FLOW ELEMENTS is a common term for differential pressure based flow meters. This is by far the most widely used method for measuring gas and liquid flow in the industry. A complete flow meter will, in addition to the flow element, consist of differential pressure transmitters and gauge fittings or complete measuring measures. This can be expanded with flow computer, temperature and pressure transmitter for compensation so that the measurement result can be calculated with accuracy that satisfies the requirements for purchase / sale installations.
Flow elements are used where repeatability is valued more than the measurement range normally limited to 1: 4. With today’s “smart” differential pressure transmitters that can easily change the measuring range, the practical measuring range can be increased to 1:10.
Flow measurement according to the differential pressure method is based on Bernoulli’s equation for energy balance. The sum of dynamic and static energy is constant in a circular tube, where the medium fills the entire pipe section. The flowing medium should be in a clean state and flow changes should take place slowly, ie without pulsations. A restriction (glare, venturi) in a pipeline will change the energy composition. The speed of the constriction is increased and the pressure changes. The pressure is measured before and after the restriction and the resulting differential pressure is the expression of the flow.
Between the differential pressure DP and flow Q, there is a square relationship that is expressed in the formula:
Can be supplied for flanges, in effect. ANSI, DIN, API, Gray type hubs etc. Pressure tap for measuring differential pressure can be supplied in the corner tapping, as a ring chamber in the flanges.
Measuring blenders are mainly manufactured according to the ISO 5167 standard. AUTEK itself carries out all the dimensioning and calculation of the equipment. The production is carried out by approved subcontractors.
Measuring nozzles can advantageously replace all measuring diaphragm installations. The permanent pressure drop will be lower than that of a measuring diaphragm, so that with the same diameter it will have approx. 50% higher capacity. The nozzle is also suitable when the medium contains solid particles or impurities or when the measuring element may be subject to measurement of steam flows or other high speed streams. Connection and pressure outlet directly or with ring chamber can be adapted to all standards.