Original Japan Yokogawas RAMC05 Variable Area Flow Meter

Yokogawa RAMC05 Metal Tube Rotameter – Detailed Introduction

Model Overview:

The RAMC05 is part of Yokogawa’s RAMC series of metal tube variable area flowmeters designed for measuring flow rates of liquids, gases, and steam in a wide range of industrial applications. Unlike glass rotameters, RAMC05 uses a stainless steel measuring tube and an internal float, making it ideal for high pressure, high temperature, and corrosive applications.

Working Principle:

The RAMC05 operates on the variable area principle:

• As the fluid enters from the bottom and flows upward through the tapered metal tube, it lifts the float.
• The float rises until the upward force from the fluid equals the downward gravitational force.
• The position of the float is proportional to the flow rate.
• A magnetic coupling transmits the float position to an external indicator (mechanical or electronic).

Technical Specifications:

Available Variants / Codes:

The RAMC05 is modular and can be configured as:

• RAMC05-A: Local indicator only (no external power needed)
• RAMC05-E: With electronic transmitter (4–20 mA / HART)
• RAMC05-EX: Explosion-proof with ATEX/IECEx certified electronics
• RAMC05-S: Sanitary version (available upon request)

Typical Media Compatibility:

• Clean or slightly contaminated gases (air, nitrogen, hydrogen, etc.)
• Liquids including water, oils, acids, alkalis
• Steam (saturated or superheated, with pressure compensation)

Options & Accessories:

• Flow restrictors or damping devices for pulsing flow
• Stainless steel or coated housing for harsh environments
• Heated enclosures for low ambient temperatures
• Remote indicators for control rooms

Typical Applications:

• Chemical dosing and blending
• Air / gas monitoring in utilities
• Cooling water control in power plants
• Boiler feed monitoring
• Process gas flow in refinery or pharma lines

Compliance & Certifications:

• CE, SIL2 (with proper configuration)
• ATEX / IECEx Zone 1 and Zone 2
• NACE MR0175 compliance (for sour gas)
• PED, RoHS