Positive Displacement Flow Meters

The revolutionary KOBOLD VKM Viscosity-Compensated Flow Meter employs patented technology that delivers consistent ±4% full scale accuracy across dramatic viscosity variations up to 540 cSt and density fluctuations up to 30 lb/ft³, eliminating the measurement errors typically associated with changing fluid properties. Available in durable brass or stainless steel construction with pressure ratings up to 3600 PSIG and 5000 PSIG respectively, this versatile instrument features a spring-loaded float with precision orifice design that enables universal mounting in any orientation without requiring recalibration. The comprehensive VKM series offers flow ranges from 0.03 to 20 GPM with direct-reading scales optimized for oil applications, multiple connection sizes from ¼" to 1" NPT, and flexibility to incorporate 4-20mA output transmitters or digital displays with programmable switching capabilities. With operating temperatures up to 212°F, CSA-approved reed contacts, and the option for PNP 300mA switched outputs, this robust flow solution delivers exceptional reliability for hydraulic systems, lubrication circuits, cooling applications, and other demanding industrial processes where viscosity variations would typically compromise measurement accuracy. The VKM's innovative combination of metal construction, high-pressure capability, and patented compensation technology makes it an indispensable instrument for monitoring critical fluid systems where precise flow measurement is essential regardless of changing operating conditions.

The economical KOBOLD VKP Viscosity Compensated Plastic Flowmeter delivers reliable liquid flow measurement for applications where cost-effectiveness and chemical compatibility are paramount, featuring a rugged polysulfone construction with stainless steel internals that withstand temperatures up to 250°F and pressures to 230 PSI. Designed with KOBOLD's innovative spring-loaded float technology, this universal-mount flowmeter maintains ±5-7% full scale accuracy regardless of orientation, making it ideal for domestic services, cooling water circuits, lubrication systems, and solar heating applications. Available in multiple configurations with flow ranges from 0.5 to 26 GPM for water or 0.5 to 20 GPM for oil, the VKP includes direct-reading scales specifically calibrated for the intended media, providing instant visual indication at the upper edge of the float. The compact design incorporates standard 1" MNPT connections with options for brass or stainless steel union fittings in various sizes (½" to ¾" NPT), while specialized models for contaminated liquids handle particle sizes up to 400 μm without compromising performance. For automated monitoring and control applications, the VKP can be equipped with an adjustable bistable reed contact switch rated for up to 40W/40VA with convenient DIN 43650 C electrical connections, making this versatile instrument an exceptional value for both end-users and OEM implementations.