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Hot tapping process analysis on gas distribution pipes online service using Shielded Metal Arc Welding Budi Prasojo; Yunan Sadli Nasution; Endah Wismawati; Subagio So’im; M. Ari
Journal of Welding Technology Vol 4, No 1 (2022): June
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jowt.v4i1.2953

Abstract

In a piping system makes it possible to add branching into an existing piping system. In this research will discuss about installation 12 " branch pipe in to 16” existing pipe. The system should be installed without interrupting the operation of the pipeline to avoid huge losses. Hot-tapping is a technology that works to create branching on the online service pipe condition. Calculation and analysis of the results to ensure the process of hot-tapping absolutely safe to operate. parameters that must be considered include the heat input, the operating pressure during welding hot-tapping process with Shielded Metal Arc Welding, stress that occurs at the branching system. Analysis on split tees must be done because of stress that occurs due to the welding process and the reduction in thickness. Analysis on the plumbing system must be done because of a new branching thus causing new stress. The results of the analysis on split tees and the pipe system is used as a reference-making procedures for implementing hot-tapping. Maximum stress that occurs in the pipes during hot-tapping process is the welding area (22.828 psi). The welding process causes melting partial in the metal pipe so, during welding process (hot-tapping) working pressure should be reduced by 25.27%. The condition of the fluid in the existing pipeline still safe because liquefaction as a result of the welding process does not penetrate to the inner pipe. The new design results in branch pipe eligible to fabricated because stress that occurs is still below the allowable stress values
Analysis of Performance Losses Related to Shaft Angle on Fishing Boats Using the Free Running Model Test Method Aang Wahidin; Rachmad Tri Soelistijono; Fitri Hardiyanti; Lilik Subiyanto; Gaguk Suhardjito; Subagio So’im
International Journal of Marine Engineering Innovation and Research Vol 8, No 2 (2023)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25481479.v8i2.16417

Abstract

Several traditional fishing boats in Sendang Biru, Malang Regency are of the sekoci type using an inboard engine drive system with the position of the propeller shaft installed at an angle to the ship's base line. Based on the theory can reduce the performance of the ship propulsion system up to (2-3)%. In this research, we analyzed how much performance was lost/decreased on the lifeboat type fishing boats installed above. The method we use is the Free Running Model Test by making a model of a traditional fishing boat type of lifeboat with a model size of Loa = 100 cm, Lwl = 80.72 cm, B = 19.7 cm, H = 10.68 cm and T = 5, 08 cm made of aluminum sheet. The Free Running Model Test uses 1 motor and propeller which has a thrust of 60 watts, remote control equipment uses the main component of the NRF24L01 transceiver which works at a frequency of 2.4 Ghz with a range of 240 meters to 1 kilometer with conditions without obstacles and camera equipment drone to record the track. The results of this study show that there is a decrease/loss of performance at a 3-degree angle of 0.24%, at a 5-d. gree angle of 0.49%, at a 10-degree angle of 2.52%, at a 15-degree angle of 4.41% and at an angle of 20 degrees of 6.48%.