Visual Rotameter with Viscosity Compensation
The VKG, viscosity-compensated rotameter, delivers immediate visual flow readings through its borosilicate glass viewing window, eliminating dependency on electronic displays or external power sources. Engineered specifically for oil and viscous liquid applications, this instrument maintains accuracy across viscosity ranges from 1 to 540 cSt and density variations from 1 to 30 lbs/ft³—without requiring scale changes or recalibration.
Flow rates display directly in gallons per minute through the visual scale, eliminating conversion calculations. This direct-reading capability proves essential in critical applications where operators need immediate flow verification.
Engineered for Reliable Oil Flow Verification
The VKG's borosilicate glass construction withstands thermal shock while maintaining clear visibility. Operating pressures up to 175 PSI accommodate most industrial systems. Universal mounting capability allows installation in any orientation without recalibration.
Available with either nickel-plated brass or 304 stainless steel floats and fittings, 301 stainless steel springs and orifices, and NBR (brass models) or FKM (stainless steel models) O-rings the VKG addresses diverse chemical compatibility requirements.
Temperature ratings to 212°F (100°C) support heated applications, while the spring-loaded float design maintains consistent accuracy despite viscosity fluctuations from 1 to 540 cSt. Optional dual reed switch relay outputs enable automated control integration while preserving the primary visual monitoring capability.
Learn more about variable area and rotameter flow technology by visiting our in-depth Article on Variable Area and Rotameter Flow Technology.
BABA Compliant American Manufacturing
As a Build America, Buy America (BABA) compliant flow meter manufactured in the United States, the VKG meets federal requirements for public infrastructure projects. This compliance ensures eligibility for federally funded programs while supporting domestic manufacturing capabilities. Government facilities and public utilities specify the VKG knowing it satisfies both performance requirements and procurement mandates.
The visual nature of this instrument proves particularly valuable in infrastructure applications where operators need immediate flow confirmation without electronic vulnerability. Emergency generators and critical lubrication circuits benefit from the failsafe visual indication that continues functioning regardless of power availability.
Direct-Reading Scales Eliminate Conversion Errors
Factory calibrated scales provide direct flow readings without requiring corrections for viscosity common with water-calibrated meters. This eliminates calculation errors when monitoring oil service applications. Operators read actual oil flow rates instantly from the scale, improving response times and reducing training requirements.
Two different scale options are available, one directly on the glass viewing tube for light colored media or a magnetically coupled side mounted scale for dark media that would obscure an integrated scale.
Eleven flow ranges from 0.03 to 21 GPM accommodate diverse application requirements from precision lubrication to high-volume circulation. Each range optimizes float travel for maximum resolution while maintaining the wide viscosity compensation range without scale changes. The mechanical simplicity ensures decades of reliable service with minimal maintenance.
Proven Reliability in Critical Visual Monitoring
Industrial facilities worldwide rely on the VKG for applications where visual flow confirmation prevents costly equipment damage. Paper mills monitor oil flow to critical bearings, printing operations verify ink circulation, and hydraulic test facilities confirm flow during commissioning with direct observation.
The combination of visual accessibility, viscosity compensation without scale changes, optional relay output for automation, and American manufacturing creates a monitoring solution satisfying both operational requirements and procurement specifications. With quick availability from U.S. inventory and comprehensive technical support, the VKG provides dependable visual flow monitoring for industrial oil systems requiring transparent operational verification.
Flow Direction Specification May Be Required
**Important: This flow meter (model dependent) may require flow direction specification to complete your order.
While our product number identifies the meter's core specifications, flow direction is a critical parameter for certain models that must be specified separately to ensure proper performance and installation.
Why Flow Direction Matters
Flow meters are precision instruments engineered with internal components optimized for fluid movement in a specific direction, for certain models. Installing a meter that requires flow direction with an incorrect flow direction will not allow it to function properly.
What We Need From You
Please read the datasheet order table carefully (including any asterisks) and if your model requires a flow direction please specify your desired flow direction, in addition to your part number, when placing your order.
Flow directions are option/model-dependent but may include the following choices:
- Top to Bottom
- Bottom to Top
- Left to Right
- Right to Left
We cannot process orders without the required flow direction specification, if it is needed. Orders submitted that are missing this information are likely to experience delays in processing.
If you're unsure of your flow direction, our technical team is ready to assist you in determining the correct specification based on your system requirements at 412-788-2830 or customerservice@koboldusa.com.
Important Notice: Transitioning to U.S. Manufacturing
Due to the ongoing implementation of EU Directive 2020/2184 that restricts brass materials, product availability is subject to change at any time. We are actively reshoring production of our brass flowmeter models to U.S. facilities to ensure continued supply. Not all products can/will be reshored. During this transition, stock availability may fluctuate between the time of quotation and purchase order placement. We appreciate your patience as we work to establish our domestic supply chain and remain committed to providing you with the same high-quality products made closer to home.