5.4　Design Calculations

5.4.1　Unless otherwise specified，the design loads for trays shall be as specified in Table 5.4.1.

Table 5.4.1　Design load for trays

Table 5.4.1（Continued）

5.4.2　The stress and deflection of tray floor and support beam shall be calculated in accordance with Table 5.4.2-1.

Table 5.4.2-1　Calculation for stress and deflection of tray floor and support Beam

Table 5.4.2-2　Coefficients α，β，λ

5.4.3　In mechanical calculation of corroded parts of the tray based on the design load under operating conditions，their maximum bending stress（σM）shall not exceed the allowable stress at operating temperature as defined in GB 150 or JB/T 4756.

5.4.4　In mechanical calculation of corroded component parts of the tray based on the design load under installation or maintenance condition，the maximum bending stress（σM）shall not exceed 0.9 times the yield strength at ambient temperature as defined in GB 150 or JB/T 4756.

5.4.5　The mass load of tray floor shall be calculated assuming no holes in the tray floor，but calculation for stress and deflection of tray floor shall consider the weakening factor for all holes.

5.4.6　Unless otherwise specified，the maximum allowable deflection for the corroded component parts of the tray carrying design loads under normal operating conditions shall comply with the following requirements:

a）The maximum allowable deflection for one single tray floor shall not be greater than 3mm.

b）The allowable deflection for the support beam shall be as specified in Table 5.4.6.

c）The allowable deflection for any component served as a beam（e.g.，seal pan，downcomer，etc.）or the beam integrated to tray floor shall be as specified in Table 5.4.6 as well.

Table 5.4.6　Maximum allowable deflection for support beam　（unit:mm）