Erosive Wear Of Natural Gas Pipes Due To High Velocity Jet Impact: Physical Examination And Experimental Study

2012 ◽  
Author(s):  
Z. A. Majid ◽  
R. Mohsin ◽  
M. Z. Yusof
Keyword(s):  
High Pressure ◽  
Carbon Steel ◽  
High Speed ◽  
Experimental Testing ◽  
Water Jet ◽  
Gas Jet ◽  
Water Pipe ◽  
Pipe Surface ◽  
Jet Impact ◽  
Pressure Water

A sequential failure of API 5L X42 (NPS8) carbon steel and SDR 17 medium density polyethylene (MDPE) pipes towards the high pressure water pipe was studied. Pipe’s failed specimen was physically examined and experimental testing was conducted by using high speed water jetting facility towards a similar NPS8 pipe specimen. High pressure water jet impact from leaked water pipe forms highly erosive water–soil slurry and this caused severely damaged on NPS8 carbon steel pipe surface. Thus, causing substantial losses of pipe coating materials and subsequent rapid thinning of pipe body occurred. Furthermore, weaker ground support causes instability to the MDPE pipe and leads to vertical descend towards high speed gas jet region exerted from failed NPS8 pipe. High impact gas jet physically hit the MDPE pipe at its opposite direction causing its rapid erosion. Key words: Liquid impact erosion; gas jet impact; solid particle impact; water jet impact

Structure of Emulsion Cavitation Jet and Jet Peening Impact on the Fatigue of Plan Carbon Steel Q235A

2011 ◽  
Vol 189-193 ◽  
pp. 476-483
Author(s):  
Zhi Sun ◽  
Yan Wei Sui ◽  
Jun Li ◽  
Yan Ni Zhou
Keyword(s):  
Carbon Steel ◽  
High Speed ◽  
Test System ◽  
Water Jet ◽  
High Speed Photography ◽  
Strengthening Effect ◽  
Initial Stage ◽  
Jet Impact ◽  
Upstream Pressure ◽  
Crack Initiation Life

Due to developing the strengthening effect of liquid jet peening on the surface modification for metallic materials, in this study, an emulsion jet peening is produced by injecting a high-speed emulsion jet into an emulsion filled tank. The test system and fixed emulsion of cavitation jet was developed. High speed photography technique was used to observe and analysis the structure of emulsion cavitation jet at various upstream pressures . The results indicate that the structure of emulsion cavitation jet in terms of jet impact pressure, intensive degree and uniformity is better than that water jet. The jet structure depends on the jet pressure. The cavitation jet length increases rapidly at the initial stage and then it stabilizes after few milliseconds. The stabilized length of jet increases and the diverges angle decreases with increasing pressures. Specimens made of plan carbon steel (Q235A, China standard) were exposed to emulsion jet peening at the stand-off distances of 20 mm with a constant upstream pressure, 20 MPa for 60 s. The fatigue test shows that the crack initiation life by treatment of emulsion jet peening increases about 12.5% and 20.2% compared to water jet and unpeened specimen respectively.

scholarly journals Calculation Model of High-Pressure Water Jet Slotting Depth for Coalbed Methane Development in Underground Coal Mine

2019 ◽  
Vol 9 (23) ◽  
pp. 5250 ◽  
Author(s):  
Jianguo Zhang ◽  
Yingwei Wang ◽  
Zhaolong Ge ◽  
Songqiang Xiao ◽  
Hanyun Zhao ◽  
...  
Keyword(s):  
High Pressure ◽  
Rotation Speed ◽  
Initial Period ◽  
Calculation Model ◽  
Water Jet ◽  
Nozzle Diameter ◽  
Coal Seams ◽  
Jet Impact ◽  
Pressure Water ◽  
High Pressure Water Jet

In underground coal mines, high-pressure water jet slotting is effective at improving coal seams’ permeability. The slotting depth determines the effect of pressure relief and permeability enhancement in coal seams. However, there is no effective and feasible way of determining the slotting depth; thus, the operational parameters and borehole layout are unknown. This study determined the effects of key parameters, including the nozzle diameter, jet pressure, rotation speed, and slotting time, on the slotting depth. A water jet slotting depth calculation model was established and verified according to the slotting experiments under different operational conditions. The slotting depths were investigated based on the results of field slotting experiments. The results revealed that there exists an optimal nozzle diameter for a higher jet impact velocity. The slotting depth linearly increased with the jet pressure and decreased as a power function with the increase of the jet translation speed. The slotting depth increased with the slotting time, but the growth rate gradually decreased and tended to be stable. As the rotation speed increased, the slotting depth became greater at the initial period and the limit depth was reached faster. Laboratory and field slotting experiments were conducted to verify the model, and the experimental results are approximately in agreement with the theoretical predictions. The results of this study can be useful as guidelines for the hydraulic parameter selection of water jet slotting and for optimizing the layout of coal gas drainage boreholes.

The mechanism and application of high-pressure water jet technology to prevent compound dynamic disaster

2021 ◽  
Vol 14 (13) ◽  
Author(s):  
Zeng-qiang Yang ◽  
Chang Liu ◽  
Feng-shuo Li ◽  
Lin-ming Dou ◽  
Gang-wei Li ◽  
...  
Keyword(s):  
High Pressure ◽  
Water Jet ◽  
Pressure Water ◽  
Dynamic Disaster ◽  
High Pressure Water Jet

Crowning Carrots with a High Pressure Water Jet

1988 ◽  
Vol 4 (4) ◽  
pp. 340-343 ◽  
Author(s):  
John H. Posselius ◽  
Jr.. Glenn T. Conklin
Keyword(s):  
High Pressure ◽  
Water Jet ◽  
Pressure Water ◽  
High Pressure Water Jet
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