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Maximum Allowable Pressure calculating

For q - 0 or Tb -> 0, Ucond - 0, and at q - <=° or xb -> <=°, Ucond -> u. That is, to increase the filter capacity, filtration time should be increased. However, such an increase is limited by the maximum allowable pressure drop which at constant operating conditions, establishes a maximum cake thickness. Let s consider the following example for the first case in this analysis. We wish to determine the capacity of a batch filter operating at a constant rate. The rate of filtration is q = 0. 1 X 10 3 m3/m2-s and the auxiliary time is 900 s. The solution to this problem is as follows. The filter capacity is characterized by the average conditional filtration rate, q. Values of ucord calculated are shown plotted in Figure 41. As shown, an increase in the amount of filtrate causes a sharp increase in filter capacity initially, with a limiting value of u attained eventually. [Pg.397]

Here Nc stands for the total number of columns in the SMB plant. This procedure leads to higher pressure drops than in the real plant, since section I is the part of the process where, in general, the highest flow rate occurs. As demonstrated later, is not necessary to fix the flow rate in section I to the maximum allowed pressure drop to achieve optimal process performance. However, for a given flow rate in section I and all dimensionless flow rate ratios mj, the switching time can be calculated according to Eq. 7.78. [Pg.355]

The permanent deflection and burst methods of these alternative testing procedures are typically conducted at room temperature and, hence, provide maximum allowable pressure ratings for a vessel when used at room temperature. The corresponding pressure rating at an elevated temperature may be established by multiplying the calculated room temperature rating... [Pg.1248]

Maximum Allowable Pressure (MAP) Not an ASME Code requirement or definition. This is an optional pressure that was historically used as a basis for calculating test pressures. The MAP is the maximum pressure allowed in the new and cold condition (N C). This is calculated from the ASME equations using the new nominal thickness and the allowable stress at ambient temperature. [Pg.762]

From Equation 3-22 and knowing the yield strength of the material to be 6,000 psi, the maximum allowable pressure is calculated to be 1,590 psi. This is far above the 100-psi design pressure, so there is little chance of the pipe s failing. [Pg.189]

If the feedwater flow rate is assumed to be 25% (which is the same as that of constant pressure FPPs), the flash tank length should be greater than 3.6 m while the flash tank diameter should be about 3.4 m. The shell thickness t is calculated from the maximum allowable pressure P and the maximum allowable stress S by the following formula ... [Pg.278]

The maximum allowable internal pressure for multiple miter bends shall be the lesser value calculated from Eqs. (10-96) and (10-97). These equations are not applicable when 0 exceeds 22.5°. [Pg.985]

When the maximum vapor-relieving requirement of the flare system has been established and the maximum allowable back pressure (as just described) has been defined, line sizing reduces to standard flow calculations. [Pg.324]

If more than one standard pipe size is indicated, calculate the wall thickness for each standard pipe size based on required maximum allowable working pressure and select a standard wall thickness for each -Size. [Pg.447]

Stinton (1983) and Lees (1980) describe this accident. On July 11, 1978, at 12 05 P.M., the loading of a tank truck with propylene was completed. According to weight records obtained at the refinery exit after loading, it had been grossly overloaded head space was later calculated to be inadequate. The truck scale recorded a weight for the load of 23,470 kg (52,000 lb)—well over the maximum allowable weight of 19,099 kg (42,000 lb). The tank truck was not equipped with a pressure relief valve. [Pg.42]

In accidental releases, pressure within a vessel at time of failure is not always known. However, depending on the cause of vessel failure, an estimate of its pressure can be made. If failure is initiated by a rise in initial pressure in combination with a malfunctioning or inadequately designed pressure-relief device, the pressure at rupture will equal the vessel s failure pressure, which is usually the maximum allowable working pressure times a safety factor. For initial calculations, a usual safety factor of four can be applied for vessels made of carbon steel, although higher values are possible. (The higher the failure pressure, the more severe the effects.)... [Pg.225]

