RCM Flo-Gage Series 7000 and 8000 Direct-Reading Flow Meter

RCM Flo-Gage Series 7000 and 8000 Flow Meters

The RCM Flo-Gage is a direct-reading differential-pressure flow meter for industrial liquid and gas applications. A built-in calibrated nozzle creates a pressure differential related to the flow rate, while the large analogue dial displays the measurement directly in engineering units such as GPM, L/min, SCFM or Nm³/h.

The Flo-Gage is self-contained and does not require separate orifice plates, impulse tubing, equalising valves or an external differential-pressure indicator. Its robust in-line metal construction is suitable for applications where durability, simple operation and clear local indication are important.

Key Features

• Direct-reading flow indication without external electrical power.
• Large 3.5-inch or 90 mm analogue dial.
• Expanded 270-degree scale for convenient reading.
• Factory-calibrated scale in the required engineering units.
• Suitable for both clear and opaque compatible fluids.
• Approximately 6:1 standard measuring range.
• Standard accuracy of ±3% of full scale.
• Repeatability of approximately ±1% of full scale.
• Rugged in-line metal body designed to withstand piping stresses.
• Threaded Series 7000 and wafer-style Series 8000 versions.
• Optional reed switches for high-flow or low-flow alarms.
• Optional transmitter outputs for remote indication, control or totalisation.

Flo-Gage Measurement Principle

The Flo-Gage operates using the differential-pressure principle. As fluid passes through the meter’s calibrated nozzle, it creates a pressure difference between the upstream and downstream sensing points. This differential pressure moves the internal bellows mechanism and positions the pointer on the calibrated flow scale.

The pressure difference is proportional to the square of the flow rate. The dial is factory calibrated so the operator reads flow directly without performing a differential-pressure calculation.

Series 7000 and Series 8000

General Specifications

Pressure and temperature limits depend on the body material, seals, process connection and selected options. Confirm the complete model specification for the intended application.

Compatible Liquids

The liquid Flo-Gage is suitable for water and many low- or medium-viscosity liquids that do not deposit solids inside the measuring passage and are compatible with the selected wetted materials.

• Potable and non-potable water
• Chilled and hot water
• Cooling water
• Glycol-water mixtures
• Fuel and lubricating oils
• Gasoline and compatible fuels
• Compatible solvents and chemicals
• Industrial and process liquids

Standard liquid configurations can accommodate viscosities up to approximately 500 cP, subject to application review and calibration. Provide the liquid name, specific gravity and viscosity when requesting a quotation.

Gas and Steam Measurement

Gas-calibrated Flo-Gage models are available for compressed air, nitrogen, oxygen, carbon dioxide and other compatible non-toxic industrial gases. Gas scales are normally specified in SCFM or Nm³/h for defined reference conditions.

Selected configurations are available for saturated or superheated steam. Steam service requires the appropriate high-temperature construction, seals, pressure rating, scale and installation arrangement.

Typical Flow Ranges

The complete catalogue contains the available full-scale ranges for each pipe size. Select a scale that places the normal operating flow within the upper half of the dial whenever possible.

Optional Reed-Switch Outputs

The Flo-Gage can be fitted with one or two independently adjustable SPDT reed switches. These switches can provide high-flow or low-flow signalling for alarms, pump protection, equipment interlocks and control circuits.

The example above shows a Flo-Gage with reed switches integrated into a chiller system to detect a low cooling-water flow condition.

Optional Transmitter Outputs

Electrical transmitter options allow the indicated flow to be sent to a PLC, DCS, recorder, remote display or building-management system. Available configurations depend on the model, application and required output.

Confirm the power supply, output type, electrical load, receiving-device input and hazardous-area requirements before ordering.

Typical Applications

• Chilled-water and hot-water systems
• Chillers and heat exchangers
• Cooling-water monitoring
• Pump and compressor protection
• Lubrication and hydraulic-oil systems
• Water-treatment equipment
• Compressed-air monitoring
• Industrial gas distribution
• Food and beverage processing
• Chemical and solvent flow measurement
• Pharmaceutical purified-water systems
• Industrial steam systems with the appropriate steam configuration

Selecting the Correct Flo-Gage

Select the Flo-Gage according to the actual process conditions, required flow range and output—not pipe size alone. A correctly selected scale improves readability and keeps normal operation within the preferred portion of the measuring range.

Provide the following information when requesting a quotation:

• Liquid or gas name and composition
• Minimum, normal and maximum flow rate
• Preferred engineering units
• Pipe size and connection type
• Operating and maximum pressure
• Operating and maximum temperature
• Liquid specific gravity and viscosity
• Gas reference pressure and temperature
• Preferred wetted materials and seals
• Local indication only or remote output
• High-flow or low-flow switching requirements
• General-purpose or hazardous-area installation

Reading the Analogue Scale

The minimum readable flow is normally approximately 15% of full scale. For clearer reading and improved practical performance, select a meter that places normal operation within the upper half of the scale.

Do not select an unnecessarily high full-scale range. An oversized range compresses the normal operating point into the lower part of the dial and makes small flow changes more difficult to observe.

RCM Flo-Gage Supplier and Technical Support

Seacom Process Instruments supplies and supports RCM Flo-Gage Series 7000 and 8000 flow meters for liquid, gas and selected steam applications. Our team can assist with flow-range selection, process connections, materials, calibration units, alarm switches and transmitter outputs.

Contact Seacom with the process medium, flow range, pressure, temperature, pipe size and output requirements so we can recommend the appropriate Flo-Gage configuration.