KROHNE OPTISONIC 3400 Ultrasonic Flowmeter

Overview

The KROHNE OPTISONIC 3400 is a three-path ultrasonic inline flowmeter engineered for a wide range of standard and demanding liquid process applications, from homogeneous, non-viscous aqueous liquids to viscous fluids exceeding 1000 cSt. Its full-bore, completely welded construction contains no moving parts and creates no pressure loss, making the OPTISONIC 3400 a maintenance-free measurement solution across an exceptionally broad size range, from DN25 (1 in) for dosing duty to DN3000 (120 in) for large-diameter water transportation pipelines.

As the official authorized partner and exclusive regional representative for KROHNE, Seven Star LLC proudly supplies the OPTISONIC 3400 to process industries, water utilities, and marine operators throughout the Sultanate of Oman and the wider GCC. Every meter shipped carries full manufacturer warranty and the regional technical support that keeps custody-transfer and process flow measurement accurate and compliant.

Measurement Principle

The KROHNE OPTISONIC 3400 measures flow using the transit-time ultrasonic principle across three independent measuring paths. Ultrasonic pulses are transmitted diagonally across the pipe in both the upstream and downstream directions; because fluid flow speeds up the pulse traveling with the flow and slows the pulse traveling against it, the resulting transit-time difference is directly proportional to the flow velocity. Averaging the signal across three paths compensates for asymmetric or swirling velocity profiles, extending the meter’s usable range and accuracy beyond what a single-path design can achieve.

Because the OPTISONIC 3400 relies purely on acoustic signal timing, it has no obstruction in the flow path, no components subject to erosion or wear, and no pressure drop across the measuring section. The direct-path configuration is also unaffected by internal pipe scaling, a common failure mode for clamp-on and reflective ultrasonic designs, preserving measurement accuracy over the meter’s operating life.

Engineering Design of the KROHNE OPTISONIC 3400

The KROHNE OPTISONIC 3400 is available in compact (integral electronics) and field-mount versions, with cable lengths to 30 m and optional IP68 sealing for submerged or flooded installations. The meter body is offered in flanged configurations up to ANSI Class 900/PN200 or with weld ends, and dedicated cryogenic (-200°C) and high-temperature (+250°C) versions extend the platform into LNG, chemical, and hot-process service. An optional heating jacket accommodates viscous or temperature-sensitive media that would otherwise crystallize or thicken in the measuring section.

Communication is provided via three independent 4-20 mA outputs with HART, alongside Modbus, FOUNDATION Fieldbus, and PROFIBUS PA/DP options, giving specifiers flexibility to integrate the OPTISONIC 3400 into existing plant control architecture. Extensive sensor and process diagnostics, including NE 107-compliant status reporting, continuously monitor signal quality, gain, and signal-to-noise ratio, and the platform is certified for use in Safety Instrumented Systems up to SIL2.

Key Features

The KROHNE OPTISONIC 3400 combines three-path ultrasonic accuracy with a maintenance-free, full-bore design suited to demanding process duty:

• Three-path ultrasonic measurement delivers ±0.5% accuracy with bi-directional flow capability over a wide dynamic range.
• Full-bore, completely welded construction has no moving parts, no wear, and zero pressure loss.
• Broad diameter range from DN25 (1 in) to DN3000 (120 in) covers dosing through large-diameter transportation pipelines.
• Cryogenic (-200°C) and extended temperature (+250°C) versions support LNG and hot-process applications.
• Pressure ratings up to ANSI Class 1500/PN200 handle demanding high-pressure process duty.
• Direct-path configuration eliminates measurement drift from internal pipe scaling.
• Extensive sensor and process diagnostics, including NE 107 status reporting, support predictive maintenance.
• SIL2 certification qualifies the OPTISONIC 3400 for use in safety instrumented systems.

Industrial Applications

The KROHNE OPTISONIC 3400 is widely deployed across chemical processing, oil and gas, marine, and water and wastewater applications wherever accurate, low-maintenance flow measurement is required across a broad range of viscosities and process temperatures. In Oman’s LNG and petrochemical sector, the cryogenic version of the OPTISONIC 3400 is specified for custody-transfer and process metering on liquefied gas and refrigerant lines where standard flowmeter technologies cannot operate.

As the officially authorized partner for KROHNE, Seven Star LLC distributes the OPTISONIC 3400 to water transportation authorities, desalination plants, and marine terminals across Muscat and the Sohar and Salalah economic zones. Its large-diameter capability up to DN3000 makes it a natural fit for regional bulk water transportation infrastructure, while its SIL2 safety rating supports critical process and custody-transfer duty across the GCC’s oil, gas, and chemical processing sector.

Technical Specifications

The table below summarizes the core specifications of the KROHNE OPTISONIC 3400 ultrasonic flowmeter.

Call To Action

Seven Star LLC invites process engineers, water authorities, and procurement teams to submit a formal RFQ for the KROHNE OPTISONIC 3400 ultrasonic flowmeter. Regional warehouse stock in Oman enables fast delivery across the GCC, and our instrumentation division can provide the full technical datasheet and sizing support needed to specify the correct diameter, pressure class, and temperature range for your application. As the authorized partner for KROHNE in Oman and the GCC, Seven Star LLC backs every OPTISONIC 3400 shipment with genuine manufacturer warranty and local technical support.