Investigation of Clamp Design for Temporary Attachment to Metal Pipe

1990 ◽  
Vol 112 (1) ◽  
pp. 92-96
Author(s):  
J. A. Johnson ◽  
J. M. Henderson
Keyword(s):  
Comparative Study ◽  
Relative Motion ◽  
Axial Force ◽  
Steel Pipe ◽  
Worst Case ◽  
Operating Condition ◽  
Metal Pipe

A comparative study of different configurations of locator pads used to attach a portable piping lathe to a section of steel pipe was performed. The axial force exerted by adjustment screws attached to the locator pads was determined experimentally. The minimum axial force required to restrain relative motion between the lathe and the pipe during a worst case operating condition was used as a criterion to determine the effectiveness of a particular contact pad. Six different geometric variations and two different materials were investigated and it was found that aluminum, in a simple configuration, provided the best clamping capability.

Design Methodology for Axial Force Response of Pipe-in-Pipe: A Probabilistic Approach

2011 ◽  
Author(s):  
Olav Fyrileiv ◽  
Mark Marley ◽  
Sune Pettersen
Keyword(s):  
High Pressure ◽  
Axial Force ◽  
Probabilistic Approach ◽  
Design Approach ◽  
Electrical Heating ◽  
Buried Pipe ◽  
Worst Case ◽  
Operational Conditions ◽  
Offshore Development ◽  
Selection Of

As the easy oil is more or less gone, the typical offshore development faces several challenges in the future. These may be related to ultra deep water or difficult operational conditions like high pressure and temperatures. In addition there are often challenges related to flow, for example wax or hydrates during shut-downs or in tail production. Prevention of wax and hydrates is often solved by injection of chemicals or alternatively by some sort of heating, e.g. direct electrical heating. It may also to some degree be solved by superior thermal insulation or a combination of the methods mentioned. A thick insulation coating may give additional challenges with respect to submerged weight. Pipe-in-pipe (PIP) designs, where the flowline is insulated and covered by an outer pipe, solve this challenge and are becoming more and more popular. However, the pipe-in-pipe concepts also provide some specific challenges. DNV has recently been involved in a PIP project with quite challenging operational conditions. The combination of high temperature and high pressure (HTHP) and a corrosive well fluid with a buried pipe-in-pipe without any release of axial force leads to a very conservative design using conventional design approach. This challenge can be solved by applying a stochastic design approach avoiding conservative assumptions on top of each other. A probabilistic analysis targeting an acceptable probability of failure according to DNV-OS-F101 [1] resulted in an optimised design with a balanced selection of input parameters and avoiding ultra-conservative, worst case input combinations.

scholarly journals Role of Heuristic Algorithms in Minimizing the Makespan of Fuzzy Flow shop Scheduling Problem

2019 ◽  
Vol 8 (3) ◽  
pp. 821-826
Keyword(s):  
Comparative Study ◽  
Heuristic Algorithms ◽  
Flow Shop ◽  
Flow Shop Scheduling ◽  
Scheduling Problem ◽  
Worst Case ◽  
Shop Scheduling ◽  
Fuzzy Models ◽  
Sample Data

In this paper, the three fuzzy heuristics namely fuzzy Campbell-Dudek-Smith algorithm(FCDS), fuzzy NawazEnscore-Ham(FNEH) algorithm and fuzzy Rapid Access(FRA) algorithm has been subjected to a comparative study to evaluate and assess the efficiency of the fuzzy models in various problems of random size.A sample data is chosen and 14 problems are generated with different job and machine size.The makespan is evaluated,compared and depicted using ORIGIN software.The worst case solution of every problem is compared with the heuristic schedule obtained in order to show the improvement in the solution when the above heuristics are applied.It is noticed that the FNEH algorithm stand tall above the remaining procedures adopted in this work except a few instances where the FRA procedure excels.

scholarly journals Optical crossbars on chip, a comparative study based on worst-case losses

2014 ◽  
Vol 26 (15) ◽  
pp. 2492-2503 ◽  
Author(s):  
Sébastien Le Beux ◽  
Hui Li ◽  
Gabriela Nicolescu ◽  
Jelena Trajkovic ◽  
Ian O'Connor
Keyword(s):  
Comparative Study ◽  
Worst Case ◽  
On Chip

scholarly journals Comparison of in-situ delay monitors for use in Adaptive Voltage Scaling

2012 ◽  
Vol 10 ◽  
pp. 215-220 ◽  
Author(s):  
N. Pour Aryan ◽  
L. Heiß ◽  
D. Schmitt-Landsiedel ◽  
G. Georgakos ◽  
M. Wirnshofer
Keyword(s):  
Error Detection ◽  
Supply Voltage ◽  
Power Saving ◽  
Voltage Scaling ◽  
Worst Case ◽  
Operating Condition ◽  
Detection Approach ◽  
Test Circuit ◽  
Safety Margins

Abstract. In Adaptive Voltage Scaling (AVS) the supply voltage of digital circuits is tuned according to the circuit's actual operating condition, which enables dynamic compensation to PVTA variations. By exploiting the excessive safety margins added in state-of-the-art worst-case designs considerable power saving is achieved. In our approach, the operating condition of the circuit is monitored by in-situ delay monitors. This paper presents different designs to implement the in-situ delay monitors capable of detecting late but still non-erroneous transitions, called Pre-Errors. The developed Pre-Error monitors are integrated in a 16 bit multiplier test circuit and the resulting Pre-Error AVS system is modeled by a Markov chain in order to determine the power saving potential of each Pre-Error detection approach.

Comparative Study of the Machinability of a Sintered Steel and a Nodular Graphite Iron Using a Constant Axial Force Drilling Test

2006 ◽  
Vol 526 ◽  
pp. 49-54
Author(s):  
Lluis Costa Herrero ◽  
Cayetano Sierra Alcolea ◽  
Joan Vivancos Calvet
Keyword(s):  
Comparative Study ◽  
Axial Force ◽  
Steel Sample ◽  
Cutting Conditions ◽  
Sintered Steel ◽  
Maximum Production ◽  
Iron Sample ◽  
Optimum Cutting ◽  
Nodular Graphite

The objective of this study is to compare the machinability of a sintered steel sample with that of a nodular graphite iron sample. We have developed a method that not only allows us to study the machinability, but also enables us to determine the optimum cutting conditions to suit criteria for maximum production or maximum quality. The method is based on a drilling test using constant axial force at the tip of the drill.

scholarly journals Acceptance Criteria of Local Wall Thinning in Carbon Steel Pipe Subjected to Axial Force.

1991 ◽  
Vol 57 (539) ◽  
pp. 1470-1474 ◽  
Author(s):  
Kunio HASEGAWA ◽  
Satoshi KANNO ◽  
Akihiko HIRANO ◽  
Masayuki ISHIWATA ◽  
Nobuho GOTOH
Keyword(s):  
Carbon Steel ◽  
Axial Force ◽  
Steel Pipe ◽  
Acceptance Criteria ◽  
Wall Thinning ◽  
Local Wall Thinning
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