PENAMBAHAN GAYA ANTI-BUOYANCY PADA JALUR PERPIPAAN YANG MELEWATI AREA RAWA

Abstract

Abstract – Swampy or rivers area have a buoyancy value that may lead to leakage or broken pipeline because it emerges to the land surface. Based on these issues, the pipeline in the area must be well designed and analyzed. A screw anchor addition as a buoyancy control is necessary so its system and design failure will not existed and it meets ASME B 31.8. The first step to carry out is to calculate the value of buoyancy ratio. Then its stress calculation was manually analyzed and by using CAESAR II software. Its result would be compared with stress criteria in ASME B31.8.The next step was to analyze its safety design so that the stress will not exceed the allowable stress of material by Ansys and  ASME B 31.8. The value of the ratio obtained on the manual calculation of buoyancy is ≤ 1.2 so buoyancy control is required. The screw anchor needed is as much as 18 pcs along 574,147 feet. The comparison results of manual stress is 62093.0444 psi and software is 62669.5693 psi. It has no more than 10% difference. Those results are still under allowable stress material of 65000 psi. The safety design of the screw anchor of 295 Mpa is still under allowable stress material of 448 Mpa. So based on the results, the addition of a screw anchor can be applied and acceptable on the pipeline.