ANALISIS PENURUNAN SISTEM KOMPRESOR PADA PEMBANGKIT PT. INDOCEMENT TUNGGAL PRAKARSA, TBK. KALIMANTAN SELATAN

Supply of compressed air has an important role in continuity of operation power plant, failures that occur in operation of engine in this unit can affect all plant operations that can result in decreased production levels. To determine the magnitude of loss of pressure or energy loss lost in pressurized air piping system at plant located in PT. Indocement Tunggal Prakarsa, Tbk. Tarjun Plant-12. Evaluation of pressure reduction losses in the air system is focused on losses caused by system leakage and pressure drops in the distribution lines caused by several factors including friction in straight pipes, bends, fittings, reducers and existing components, and knowing the loss of costs due to compressor pressure drop. The pressure drop in the pipe is very dependent on pipe diameter, besides distance and supporting components on piping system also affect the pressure drop. Based on calculation, there was a decrease in pressure of 1603660,895 Pa, from pressure drop caused by friction of straight pipe and connection and actual condition of pipe surface which was likely to have been corroded, making surface rough. system decline that occurred in the compressor resulted in a loss of operational costs of 5,760,451 rupiah / week.

Solutions to enhance technology in the fabrication process and installation of marine pipelines

The article describes possible solutions of the problem connected with shortening shipbuilding construction time as well as reducing production costs. To reduce the total amount of labour involved in the manufacture and installation of ship piping systems, which is 20% compared to the total labour volume of shipbuilding, authors provide the research on the possibility of manufacturing straight pipe sections with permissible deviations in combination with free flanges, analysis of deviation compensation for pipelines through the use of straight pipe sections manufactured with permissible tolerance and proposing new theoretical solutions to improve manufacturing and installing ship piping systems. Introduction of these technologies contributes to reduction of cycles of building and decrease in labour-intensiveness of pipeline works when carrying out marine orders. The chart of modeling the system of pipelines is presented. A straight pipe manufactured with an allowable deflection on a flat support and a loose flange attached to the end of the welded pipe are shown. The scheme of a permissible deviation α at mounting the connections between pipes is considered. The possibility of assembling curved pipelines using straight pipe sections is described in detail. The compensation zone is illustrated using the rotation of two pairs of deflected straight pipes. A block diagram of the application of research results in manufacturing and mounting a pipeline system has been developed

Geometry and Flow Properties Affect the Phase Shift between Pressure and Shear Stress Waves in Blood Vessels

The phase shift between pressure and wall shear stress (WSS) has been associated with vascular diseases such as atherosclerosis and aneurysms. The present study aims to understand the effects of geometry and flow properties on the phase shift under the stiff wall assumption, using an immersed-boundary-lattice-Boltzmann method. For pulsatile flow in a straight pipe, the phase shift is known to increase with the Womersley number, but is independent of the flow speed (or the Reynolds number). For a complex geometry, such as a curved pipe, however, we find that the phase shift develops a strong dependence on the geometry and Reynolds number. We observed that the phase shift at the inner bend of the curved vessel and in the aneurysm dome is larger than that in a straight pipe. Moreover, the geometry affects the connection between the phase shift and other WSS-related metrics, such as time-averaged WSS (TAWSS). For straight and curved blood vessels, the phase shift behaves qualitatively similarly to and can thus be represented by the TAWSS, which is a widely used hemodynamic index. However, these observables significantly differ in other geometries, such as in aneurysms. In such cases, one needs to consider the phase shift as an independent quantity that may carry additional valuable information compared to well-established metrics.

High-Pressure Piping

Chapter IX of ASME B31.3 only applies when the owner specifies its use. It applies to piping in High-Pressure Fluid Service. Note that the definition of High-Pressure Fluid Service simply requires that the owner specify use of Chapter IX. Some guidance is provided in FK300, which states “Although High Pressure Fluid Service is often considered to be service exceeding that allowed by the ASME B16.5, Class 2500 pressure-temperature rating for a particular material group, there are no pressure limitations for the application of these rules.” This is not a requirement, and the base Code may be satisfactorily used at pressures higher than ASME B16.5, Class 2500. However, the base Code rules become increasingly conservative and, in fact, impossible to use as the pressure approaches the allowable stress (including quality factors). See Section 17.3 for a discussion of pressure design of straight pipe. By the same token, Chapter IX may be used at lower pressures; it has been used with high-strength steels with pressures as low as 28,000 kPa (5,000 psi).

ANALISIS EFEKTIVITAS PENUKAR KALOR PIPA HELIKAL DESTILASI MINYAK ATSIRI KAYU PUTIH

The Eucalyptus plant is one of the essential oil-producing plants. Eucalyptus oil processing generally uses the distillation method. Traditionally used eucalyptus oil distillation uses a straight pipe condenser. The weakness of the straight pipe condenser is that the temperature of the condensate that comes out is still very high, this shows that the effectiveness of the straight pipe condenser is not optimal. To optimize the effectiveness of the distillation system condenser, a condenser with a helical pipe type condenser is designed in the essential oil distillation system. This study will vary the ratio of the pitch distance to the diameter of the condenser pipe, which aims to obtain an effective helical coil pitch ratio to optimize the effectiveness of the helical pipe condenser. This study uses the simulation method on COMSOL Multiphysics 5.4. The pitch ratio variant used is 2.1; 2.62; 3.15; 3.67; 4.2. The parameters that are constant in this study are the inlet fluid temperature on the tube side 373 K, the inlet fluid temperature on the shell side 288 K, the fluid inlet velocity on the tube side 0.2 m/s, and the fluid inlet velocity on the shell side 1 m/s. The results of the simulation by varying the pitch ratio show that the effectiveness increases as the pitch ratio value decreases, where the highest effectiveness is shown at pitch ratio of 2.1 which 75.9% and the lowest effectiveness is shown to pitch ratio of 4.2 which 70.7%.

Study on Influence of Branch Connection That Affects to Design Length of Pressure Design Under External Pressure

Pressure design of straight pipe under external pressure is performed in accordance with ASME B31.3 and Section VIII, Division 1 of Boiler and Pressure Vessel Code. And design length of straight pipe shall be defined in accordance with UG-28 and UG-29. However, there is no specific guideline about the design length which includes branch connection in piping system. Even though the branch connection is not a stiffening component, calculated result shows that increased design length can be considered for piping including the branch connection compared to straight pipe. This paper presents the study result that shows a tendency depending on several geometry parameters (e.g. Ratio of a diameter of header pipe to a thickness of header pipe.) using elastic buckling analysis performed in accordance with ASME Boiler and Pressure Vessel Code, Section VIII, Division 2. In addition to the result, this paper compares the design length of straight pipe with that of piping system including the branch connection under about the same eigenvalue condition which is called as a “Buckling load multiplier”. Shell element is enough to check the tendency and compare various results by comparison with solid model, because the result is related to overall structural integrity rather than local stress. Shell element is used in the elastic buckling analysis.