Here's another page from the same site where conventional aluminumbottles are offered.......http://wholesaler.alibaba.com/product-detail/0-5L-20mpa-Gas-cylinder-seamless_60189366821.html?spm=a2700.7765678.1998649852.5.kYJaEMA simple tangential stress calculation of the pictured unit using stress = pressure*ID/2*wall thicknessgives a value of ~18500 psi. The material listed is 6061 which has a minimum tensile strength of 45000 psi.The safety factor is therefore ~2.4 ........and yet the words "DOT certificate" appear at the bottom of the pic.Have I missed something here? Ron
Taken directly out of Appendix 1 of ASME II Part D:FOR SECTION VIII DIVISION 1 - The maximum allowable stress shall be the lowest valueobtained from the criteria in Table 1-100. The mechanicalproperties considered, and the factors applied to establishthe maximum allowable stresses, are as given below.(a) At temperatures below the range where creep andstress rupture strength govern the selection of stresses,the maximum allowable stress value is the lowest of thefollowing:(1) the specified minimum tensile strength at roomtemperature divided by 3.5(2) the tensile strength at temperature divided by 3.5(3) two-thirds of the specified minimum yieldstrength at room temperature(4) two-thirds of the yield strength at temperatureIn the application of these criteria, the Committee considersthe yield strength at temperature to be SYRY, and thetensile strength at temperature to be 1.1STRT.Two sets of allowable stress values are provided inTables 1A and 1B for austenitic materials and specificnonferrous alloys. The higher alternative allowable stressesare identified by a footnote to the tables. These stressesexceed two-thirds but do not exceed 90% of the minimumyield strength at temperature. The higher stress valuesshould be used only where slightly higher deformation isnot in itself objectionable. These higher stresses are notrecommended for the design of flanges or other strainsensitive applications.(b) At temperatures in the range where creep and stressrupture strength govern the selection of stresses, the maximumallowable stress value for all materials is establishedby the Committee not to exceed the lowest of the following:(1) 100% of the average stress to produce a creeprate of 0.01%/1,000 hr(2) 100Favg% of the average stress to cause ruptureat the end of 100,000 hr(3) 80% of the minimum stress to cause rupture atthe end of 100,000 hrStress values for high temperatures are based, wheneverpossible, on representative uniaxial properties of the materialsobtained under standard ASTM testing conditions orequivalent. The stress values are based on basic propertiesof the materials and no consideration is given for corrosiveenvironment, for abnormal temperature and stress conditions,or for other design considerations.FOR SECTION VIII DIVISION 2 - Design stress is the lower of:Min spec tensile strength / 2.4; Min spec yield strength / 1.5;OR(Min spec yield strength * temperature derating factor) / 1.5;
JDS airman reg. will fit. 4500/metric outputs up to 2400psi
Quote from: oldpro on May 20, 2016, 05:14:32 PMJDS airman reg. will fit. 4500/metric outputs up to 2400psiJDS airman reg. & bottles, it is Chinese?http://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20160520124127&SearchText=paintball+regulator
Quote from: Job on May 20, 2016, 05:44:48 PMQuote from: oldpro on May 20, 2016, 05:14:32 PMJDS airman reg. will fit. 4500/metric outputs up to 2400psiJDS airman reg. & bottles, it is Chinese?http://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20160520124127&SearchText=paintball+regulatorIs this a question?
Are they a good or bad copy of the original? Do they work ok?
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