Gas: Measurement of diesel, lubricants, and heating oils

Chemical Industry: Flow monitoring of solvents, acids, and process liquids

Power & Utilities: Cooling and fuel oil flow control

Marine Industry: Bunkering and onboard liquid monitoring systems

Manufacturing: Batch dosing and production line flow measurement

Benefits

High Accuracy: ±0.3% standard, ±0.1% optional for high-precision needs

Compact & Versatile: Ideal for confined installations or small pipelines

Durable Design: Stainless steel and bronze construction for chemical and thermal resistance

Flexible Output Options: Available with mechanical or NAMUR pulse outputs

Explosion-Proof: Zone 1 certified for hazardous area applications

No Straight Pipe Requirement: Simplifies installation and reduces space needs

Low Maintenance: Long service life with minimal moving-part wear

Reliable Operation: Consistent performance under variable temperature and pressure conditions

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Industries We Serve

Oval Wheel Meter OI Series

Bopp & Reuther Oval Wheel Meter OI Series (Slide Bearing Type)

Bopp & Reuther Oval Wheel Meter OI Series (Ball Bearing Type)

Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI UST

Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI

Bopp & Reuther Oval Wheel Meter OI Series (Slide Bearing Type)

Benefits

Bopp & Reuther Oval Wheel Meter OI Series (Ball Bearing Type)

Benefits

Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI UST

Benefits

Bopp & Reuther Oval Wheel Meter OI Series SMALL-OI

Benefits