Custom flow meter manufacturer and distributor Litre Meter has cemented its continued relationship with Bosch Rexroth by supplying a further 20 KRAL Volumeter helical screw flow meters for R & D rigs at the drive and controls solutions firm.
Litre Meter has already supplied a number of meters for the current test rig at the company”s production facility at Glenrothes, Scotland. These additional meters are for a range of new test rigs. Litre Meter has been supplying Bosch Rexroth with KRAL meters for R & D rigs since 2003.
Commenting on the selection of KRAL meters from Litre Meter, Alasdair Johnstone, managing director of Bosch Rexroth Drive & Control Technology at Glenrothes, said: “We decided to use these particular meters in all our R & D and production test rigs based on the exceptional level of accuracy which they offered – something we felt was essential in order to have total and demonstrable confidence in the results that were being produced.”
OM positive displacement meters from KRAL can be used in a large number of applications covering liquids with a range of viscosities.
The basic meter, produced by KRAL of Austria, is derived from a range of screw pumps that has been widely used for over 50 years. These units were supplied to Bosch Rexroth with sensors designed for higher temperature applications. However, the units can be supplied with the Litre Meter standard or intrinsically safe pick-up and pulse output transmitter system.
A positive displacement meter works by dividing the flow into discrete “pockets”. This prevents the flow by-passing the meter”s rotor and producing errors. The helical screw flowmeter has rotor scrolls which accept and release continuous flow. While the flow is being transported through the centre portion of the meter it is trapped by the “flights” of the scrolls, which form positive displacement “pockets”. A sensor detects the motion of the rotor and produces a high resolution pulse output.
Litre Meter CEO Charles Wemyss said: “Litre Meter was able to select from a range of KRAL flowmeters. Aluminium OME units suitable for pressures up to 40 bar were used on some return lines. Cast iron OMG meters were used for most of the other applications apart from those over 250 bar where the OMH units were employed.
“Additionally the latter were fitted with two custom sensors enabling flow direction to be resolved.”