Simple Discussion on Reliability Design of Mechanical Strength of Pressure Vessel

2021 ◽  
2011 ◽  
Vol 199-200 ◽  
pp. 559-563 ◽  
Author(s):  
Guang Zhong Hu ◽  
Liang Dong Zhang ◽  
Zhong Bin Liu ◽  
Kang Liu

Petrochemical pressure vessel equipment develops to be large-scale and super large-scale under extreme working conditions such as high temperature and high pressure, which puts forward new demands for the reliability of the pressure vessel. The present paper discusses the fatigue design theory of pressure vessels and analyzes the fatigue design methods of ASME, BS5500 and JB4732. Pressure vessel loads absorbed (pressure, temperature, earthquake, wind, snow, etc.) have significant stochastic dynamic characteristics and coupling characteristics. The random load of the current design is simplified, with a large safety factor in exchange for equipment safety. However, it is difficult to guarantee the rationality and accuracy of the result. With the development of data acquisition, processing and finite element technology, it is inevitable to be based on measured load spectrum and consider the coupling of the random loads to work out fatigue reliability design methods of pressure vessels.


2007 ◽  
Vol 353-358 ◽  
pp. 1239-1242
Author(s):  
Jun Shen ◽  
Huai Qin Xie

To meet the high reliability of structural design and safety evaluation on carbon fiber wound reinforced polymeric (CFWRP) pressure vessel, the traditional safety factor design was substituted by reliability design based on the reliability theory and statistical principle. Eight CFWRP pressure vessels were manufactured with the same material system by the same winding technique. And experiments were conducted to obtain the probabilistic distributions of design variables. Results derived from reliability design (fiber thickness) agreed well with experimental results and were much lower than that from conventional design. Through comparison among reliability design results with different statistics of fiber strength, significant effect of the variation of fiber strength on structural reliability of composite pressure vessel was demonstrated. The conventional design was verified to be not reasonable since it considers only the mean value of fiber strength without the effect of fiber strength distribution on structural resistance of pressure vessel.


Author(s):  
Avilash Carpenter ◽  
M.K. Gupta ◽  
Neetesh Kumar Jain ◽  
Urvashi Sharma ◽  
Rahul Sisodiya

Aim: The main of the study is to formulate and develop orally disintegrating fast dissolving tablet of Metoclopramide hydrochloride. Material & Methods: Before formulation and development of selected drug, the standard curve in buffer was prepared and absorbance at selected maxima was taken. Then two different disintegrating agents were selected and drug was mixed with disintegrating agents in different ratio. Various Preformulation parameters and evaluation of tablet i.e. disintegration time, dissolution time, friability, hardness, thickness were measured by standard procedure. Result & Discussion: The angle of repose for all the batches prepared. The values were found to be in the range of 30.46 to 36.45, which indicates good flow property for the powder blend according to the USP. The bulk density and tapped density for all the batches varied from 0.49 to 0.54 g/mL and 0.66 to 0.73, respectively. Carr’s index values were found to be in the range of 23.33 to 25.88, which is satisfactory for the powders as well as implies that the blends have good compressibility. Hausner ratio values obtained were in the range of 1.22 to 1.36, which shows a passable flow property for the powder blend based on the USP. The results for tablet thickness and height for all batches was found to range from 4.45 to 4.72 mm and 3.67 to 3.69 mm, respectively. Hardness or breaking force of tablets for all batches was found to range from 32.8 to 36.2 N. Tablet formulations must show good mechanical strength with sufficient hardness in order to handle shipping and transportation. Friability values for all the formulations were found to be in the range of 0.22 % to 0.30 %. Conclusion: Orally disintegrating tablets were compressed in order to have sufficient mechanical strength and integrity to withstand handling, shipping and transportation. The formulation was shown to have a rapid disintegration time that complied with the USP (less than one minute). The data obtained from the stability studies indicated that the orally disintegrating mini-tablets of MTH were stable under different environmental storage conditions. Keywords: Formulation & Development, Fast Dissolving Tablet, Metoclopramide, Anti-Emetic Drug, Oral Disintegrating Tablet


2011 ◽  
Vol 131 (8) ◽  
pp. 992-999 ◽  
Author(s):  
Tomoyuki Shoji ◽  
Shuichi Nishida ◽  
Toyokazu Ohnishi ◽  
Touma Fujikawa ◽  
Noboru Nose ◽  
...  

2003 ◽  
Vol 766 ◽  
Author(s):  
Raymond N. Vrtis ◽  
Mark L. O'Neill ◽  
Jean L. Vincent ◽  
Aaron S. Lukas ◽  
Brian K. Peterson ◽  
...  

AbstractWe report on our work to develop a process for depositing nanoporous organosilicate (OSG) films via plasma enhanced chemical vapor deposition (PECVD). This approach entails codepositing an OSG material with a plasma polymerizable hydrocarbon, followed by thermal annealing of the material to remove the porogen, leaving an OSG matrix with nano-sized voids. The dielectric constant of the final film is controlled by varying the ratio of porogen precursor to OSG precursor in the delivery gas. Because of the need to maintain the mechanical strength of the final material, diethoxymethylsilane (DEMS) is utilized as the OSG precursor. Utilizing this route we are able to deposit films with a dielectric constant of 2.55 to 2.20 and hardness of 0.7 to 0.3 GPa, respectively.


1986 ◽  
Vol 84 ◽  
Author(s):  
M.D. Merz ◽  
F. Gerber ◽  
R. Wang

AbstractThe Materials Characterization Center (MCC) at Pacific Northwest Lab- oratory is performing three kinds of corrosion tests for the Basalt Waste Isolation Project (BWIP) to establish the interlaboratory reproducibility and uncertainty of corrosion rates of container materials for high-level nuclear waste. The three types of corrosion tests were selected to address two distinct conditions that are expected in a repository constructed in basalt. An air/steam test is designed to address corrosion during the operational period and static pressure vessel and flowby tests are designed to address corrosion under conditions that bound the condi ring the post-closure period of the repository.The results of tests at reference testing conditions, which were defined to facilitate interlaboratory comparison of data, are presented. Data are reported for the BWIP/MCC-105.5 Air/Steam Test, BWIP/MCC-105.1 Static Pressure Vessel, and BWIP/MC-105.4 Flowby Test. In those cases where data are available from a second laboratory, a statistical analysis of interlaboratory results is reported and expected confidence intervals for mean corrosion rates are given. Other statistical treatment of data include analyses of the effects of vessel-to-vessel variations, test capsule variations for the flowby test, and oven-to-oven variations for air/steam tests.


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