PV ELITE Effective gasket Width calculation 1

[Ronak_Patel]

I`m using SI units in PVelite .
As per ASME Div 1 , mandatory appendix 2 (2-3) value of cb=0.5 for US Customary and cb=2.5 for SI calculations .
While Reviewing Pv Elite design calculation of flange i found this ,

Gasket Contact Width, N = (Go - Gi) / 2 = 13.000 mm.
Basic Gasket Width, bo = N / 2 = 6.500 mm.
Effective Gasket Width, b = Cb sqrt(bo)= 6.425 mm.

if i use cb=2.5*sqrt(6.5)=6.37 , as such its not much of difference but which value should be followed?? ..
pvelite is first converting bo in inches then calculating b and converting it in mm to get 6.425mm

 

[Geoff13]

Per U-4, the Code expects all calculations to be done in a single system of units. I'm unfamiliar with PV Elite, but apparently it chooses to do all calculations in US Customary. As such it's value is correct.

The Code is not written with intent that the US Customary and SI values and formulas give identical results. It is best to think of it as two independent codes that happen to be printed in the same book. Choose one unit system and stick with it throughout. You will find small differences like your example in many calculations if you did each of them in both unit systems.

 

[Ronak_Patel]

Thank you @geoff13 for your reply.i had impression that it doesn't matter whether i choose SI or US customary , ans will be same but as you clarified they are two independent system and answers will slightly differ . I checked PVelite Uses US Customary as System UNITS to do calculations.Thank you!!