Variable-area flow meter VKM

volumefor high-viscosity liquidsfor liquids

Overview
The KOBOLD VKM flowmeters and switches use a spring-loaded float in a cylindrical measuring tube with an integrated orifice, enabling viscosity compensation and substantial density compensation even at low flow rates.

Key features

• Designed for viscous liquids
• Measuring / switching range: 0.2 - 0.5 ... 8 - 80 l/min (liquid)
• Viscosity range: 1 - 540 mm²/s
• Connection options: G ¼ ... 1; ¼ ... 1" NPT female thread
• Materials: brass or stainless steel
• Maximum pressure (p_max): 250 bar (brass), 350 bar (stainless steel)
• Maximum temperature (t_max): 100°C
• Output: up to 2 switching contacts (potential-free), 1 analogue output
• Power supply: 24 V AC/DC; 24 V DC ±20 %; max. 250 V AC
• Electrical connection: plug DIN EN 175301-803 or cable
• Accuracy: ±4 % of full scale
• Options: block valve BVB; with ADI: analogue output, counter, digital display, relays, panel mounting
• Approvals: cCSAus, ATEX, IECEx

Operation
The patented float contains a permanent magnet that actuates a potential-free bistable reed contact mounted outside the flow path, ensuring hermetic separation between the medium and the electrical switching system. The contact is housed in a height-adjustable plastic enclosure to protect it from mechanical stress or aggressive atmospheres. As flow increases the float rises; when its magnetic field reaches the reed switch tips the contact closes. The float stops at a mechanical end position preventing it from leaving the magnetic operating range so the contact remains closed for reliable bistable switching.

Specifications

• Model: VKM
• Intended medium: viscous liquids
• Measuring / switching range: 0.2 - 0.5 ... 8 - 80 l/min
• Viscosity: 1 - 540 mm²/s
• Thread connections: G ¼ ... 1; ¼ ... 1" NPT female
• Materials: brass or stainless steel
• Max. pressure: 250 bar (brass), 350 bar (stainless steel)
• Max. temperature: 100°C
• Outputs: up to 2 potential-free switching contacts, 1 analogue output
• Power supply: 24 V AC/DC; 24 V DC ±20 %; max. 250 V AC
• Electrical connection: DIN EN 175301-803 plug or cable
• Accuracy: ±4 % of full scale
• Options: ADI module (analogue output, counter, digital display, relays), panel mounting, block valve BVB
• Approvals: cCSAus, ATEX, IECEx