Explore Different Types of Mechanical Flow Indicator Equipment
Flow calibrating equipment can be mainly classified depending on the sort of flow calibration – either volumetric flow calibration or mass flow calibration. The flow indicator devices can also be classified depending on their principle of use. Let us have a brief discussion on different types of mechanical flow indicator equipment:
Classification of mechanical flow indicator equipment
- Oval gear flow indicator – It’s a positive displacement type flow indicator. It utilizes 2 or more oblong gears designed for rotating at right angles to each other, creating a T shape. The whole arrangement enables the creation of 2 sections in the chamber of flow indicator which are totally sealed from one another. The gear’s every rotation to a fixed liquid volume passing through the calibrator.
- Piston flow indicator – It performs on the rule of a piston oscillating inside a casing of known volume. A fixed quantity of liquid passes through the piston casing for every oscillation. Through the equipment associated with this piston, the dial of the indicator is utilized for counting the number of piston oscillations. So, total liquid which has passed through in a fixed time span is known. This flow indicator is basically used for residential water utilization calibration.
- Turbine flow indicator – It uses a turbine wheel for flow calibration. The turbine wheel sent in the liquid flow rotation path, supported by the liquid hitting the turbine blades. The rotation speed is proportional to liquid velocity hitting the blades and the indicator is measured accordingly for evaluating the flow perfectly. These are basically used in water distribution or fire water systems.
- Paddlewheel flow indicator and single jet flow indicator – These utilize a mechanism same as the turbine ones and contains an easy impeller wheel with the radical vanes, followed by a single jet. The wheel blades are smaller in width for paddle wheel flow indicator in comparison with the single jet flow indicator and are projected to a limited extent in the flow path.
- Variable area flow indicator/Rotameter – It contains a float and a vertical tapered glass tube within the tube. This arrangement is like the float is pushed up by the rise in flow because of viscous forces and higher pressure and again gravity pulls down the float if the rate of flow decreases. This indicator is measured for being used for a particular service, usually air or water.
- Multiple jet flow indicator – It is same as single jet flow indicator except that the steam is thrown on the rotating blades from many points thereby hitting different points on the turbine blades’ circumference. It reduces the wear on rotating blades.
- Nutating disc flow indicator – It utilizes an irregularly mounted disc that wobbles or nutates when the disc is hit by the liquid flow. The tilted disc creates a chamber for enabling the flow that remains on the disc’s one side. It is basically used for calibrating flow rates.
- Pelton wheel meter/Radial turbine flow indicator – It utilizes a radial turbine for converting the liquid flow into rotational speed for the turbine wheel that is measured for calibrating liquid flow and velocity.