Calculation for the selection of design pressure in pressure vessels with rupture discs
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When calculating the design pressure, for the manufacturing range of rupture discs, if an inverted arch shape is chosen, for example, if the operating pressure is 1 MPa, it is multiplied by 1.1; then, 1.1 × (1 + 0.05) = 1.155. Adding 0 gives 1.155 MPa. In the case of an inverted arch shape, would it be 1.0 × 1.7 = 1.7 MPa, followed by 1.7 × (1 + 0.015) = 1.7255, and then 1.7255 multiplied by (1 + 0.03) = 1.777265? So for GB150-2011.P19, for those values that don’t have a percent sign, should they be added directly or multiplied by (1+the value)?
This post was last edited by realme on 2012-8-19 at 23:48. One: It should be as follows: psmin ≥ 1.1 * pw = 1.1 * 1 Mpa = 1.1 Mpa. pb = psmin + the lower limit of the rupture disc’s manufacturing range = 1.1 + pb * 5%; here, half of this range is taken, with the lower limit being 5% of the design burst pressure and the upper limit being 0. pb = 1.1 / (1 – 0.05) = 1.1579 Mpa. p ≥ pb + the upper limit of the rupture disc’s manufacturing range = 1.1579 + 0 = 1.1579 Mpa. Therefore, the design pressure should be no less than 1.1579 Mpa. II: psmin ≥ 1.7 * pw = 1.7 * 1 Mpa = 1.7 Mpa. pb = psmin + the lower limit of the range for burst disc manufacturing = 1.7 + pb * 1.5%; here, half of this range is taken, with the lower limit being 1.5% of the design burst pressure and the upper limit being 3% of the design burst pressure. pb = 1.7 / (1 – 0.015) = 1.72589 Mpa. p ≥ pb + the upper limit of the range for burst disc manufacturing = 1.72589 * (1 + 3%) = 1.77767 Mpa. Therefore, the design pressure should be no less than 1.77767 Mpa. III: For those without a percent sign, as explained in point c) of b5.5 in 150.1, simply add it (take the absolute value).
Calculation of the design pressure for rupture discs in chemical process pressure vessels and an introduction to their types: http://bbs.hcbbs.com/thread-1633472-1-1.html (Source: Haichuan Network)
pb=1.1/(1-0.05)=1.1579Mpa. Could you explain why it is 1.1 divided by (1-0.05)?