Environmental effects on the mechanical properties of E-glass and S-glass fiber epoxy composite ring specimens used in aircraft fuel pipes

An experimental investigation was performed in predicting the consequences of the exposure to seawater and moisture absorption on the mechanical properties of two different GFRE pipe rings made of E-glass and S-glass fiber and utilized in aircraft fuel pipe line system. Filament winded tubular composite pipe rings were immersed in seawater for two, four and six months, respectively and their moisture absorption was noted. The outcomes exhibit a remarkable decrease in fatigue life for saturated GFRE sample rings. In contrast, a water absorption up to 40% of the maximum content exhibited no impact. The tests revealed debonding and cracks in the fiber and matrix interphase in the case of samples immersed in seawater on a long-term basis, although the applied mechanical load was zero.

Estimation of Super High-Rise Pumping Pressure for High-Performance Concrete Based on Computational Fluid Dynamics Modeling and Situation Measurement

Traditional methods fail to predict the pumping pressure loss of high-performance concrete properly in super high-rise pumping situations due to complex changes of concrete properties. Therefore, it is imperative to propose a relative accurate method for pumping pressure estimation in super high-rise buildings. This paper builds the simplified pressure calculation method “pressure induced by the gravity plus pressure along the pipe line.” The later one is gained by establishing topology optimized model based on computational fluid dynamics and considering the lubrication layer formation. The effect of rheological properties and flow rate is analyzed based on this model in detail. Furthermore, the developed calculation method is verified by the measured pumping pressure during the super high-rise building construction of the Shanghai Tower (the tallest building in China recently). The relative differences between the calculation results and the measured data in situ are less than 6%, indicating the applicability of this method for predicting the pressure loss of the super high-rise pumping.

Hydraulic transients for a pipe line network of treated effluent rising main using SAP 2R

Hydraulic transients occur as a direct result of rapid variations of flow field in pressurized systems. The change in velocity from valve closures or pump operations causes pressure surges that are propagated away from the source throughout the pipeline. The associated pressure changes during a transient period are quite large and occur quickly (within a few seconds). It should also be noted that when the maximum pressures exceed the bar ratings (mechanical strength) of the piping material, failure can occur. Similarly, if the minimum pressure drops below the vapour pressure of the fluid, cavitation can occur. The purpose of the present study is to model and simulate the hydraulic transients in a pipeline network system of treated effluent rising main of Mpophomeni sanitation scheme using SAP 2R. A total of five scenarios were simulated using different combinations. The simulation results show that the transient pressures in the pipeline exceeded the bar rating of the pipe where the bursts or cavitation may occur for the simulated scenario, but transient pressures were reduced to a safe limit after providing water hammer protection devices.

In-Line-Inspection (ILI) of a Pipeline in Constrained Condition and Establishing Integrity of the Pipeline

One 24” Diameter and around 40 km length Natural Gas pipeline caters as energy life line for Mumbai city; supplying app 4.5 MMSCMD Gas for Auto Sectors (CNG), House Hold (PNG), Power, Fertiliser, Petrochemical Sectors. Though line is equipped with Launcher & Receiver; but onward became challenging one for executing pigging for many constraints: - Presence of One SR bend - Presence of 1.5 D bends - Presence of 1.5 D bends with Back to Back configuration - Three (3) no Thermal Expansion Loops, in 2 Km stretch passing as above ground pipeline through bridge (above Creek) section The pipe line is passing through High Consequence areas, including its interim stretch of 2km passing as above ground section through bridge structure. Intelligent pigging is an obvious first preference for online precise integrity assessment for any pipeline. Site Specific Assessment, Detail Engineering & Committed approach resulted in Feasibility & Development of ILI Tool, Practical Testing in fore hand before actual pigging & onward Integrity Assessment of the pipeline conducted by accomplishing Successful ILI run.

Comparative study of a milking unit pulsation system in laboratory and field conditions

A comparative study of the pulsation phases in classic milking units was performed. The testing of the same is done in laboratory and field conditions (during milking). The pulsation settings at which the test was performed were pulsation rate 60 min-1 and 90 min-1, ratio 50/50% and vacuum mode 50 kPa. The experiments were performed in the laboratory of “Machine milking” (Department of Agricultural Engineering, Faculty of Agriculture, Trakia University) on a milking installation with a pipe line and on a farm for 60 lactating cows at the same milking installation. It was found that the transients (phases “a” and “c”) are significantly reduced during milking. Respectively, the actual phases (phases “b” and “d”) are significantly increased during the milking process. The conclusions are related to the settings and timely diagnostics of the milking machine.