Considering Hydrotest Pressure Loading in the Calculation of MAWP of a Pressure Vessel

2021 ◽  
Author(s):  
Suresh K. Nawandar
Keyword(s):  
Pressure Vessel ◽  
Maximum Pressure ◽  
Pressure Loading ◽  
Working Pressure ◽  
Test Pressure ◽  
Considerable Impact ◽  
Static Head ◽  
The Impact ◽  
Design Pressure

Abstract As defined in UG-98 of the Code, the Maximum Allowable Working Pressure (MAWP), is the maximum pressure permissible at the top of the vessel in its normal operating position. It is the least of the values calculated for each of the vessel part adjusted for the static head and by including the effect of any combination of loadings listed in UG-22 of the Code. Conventional method of calculating the MAWP is to consider only the main pressure parts viz., the shells and the heads and the significant UG-22 loading viz., the wind and the seismic. Once the MAWP is determined, the rest of the vessel design is completed considering this value of MAWP as design pressure combined with any other applicable UG-22 loading. At the end, the vessel is verified for its adequacy to the test condition. It is noted that, the MAWP obtained through this method is often higher than the design pressure thus leading to the overdesign of the vessel. Moreover, higher MAWP results in higher test pressure, which might have a considerable impact of its own on the design of the vessel. The objective of this paper is to propose a design approach in which the test pressure itself is included as one of the governing loads in the determination of the MAWP so that the impact on vessel design, as explained above, is minimized.

The effect of proof testing on the shakedown behaviour of pressure vessel nozzles

1994 ◽  
Vol 29 (2) ◽  
pp. 81-92 ◽  
Author(s):  
N I Crawley ◽  
D N Moreton ◽  
D G Moffat ◽  
A F Tolley
Keyword(s):  
Stainless Steel ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Steel Type ◽  
Pressure Cycling ◽  
Proof Testing ◽  
Pressure Tests ◽  
Test Pressure ◽  
Design Pressure

Cyclic internal pressure tests were conducted over several hundreds of cycles at pressures up to and in excess of the calculated proof test pressure on two nominally ‘identical’, stainless steel type 316 flush 90 degrees pressure vessel nozzles, designed and manufactured to BS 5500. Prior to this pressure cycling, one vessel was subjected to the required proof test of 1.25 times the design pressure. Significant incremental straining was recorded in the non-proof tested vessel during cycling at all pressures above the first yeild pressure (0.336 × design pressure). For the proof tested vessel significant incremental straining was not recorded during cycling until 15 percent above the design pressure.

Elastic-Plastic Computations as a Basis for Design Charts for Torispherical Pressure Vessel Ends

1970 ◽  
Vol 185 (1) ◽  
pp. 869-877 ◽  
Author(s):  
C. H. A. Townley ◽  
G. E. Findlay ◽  
A. M. Goodman ◽  
P. Stanley
Keyword(s):  
Pressure Vessel ◽  
Master Curves ◽  
Elastic Plastic ◽  
Codes Of Practice ◽  
Design Charts ◽  
Starting Point ◽  
Test Pressure ◽  
Design Factors ◽  
Design Stress ◽  
Design Pressure

A series of elastic-plastic calculations has been carried out on torispherical drumheads subject to internal pressure. From the results of this analysis, master curves have been prepared which are independent of factors such as the ratio of design stress to yield stress and the ratio of design pressure to test pressure. These curves provide a rational starting point, from which Code Drafting Committees can derive, in simplified form where necessary, design factors to meet the requirements of specific Codes of Practice. An example of this use of the master curves is included. Correlation between the theoretical analysis and the available experimental data on torispherical drumheads is shown to be good. Conversely, the experimental results show that drumheads designed using factors derived from the master curves will perform satisfactorily in service. The principles illustrated in this paper can be applied to many other types of component commonly used in the pressure vessel industry. In this way, it is possible to provide a series of master curves which would form a rational basis, common to all codes, for the preparation of detailed design rules.

