Factors Affecting Operational Accuracy of Orifice Metering for Incompress- ible Fluids

Flow measurement is the determination of the quantity of a fluid, either a liquid, or gas that passes through a pipe, duct, or open channel. In the physical world, engineers are frequently required to monitor or control the flow of various fluids. Orifice metering is one of the prime and easy ways of measuring the flowrates. It has the versatile application of fluid measurement in various industries such as oil and gas sector, polymer, and beverages, etc. The study presented in this paper is conducted to investigate mainly the variation in the measurement of flow discharge by altering the geometrical specifications of the orifice plate. With this purpose, the fabrication of required orifice plates is accomplished in the mechanical workshop. Experimental work is done on Armfield Flow Meter Demonstration Unit. Using the application of Bernoulli’s equation, the calculations of the theoretical volumetric flowrate and coefficient of discharge are carried out. This attempt suggests that the proper design of the orifice plate is very important to achieve the highest possible level of flow metering accuracy. The findings also suggest its periodic maintenance to prevent abnormalities such as contamination, corrosion, etc. as these can cause a huge error in the measurement of volumetric discharge. The highest discharge coefficient (0.88) was of a plate having orifice diameter 2.3 cm and angle 450◦. Based on all the experimental findings, the uncontaminated orifice plate with beta ratio (0.54) and bevel angle of 45◦was recommended which resulted in the highest discharge coefficient leading to the maximum accuracy. The proposed configuration can help industries at achieving the accurate flow metering which in turn can overcome the economic losses associated with flows. Keywords—Orifice plate, flow metering, discharge coefficient, beta ratio, bevel angle