Control instrumentation distributor and manufacturer Instrotech is offering the latest Kobold Model VKP flowmeter that works on the Variable Area principle, still one of the most-used measurement principles in flow engineering.

Instead of the conical measuring pipe generally used, a conical mandril is placed inside a housing made out of robust, impact resistant polysulfone, on which there is a float with a sharp-edged orifice.

The incoming medium flows through the float’s orifice and lifts it up against the power of a stainless steel spring onto the flow depending height. The actual flow rate can directly be read off a scale affixed to the outside of the housing.

Further, with the combination of spring and conical mandril, this series of meters is far more compact than other commonly used devices with a conical measuring pipe. They are therefore ideal for measuring flow rates in machines and aggregates.

These devices can be installed in any position without additional calibration, making them ideal as a transportable measuring device or for installation in flexible pipes, such as hoses.

The use of a sharp-edged orifice float makes the devices relatively insensitive to viscosity and, consequently, are highly suitable for flow measurement of oil, since its viscosity alters with changes in temperature.

A specially designed float, fitted with grooves around the outer periphery, also permits the measurement of impure fluids containing particles of up to 400 µm. Measuring ranges between 2 ℓ/min and 100 ℓ/min of water or oil are available.

The standard connections are G1 and 1" NPT. Other available connections are brass solder pipe connections, polyvinylchloride glue-in connections or G ½ or G ¾ threaded connections. The simple construction of the device and the use of just a few parts keeps the price of the instrument low and makes it eminently suitable for large-scale use. The devices can be equipped with an adjustable, bistable reed-switch for monitoring flow rates.