Effect of Steering Gear Parameters of Crawler Tractor Cornering Ability

2016 ◽  
Vol 20 (2) ◽  
pp. 159-169
Author(s):  
Cheslav Zhdanovich ◽  
Michail Mamonov ◽  
Maciej Kuboń ◽  
Jan Radosław Kamiński
Keyword(s):  
Maximum Pressure ◽  
Hydraulic Motor ◽  
Hydraulic Pump ◽  
Working Pressure ◽  
Oil Pump ◽  
Power Regulation ◽  
Drive Speed ◽  
Dry Soil ◽  
Turning Radius ◽  
The Impact

AbstractCrawler tractor with specific loads on the hitch loses traction abilities during cornering and causes intensive destruction of the surface layer of soil. This phenomenon may be limited if relevantly selected parameters of the cornering mechanisms were applied. The objective of the paper was to determine the impact of the cornering mechanism parameters on the crawler tractor maneuver ability. The object of the research was a planetary cornering mechanism which enables fluent change of the cornering radius through the change of the rotational speed of planetary gears drive by pneumatic engines. Relations of the turning radius to the slip of the spinning and overleaping crawler at the speed of 7 km·h-1 without the load on the hitch and with the load of 40 kN were defined. The average values of drift and the turning radius as a function of drive speed from 0 to 2.5 m·s−1 on the moist soil μ=0.4 and dry soil μ=0.8 were determined. Relations of the turning radius to the pressure of oil pump oil, to the drive speed and to the load on the hitch were set forth. The research proved that when using the hydraulic pump with the regulated expense the working pressure of oil may be maximally reduced to 30 MPa, the power of the pump may be reduced by twofold, the possibility of turning in difficult field conditions within the scope of the required speed may be enabled. To ensure the required turning radius of the crawler tractor it is recommended to install the pump with the efficiency of 33 cm3·rot−1 and a regulated hydraulic motor with the capacity of 56 сm3·rot−1 with a power regulation within 2.0-2.5, at the same time maximum pressure of liquid will not exceed 35 MPa and the determined power of the hydraulic gear will amount to 52.6 kW.

The Features of the Integrated Multilayer-Wrapped High Pressure Vessel and its Fabrication Quality being Inspected by Hydrostatic Test

2011 ◽  
Vol 201-203 ◽  
pp. 1539-1543
Author(s):  
Peng Yun Song ◽  
Yang Yong ◽  
Wang Zhong ◽  
Weng Yu ◽  
Ming Fu Hu ◽  
...  
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Circumferential Stress ◽  
Special Kind ◽  
Outer Shell ◽  
Solid Shell ◽  
High Pressure Vessel ◽  
Test Pressure ◽  
Synthetic Reaction ◽  
Design Pressure

The integrated multilayer-wrapped high pressure vessel is a special kind of multilayered pressure vessel whose circumferential weld seams are able to be in an offset pattern. The fabrication quality is assured by controlling the gaps of the layers. The tightness of the wrapped layers can be inspected by the hydrostatic test. The stress at the outer shell of a DN1400 urea synthetic reaction tower of the integrated multilayer-wrapped has been measured at the time of the hydrostatic test. The results show that the longitudinal stress is identical to that of the theoretical value, and the ratio of the measured circumferential stress to the theoretical calculated one of the corresponding solid shell vessel is more than 0.5 when the hydrostatic test pressure reaches the design pressure. The averaged ratio of the measured circumferential stress to the theoretical calculated one is 0.61 of the two measured sections at the hydrostatic test pressure of 20 MPa. The conclusions are: (1) the fabrication quality of the integrated multilayer-wrapped high pressure vessel are able to be assured, and (2) the tightness of the wrapped layers can be inspected by measuring the circumferential stress at outer shell, and compared to that of the theoretical value of the corresponding solid shell vessel, and (3) it is realizable that the circumferential stress at outer shell of the multilayer-wrapped vessel being not less than 50% of that of the theoretical calculated one of the corresponding solid shell vessel at the design pressure.

Strength of Thick-Walled Pressure Vessels for Materials With Directional Properties

1962 ◽  
Vol 84 (2) ◽  
pp. 197-202
Author(s):  
A. E. Dapprich ◽  
Joseph Marin ◽  
Tu-Lung Weng
Keyword(s):  
Tensile Stress ◽  
Pressure Vessel ◽  
Anisotropic Material ◽  
Pressure Vessels ◽  
Maximum Pressure ◽  
Closed Solution ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Cylindrical Pressure Vessel

This paper develops a theory for the determination of the plastic pressure-deformation relation in a thick-walled cylindrical pressure vessel subjected to internal pressure and made of an anisotropic material. In this theory, large or finite strains are considered and a closed solution is found for the pressure-strain relation based on a modified log-log tensile stress-strain relation. Theory is also developed for predicting the maximum pressure which the vessel can withstand.