A rough approximation of operating mesh pressure drop is 1 inch water or less. The calculated pressure drop at the maximum allowable velocity is close to 1.5 inches of water. Therefore ... [Pg.248]

Maximum Allowable Working Pressure (MAWP) the maximum pressure pounds per square inch gauge permissible at the top of a completed vessel in its operating position for a specific designated temperature corresponding to the MAWP pressure. This pressure is calculated in accordance with the ASME code (Par. UG-98) [1] for all parts or elements of the vessel using closest next larger to calculated value nominal thickness (closest standard for steel... [Pg.405]

Pressure vessels are subjected to other loads in addition to pressure (see Section 13.4.7) and must be designed to withstand the worst combination of loading without failure It is not practical to give an explicit relationship for the vessel thickness to resist combined loads. A trial thickness must be assumed (based on that calculated for pressure alone) and the resultant stress from all loads determined to ensure that the maximum allowable stress intensity is not exceeded at any point. [Pg.831]

The oil-water dynamic interfacial tensions are measured by the pulsed drop (4) technique. The experimental equipment consists of a syringe pump to pump oil, with the demulsifier dissolved in it, through a capillary tip in a thermostated glass cell containing brine or water. The interfacial tension is calculated by measuring the pressure inside a small oil drop formed at the tip of the capillary. In this technique, the syringe pump is stopped at the maximum bubble pressure and the oil-water interface is allowed to expand rapidly till the oil comes out to form a small drop at the capillary tip. Because of the sudden expansion, the interface is initially at a nonequilibrium state. As it approaches equilibrium, the pressure, AP(t), inside the drop decays. The excess pressure is continuously measured by a sensitive pressure transducer. The dynamic tension at time t, is calculated from the Young-Laplace equation... [Pg.367]

The maximum allowable internal pressure for a single miter bend with angle 0 not greater than 22.5 deg shall be calculated by eq. (4a). [Pg.93]

Singh s method 101 allows some account to be taken of material loss through the relief system as the pressure rises from the relief pressure to the maximum accumulated pressure. An average rate of gas generation is used in the derivation (i.e. between that at the relief pressure and the peak rate for the reaction). This is intended to ensure that the method remains conservative, even though account is taken of material loss. The method allows the relief area calculated by the DIERS equation to be reduced by up to a factor of 3 ... [Pg.180]

This is the continuation of Worked Example 3.1. If there is loss of control of an amination reaction, the temperature could reach 323 °C (MTSR), but the maximum allowed working pressure of 100 bar g would be reached at 249 °C (MTT). Thus, the question is If the reaction can be controlled by depressurizing the reactor before the safety valve opens, that is, before 240 °C is reached, what would the vapor release rate be To answer this question, information about the reaction kinetics is required. The only information is that at 180°C, a conversion of 90% is reached after 8 hours. If we consider the reaction to follow a first-order rate equation, justified by the fact that ammonia is in large excess, we can calculate the rate constant at 180 °C ... [Pg.250]

Maximum allowable working pressure (MAWP) The maximum permissible gauge pressure of a vessel in its operating position at a designated temperature. The pressure is based on calculations for each element in a vessel, using nominal thickness exclusive of additional metal thickness allowed for corrosion. The MAWP is the basis for the upper limit of pressure setting of the safety relief devices that protect the vessel (see Section 3.6). [Pg.49]


See other pages where Maximum Allowable Pressure calculating is mentioned: [Pg.397]    [Pg.11]    [Pg.448]    [Pg.11]    [Pg.303]    [Pg.355]    [Pg.240]    [Pg.199]    [Pg.472]    [Pg.483]    [Pg.28]    [Pg.2282]    [Pg.2301]    [Pg.237]    [Pg.331]    [Pg.556]    [Pg.451]    [Pg.451]    [Pg.196]    [Pg.359]    [Pg.93]    [Pg.93]    [Pg.45]    [Pg.94]    [Pg.170]    [Pg.180]   
See also in sourсe #XX -- [ Pg.29 ]

See also in sourсe #XX -- [ Pg.53 ]




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