Pump shafts are generally exposed to the liquid being pumped either on a continual basis or at certain locations along the length of the shaft. The shaft material is austenitic stainless steel, description ASTM AU 79 TY 316. The purpose of this study is to determine the failure of the water pump shaft used in the power plant. Metallography is the study of structure metal shaft can used as a means for CWP metal pelleting (Circulating Water Pump), for the purpose of damaged or deeply degraded areas. SEM test is used to know the beginning of the crack (crack initiation). EDS test is used to chemical composition and Vikers hardness test is also used to know the hardness material. These three tests to support in analyzing the failure of the pump shaft. The conclusion of this failure analysis is the shaft material has porosity. Fatigue cracking comes from the outer surface area.
Fresh water generator (FWG) merupakan salah satu alat di kapal yang digunakan untuk merubah air laut menjadi air tawar. Ejektor adalah salah satu komponen penting pada FWG. Kinerja ejektor berpengaruh terhadap jumlah produksi air tawar yang dihasilkan. Ejektor berfungsi untuk memvakumkan ruangan pada evaporator serta menghilangkan brine/ air garam (air dengan salinitas tinggi) dari bagian bawah ruangan evaporator. Secara umum ejektor merupakan pompa statis yang bekerja berdasarkan dengan prinsip kevakuman. Kevakuman yang terjadi pada ejektor sangat mempengaruhi performa dan kemampuan hisap sisi secondary flow (suction area). Tujuan penelitian ini adalah mengetahui pengaruh variasi diameter exit nozzle pada ejektor terhadap tekanan dan kecepatan di secondary flow (suction area) yaitu pada sisi isapan udara (vakum). Penelitian ini dilakukan secara simulasi numerik menggunakan software komersial CFD untuk memprediksi fenomena aliran fluida yang melewati nozel pada ejektor dengan memvariasikan diameter exit nozzle meliputi 5, 6, dan 7 mm. Tekanan masuk (primary flow) pada nozel adalah 400 kPa (4 bar). Jarak antara ujung exit nozzle dengan pipa aliran keluar dibuat dengan posisi tetap. Ujung exit nozzle berada pada posisi 3 mm masuk ke dalam pipa saluran keluar yang diukur dari posisi ujung bagian dalam. Hasil simulasi menunjukkan ejektor dengan diameter exit nozzle 7 mm menghasilkan tekanan terbesar yaitu 2,92 bar dan memberikan performansi yang optimum dengan menghasilkan tekanan di secondary flow (suction area) sebesar 0,81 bar sehingga menyebabkan tingkat kevakuman pada ruang evaporator semakin cepat. Semakin cepat ruang evaporator vakum maka semakin cepat pula dimulainya proses pembuatan air laut menjadi air tawar pada alat FWG
In carrying out of duties as a teacher, in addition to teaching, a teacher also required to be able to make a good scientific work. Writing ability is one of main subject of the teacher when purpose a scientific work. But the reality, still faced some teachers that minus of ability on purpose a good scientific work. Using the latest version of application technology that improved purposes scientific work progress not fully handle as well by teachers on SMA N 1 Limbangan is one of issue for the present time. FGD (Focus Discussion Group) that doing by polimarin lectures and SMA N 1 Limbangan teachers expected can improve kowladge and ability of the teachers on literature skill and purposing scientific work (chapter book) as an obbilgation of the teachers on SMA N 1 Limbangan. The result of FGD is given knowledge and skill for the teachers for using Mendeley application as a tool for citation a reference. Aside from that given knowledge and skill for the teachers abaout paraphrase of the words, its have benefite for teacher for purposing scintifics work without doing plagiarism. And the last is given knowledge and skill about using application of electronic information system called SCI hub for downloading some journal as a reference for purposing scientific work for free.
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