The KOBOLD BVO is a variable area flow meter with an integrated adjustable switch, designed for OEM manufacturers that need rugged, reliable flow monitoring of water-like liquids without premium pricing. Made in the USA, the BVO covers six flow ranges from 0.1–1.0 GPM to 1.0–13 GPM with ±2% full-scale repeatability, brass or stainless steel wetted parts, and ¼" to 1" NPT connections.
Cost-Effective Flow Monitoring for OEM Applications
The BVO is designed for cost-conscious, large-volume OEM applications where ruggedness and reliability cannot be compromised. Through a streamlined production process, it offers the design quality and durability associated with KOBOLD's premium SV flow meter line at a price point that supports OEM profitability.
Each unit includes a factory-installed adjustable flow switch as standard equipment, eliminating the need for separate flow monitoring components and simplifying system integration for equipment manufacturers.
How the BVO Variable Area Flow Meter Works
The BVO operates on the proven variable area principle: a float rises in a cylindrical guide tube with conical slots along its periphery as fluid flows upward, and each float position corresponds to a specific flow rate. A graduated scale on the borosilicate glass measuring tube provides direct visual flow indication.
Permanent magnets embedded in the float activate an external reed switch through the tube wall, so the contact remains hermetically separated from the process media. This isolation contributes to system reliability and helps reduce maintenance requirements.
Construction Built for Industrial Environments
The BVO pairs a gold anodized aluminum housing with a borosilicate glass measuring tube and a choice of nickel-plated brass or 304 stainless steel wetted parts. According to specifications, it is rated for media temperatures from –10 °F to 212 °F (–23 °C to 100 °C) and pressures up to 145 PSIG (10 bar).
Brass models use nickel-plated brass fittings with NBR O-rings; stainless steel models use 304 stainless steel fittings with FKM O-rings, providing material compatibility options for diverse fluid applications. The borosilicate glass tube offers chemical resistance and thermal stability, and the switch housing carries IP65 electrical protection. This construction is designed for continuous flow monitoring in water treatment systems, industrial process equipment, and other OEM applications.
Integrated Adjustable Flow Switch
Every BVO includes a normally open (N/O), 2-pole reed contact switch that is adjustable over the meter's entire operating range. An optional SPDT changeover contact is available by adding the "U" suffix to the model number, for applications requiring both normally open and normally closed functionality.
According to specifications, the switch is rated for a maximum of 230 VDC / 0.26 A / 60 W or 240 VAC / 0.42 A / 100 W and is cCSAus approved. Magnetic activation keeps the reed contact isolated from the flowing medium, and the IP65-rated switch housing accepts standard electrical connections for integration into control systems.
Six Flow Ranges and Model Options
The BVO line offers six factory-calibrated flow ranges for water-like liquids: 0.1–1.0 GPM (¼" NPT), 0.2–2.0 GPM (¼" NPT), 0.53–2.6 GPM (½" NPT), 1.0–5.0 GPM (½" NPT), 0.79–9.2 GPM (¾" NPT), and 1.0–13 GPM (1" NPT).
Brass models carry BVO-61.. model numbers (BVO-6102 through BVO-6150) and stainless steel models carry BVO-62.. model numbers (BVO-6202 through BVO-6250). Pressure loss at maximum flow ranges from 0.9 to 2.1 PSIG depending on model. Total installed length ranges from 5.31" to 6.85" (135–174 mm), supporting integration in space-constrained equipment designs. The meter installs vertically with upward media flow using standard NPT threaded connections.
Made in USA and BABA Compliant for Government Projects
The KOBOLD BVO flow meter is manufactured in Pittsburgh, Pennsylvania, making it fully compliant with Build America, Buy America (BABA) requirements. This domestic manufacturing designation qualifies the BVO for federal infrastructure projects, government facility installations, and other applications requiring American-made instrumentation.
BABA compliance provides significant advantages for OEM manufacturers serving government, municipal, and public sector markets: equipment incorporating BABA-compliant components meets federal procurement requirements for infrastructure projects, including water treatment systems, municipal facilities, and transportation infrastructure. American manufacturing also supports shorter lead times, reduced supply chain complexity, and direct access to Pittsburgh-based engineering and technical support.
Variable Area Flow Technology
Learn more about variable area and rotameter flow technology by visiting our in-depth Article on Variable Area and Rotameter Flow Technology.
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.
Common Questions about BVO - Flow Meter with Switch
Six factory-calibrated ranges for water-like liquids span 0.1–1.0 GPM up to 1.0–13 GPM: 0.1–1.0 GPM and 0.2–2.0 GPM with ¼" NPT, 0.53–2.6 GPM and 1.0–5.0 GPM with ½" NPT, 0.79–9.2 GPM with ¾" NPT, and 1.0–13 GPM with 1" NPT fittings.
According to specifications, the BVO provides ±10% of full scale accuracy and ±2% of full scale repeatability. The included reed switch is adjustable over the meter's entire operating range, so the switching point can be set anywhere within the selected flow range.
The BVO is designed for clean, low-viscosity, homogeneous, water-like liquids that do not attack the wetted materials. High-viscosity media cause large measuring errors, and large dirt particles can block the float. For media carrying ferritic particles, a magnetic filter is recommended.
According to specifications, the BVO is rated for media temperatures from –10 °F to 212 °F (–23 °C to 100 °C) and a maximum operating pressure of 145 PSIG (10 bar). For outdoor installations, the glass measuring tube must be protected from freezing of the medium.
A normally open (N/O), 2-pole reed contact comes standard. An SPDT changeover contact is optional — add the "U" suffix to the model number (for example, BVO-6216U). Maximum switch ratings are 230 VDC / 0.26 A / 60 W and 240 VAC / 0.42 A / 100 W, and the switch is cCSAus approved.
The meter installs vertically in the pipework with media flowing from bottom to top. Seal the NPT connection threads with Teflon tape or similar, support the inlet and outlet pipes approximately 2" (50 mm) from the connectors, and hold the process connectors with a suitable wrench during mounting to protect the measuring glass.
Yes. The BVO is manufactured in Pittsburgh, Pennsylvania, and BABA (Build America, Buy America) compliant models are available. This qualifies the BVO for federal infrastructure projects, government facility installations, and other applications that require American-made instrumentation and federal procurement compliance.
Brass models (BVO-61..) use nickel-plated brass wetted parts with NBR O-rings; stainless steel models (BVO-62..) use 304 stainless steel with FKM O-rings. Both use a borosilicate glass measuring tube. The two constructions provide material compatibility options for diverse fluid applications.
With uncontaminated media, the BVO is almost maintenance-free. If contamination, calcium, or algae deposits appear, the internal parts should be cleaned regularly; they are accessible after removing the top connection. Replacing the O-rings of the screwed connections after cleaning is recommended, and spare parts are available.