PERANCANGAN ALAT UKUR HEAD LOSS MAYOR MENGGUNAKAN PIPA PVC ½”
Abstract
The measurement practice tool of head loss mayor was designed and used as learning media to support the subject of fluid mechanics. The importance of the knowledge about head loss mayor as learning media made this tool have to be created. In Mechanical Engineering Study Program of Universitas Muhammadiyah Yogyakarta, there has already been head loss mayor measurement tool with iron pipe, but usually in plumbing system it should use PVC pipe. Thus, it was better if the modelling of the head loss mayor measurement tool used PVC pipe.
The designing method of the head loss mayor measurement tool was through determination stages of the need of the design by measuring the pipe diameter, pump capacity, rotameter, and manometer. By adjusting the measure of the pipe diameter and maximum Reynolds number, the maximum flow debit would be obtained. Then, the data of the maximum flow debit were used to count the maximum flow speed. The pump determination was started from the calculation of head static, head pressure, and head loss. After all the heads were calculated, then the total head would be obtained. The value of the maximum flow debit and the total head, the pump could be used as a parameter of pump determination, and by the data of the maximum flow debit, rotameter could be determined. The manometer determination could be obtained from the data of the pipe roughness number, the pipe diameter, and maximum Reynolds number. Thus, the value of friction coefficient could be obtained from Moody diagram as a starting data to calculate the head loss mayor needed to find the difference of height, and the manometer used could be determined. After all the designing components were calculated, the next step was the design and making of the tool.
The result of the designing showed that the pump needed was a pump with capacity of more than 25 LPM and the Reynolds number of 1174 < Re < 293556. Then, the result of the test obtained the average value of the friction coefficient for laminar flow of 0.054, the transition flow of 0.054, and the turbulence flow of 0.0345. The deviation of the measurement tool of head loss for the friction coefficient value in the laminar flow was 27.48%, the transition was 22.04%, and turbulence was 22.39%. The test proved that the highest accuracy level was in the transition flow, while the lowest accuracy was in the laminar flow.