Tokyo Ryuki Kogyo ODM-300SST Differential Pressure Flow Meter

Tokyo Ryuki Kogyo ODM-300SST Differential Pressure Flow Meter

The Tokyo Ryuki Kogyo ODM-300SST is a differential pressure (DP) flow meter engineered for continuous volumetric and mass flow rate measurement in harsh engine room and process environments. Combining an integrated primary flow element (orifice/nozzle assembly) with a high-accuracy capacitive or piezoresistive differential pressure transmitter, the ODM-300SST converts the square-root relationship of fluid pressure drop across a restriction directly into a linear 4–20 mA DC analog output signal. Constructed with SUS316L stainless steel wetted parts and a die-cast aluminum explosion-proof housing, this unit withstands severe mechanical vibration, high ambient temperatures, and corrosive marine atmospheres.

Model Details

• Manufacturer: Tokyo Ryuki Kogyo Co., Ltd. (Japan)
• Base Model: ODM-300SST
• Manufacturer Part Number (MPN): ODM-300SST (Standard configuration; suffix codes denote flange rating, bore size, and calibration range, e.g., ODM-300SST-10K-25A)
• Sensing Principle: Differential Pressure with integrated Square-Root Extraction
• Condition Available: New Unused Surplus

Features

1. SUS316/SUS316L Wetted Construction: Measuring diaphragms, process flanges, and vent/drain plugs are machined from marine-grade stainless steel to resist pitting from heavy fuel oil (HFO), marine gas oil (MGO), and treated boiler water.
2. High Static Overpressure Protection: Dual-diaphragm overload protection mechanism prevents sensor zero-shift or rupture when subjected to sudden line surges or improper manifold valve sequencing up to 14 MPa.
3. Zero & Span Field Adjustability: Non-interacting external magnetic or potentiometer adjustments allow onboard Chief Engineers and ETOs to trim zero-point drift without breaking the weatherproof enclosure seal.
4. Vibration & Thermal Immunity: Silicon-oil-filled sensor capsule and potted SMD electronics maintain FS accuracy across engine room ambient temperatures up to 80°C and continuous 4G vibration loads.

Compatible Marine & Industrial Systems

• Main & Auxiliary Diesel Engines: MAN B&W (MC/ME series), Wärtsilä (RT-flex / W-series), Daihatsu, and Yanmar fuel oil supply/return monitoring skids.
• Marine Auxiliary Boilers: Osaka Boiler, Miura, and Kangrim feedwater and steam flow control loops.
• Automation & Alarm Monitoring Systems (AMS): Kongsberg AutoChief / K-Chief, Terasaki, JRCS, and Nabtesco engine control consoles accepting standard 4–20 mA passive/active inputs.

Part Number Cross-References

• Tokyo Ryuki Kogyo: ODM-300SST / ODM-300S / ODM-200SST (Legacy predecessor)
• Yokogawa Equivalent: EJA110E / EJA115E (Low-flow orifice DP transmitter)
• Fuji Electric Equivalent: FKC / FKD Series Differential Pressure Transmitter
• Yamatake (Azbil) Equivalent: GTX30D / GTX31D

Applications

• Heavy Fuel Oil (HFO) and Marine Diesel Oil (MDO) viscosity/consumption booster modules
• Auxiliary boiler feedwater flow regulation and drum level three-element control
• Main engine jacket cooling fresh water (JCFW) and central cooling loop monitoring
• Bilge water separator (OWS) discharge flow verification
• Inert Gas System (IGS) scrubber sea water supply monitoring
• Cargo pump discharge and ballast water treatment system (BWTS) flow metering

Frequently Asked Questions

What is the difference between the Tokyo Ryuki Kogyo ODM-300SST and standard DP transmitters?

The ODM-300SST is specifically engineered with marine-grade SUS316/SUS316L wetted parts, high vibration resistance, and integrated primary flow element compatibility for shipboard fuel, water, and steam systems, whereas general industrial DP transmitters often lack marine shock/vibration ratings and JIS marine flange interfaces.

How do I wire the 4–20 mA output of the ODM-300SST to a ship’s PLC or Alarm Monitoring System?

Connect the 24 V DC positive power supply wire to Terminal 1 (+) and the signal return wire (going to the PLC analog input card) to Terminal 2 (-). Ensure the total loop resistance, including cable resistance and PLC input impedance, does not exceed 600 Ohms at 24 V DC.

Can the ODM-300SST measure Heavy Fuel Oil (HFO) flow rates accurately?

Yes. Provided the HFO is maintained above its pour point via heat tracing to keep Reynolds numbers within the primary element’s calibrated range, the SUS316L diaphragm and linear 4–20 mA square-root output accurately measure HFO volumetric flow.

How do I bleed air from the ODM-300SST sensing chambers during commissioning?

With the equalizing valve open and low-pressure isolation valve closed, slowly crack open the high-pressure isolation valve. Loosen the upper vent plug on the high-pressure flange until bubble-free liquid emerges, tighten the plug, and repeat the procedure on the low-pressure chamber before closing the equalizing valve.