Design and Analysis of an Ash Collector Hopper

2008 ◽  
Author(s):  
Bikramjit S. Antaal ◽  
Yogeshwar Hari
Keyword(s):  
Finite Element ◽  
Maximum Pressure ◽  
Complete Model ◽  
Boiler Plant ◽  
Finite Element Software ◽  
Design Load ◽  
Water Based ◽  
Design Values ◽  
Static Head ◽  
Design Pressure

This paper addresses the design and analysis of a hopper for ash collection in a Boiler Plant. The hopper collects the ash blown from the boiler soot blowers. The objective is to establish the design load. The design load is decided on the basis of the two cases. Case 1 Hopper full of ash Case 2 Hopper full of water. Based on the two cases the maximum pressure is considered as the design load. Also the hopper has a static head of gas pressure. The combinations of these are considered as design pressure. A typical hopper is taken. The thickness of the plate is decided. Then a procedure is developed to size the spacing and size of the stiffeners. The stiffeners used are Wide Flange I-beams. The hopper is modeled using STAAD III Finite Element Software. Two models are considered. First with one side of hopper. Second, complete model of the hopper. The stresses obtained are compared with the design values. The design of the hopper with analytical means is verified with Finite Element modeling of the two models considered.

Assessment of sensitivity of the efficiency of regional tax spending towards investment attractiveness of the types of economic activity carried out by the residents of advanced development territory

2020 ◽  
pp. 98-110
Author(s):  
Evgeniya Mikhailovna Popova ◽  
Guzel Mukhtarovna Guseinova ◽  
Sergei Borisovich Milov
Keyword(s):  
Economic Activity ◽  
Socioeconomic Development ◽  
Federal District ◽  
Tax Incentives ◽  
Capital Investments ◽  
The Subject ◽  
Investment Process ◽  
The Impact ◽  
Advanced Development

The deficit of subnational budgets and deceleration capital investments in multiple Russian regions increase the relevance of research aimed at improvement of tax incentivizing practice of the regional investment process. The studies focused on determination of the impact of socioeconomic and institutional factors upon the efficiency of investment tax expenses obtained wide circulation within the foreign scientific literature. The subject of this article is the assessment of sensitivity of the efficiency of regional tax expanses towards investment attractiveness of the types of economic activity carried out by the residents of territories of advanced socioeconomic development, created in the subjects of Far Easter Federal District. The scientific novelty and practical values of this research consists in substantiation of the reasonableness of assessment of investment attractiveness of the types of economic activity that are stimulated by tax incentives. Methodology for assessing investment attractiveness is proposed and tested. The conclusion is made that in case of low investment attractiveness of the type of economic activity, which was planned to support by tax incentives, it is required to conduct and additional analysis to avoid unjustified tax expanses.

Method development for the determination of textural properties of sugar beet roots

2019 ◽  
pp. 392-400 ◽  
Author(s):  
Gunnar Kleuker ◽  
Christa M. Hoffmann
Keyword(s):  
Sugar Beet ◽  
Compression Test ◽  
Storage Period ◽  
Textural Properties ◽  
Small Sample ◽  
Root Tip ◽  
Flexural Test ◽  
Sample Distribution ◽  
The Impact

The harvest of sugar beet leads to root tip breakage and surface damage through mechanical impacts, which increase storage losses. For the determination of textural properties of sugar beet roots with a texture analyzer a reliable method description is missing. This study aimed to evaluate the impact of washing, soil tare, storage period from washing until measurement, sample distribution and number of roots on puncture and compression measurements. For this purpose, in 2017 comprehensive tests were conducted with sugar beet roots grown in a greenhouse. In a second step these tests were carried out with different Beta varieties from a field trial, and in addition, a flexural test was included. Results show that the storage period after washing and the sample distribution had an influence on the puncture and compression strength. It is suggested to wash the roots by hand before the measurement and to determine the strength no later than 48 h after washing. For reliable and comparable results a radial distribution of measurement points around the widest circumference of the root is recommended for the puncture test. The sample position of the compression test had an influence on the compressive strength and therefore, needs to be clearly defined. For the puncture and the compression test it was possible to achieve stable results with a small sample size, but with increasing heterogeneity of the plant stand a higher number of roots is required. The flexural test showed a high variability and is, therefore, not recommended for the analysis of sugar beet textural properties.

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