KSV - Economical Micro Flow Meter

Economical Micro Flow Meter for Water & Air

The KOBOLD KSV, a compact variable area micro-flowmeter, is purpose-built for measurement of low flow rates of water and air, offering a dependable and cost-effective solution for applications where space is tight and accuracy is essential. With its economical price and fast delivery, the KSV is the go-to instrument for engineers who need a reliable flow measurement tool without the premium of a flow meter with complex electronics.

The KSV is designed specifically for panel installation, with a compact body and 1/8” NPT fittings that drop neatly into instrument panels, control cabinets, and OEM equipment enclosures. Offering a clear, direct reading at a glance, this meter requires no electronics for operation.

An optional integrated needle valve is available for simple for control and is generally recommended, particularly for gas applications, to help stabilize the float during media introduction.

How the KSV Works: Variable-Area Measurement Principle

Flow enters from the bottom of a vertically oriented tapered tube. The float inside rises until the upward drag force from the flowing fluid exactly balances the downward gravitational force on the float. At that equilibrium point, the float ‘s position indicates the flow rate read from the graduated scale on the tube.

This mechanical principle requires no external power and produces an instantaneous, direct-reading measurement. Because the KSV is calibrated specifically for water or air, readings are accurate and repeatable without the need for density corrections or additional signal processing, making commissioning and field verification straightforward.

Learn more about variable area and rotameter flow technology by visiting our in-depth Article on Variable Area and Rotameter Flow Technology.

Suited for Low Flow Rates and Harsh Media

The KSV is suited for very low flow rates of liquids and gases measuring flows as low as 0.04…04 GPH up to 2…20 GPH for water-based liquid and from 0.3…3 SCFH up to 10…100 SCFH for air. The flowmeters are rated to pressure up to 87 PSIG and for temperatures between -4 and 248°F.

The polysulfone body combined with either stainless steel fittings and FKM seals or brass fittings and NBR seals provides excellent chemical resistance for a variety of media including acids and alkaline solutions, making the KSV suitable for a wide range of process fluids beyond pure water. The float material varies by the chosen flow range with glass, stainless steel, and titanium float options available.

Key Features & Performance Highlights

• ±6% Full Scale Accuracy — reliable measurement across the entire operating range
• ±1% Full Scale Repeatability — consistent readings run after run, critical for process control
• Polysulfone body with excellent resistance to acids and alkaline solutions
• Float options: stainless steel, glass, or titanium dependent on the measuring range
• 1/8" NPT thread fittings for straightforward installation in standard instrument panels
• Optional integrated needle valve for flow regulation and float stabilization
• Compact form factor with convenient panel-mounting design
• No power required — fully mechanical, direct-reading operation
• Made in the USA — fast delivery from KOBOLD's Pittsburgh facility

Typical Applications of the KSV

The KSV's compact footprint, direct-read simplicity, and low cost make it a versatile fit across a wide range of industries and use cases:

• Laboratory and analytical instrumentation requiring precise micro-volume liquid flow control
• Chemical processing — monitoring reagent or additive dosing lines with aggressive media
• OEM equipment integration where panel-mount design and low flow ranges are required
• Electronics manufacturing — precise micro-flow control of process gases and cooling liquids
• Water treatment and filtration systems monitoring small-bore dosing or sampling streams
• Pilot plant and test rigs requiring low-cost, easy-to-read flow indication on water or air lines

Why Choose the KOBOLD KSV

Not every application needs a transmitter, a display, or a signal loop. Sometimes you just need to know the flow — accurately, reliably, and at a glance. The KSV is engineered for exactly that. Where other instruments add cost and complexity, the KSV strips measurement back to what matters: a rugged, proven mechanical design that is easy to install and easy to read.

Backed by KOBOLD’s decades of instrumentation expertise and manufactured domestically the KSV ships quickly and arrives ready to install. For applications where budget, simplicity, and performance all need to align, it is hard to beat.

BABA Compliant American Manufacturing

As a Build America, Buy America (BABA) compliant instrument manufactured in the United States, the KSV meets federal procurement requirements for infrastructure projects. This compliance ensures eligibility for federally funded programs — including water treatment facilities, municipal systems, and government industrial operations — while supporting domestic manufacturing capabilities. Government facilities and public utilities specify the KSV knowing it satisfies both performance requirements and procurement mandates.

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.