50 % seismic loads in hydrotest case

[inammanj123]

Hi,

Im working on horizontal equipment, on saddles. As per my client requirement in hydrostatic case earthquake design load be reduced to 50 percent.

THE QUESTION IS THAT HOW CAN I MAKE SURE THAT SEISMIC PARAMETERS ARE REDUCED TO 50 PERCENT, I MEAN WHAT PARAMETER IN THE SEISMIC WINDOW I SHOULD CHANGE TO GET THE EFFECT OF 50 PERCENT SEISCIC LOADS.PLEASE NOTE THAT I HAVE FILLED THE VESSEL FULL WITH WATER AND USED HYDROTEST PRESSURE AS INTERNAL PRESSURE.

Currently Faliur is coming in " Thermal expansion base shear = W*m". Can any one tell me from where the value of "W"came from, because value of seismic shear force is 120249 N, whereas value of "W" used in this thermal expansion base shear formula is 458,785.17 N.
I think if i can reduce this value of "W" to 50 % my saddle can pass. Please tell what is this value of W and how can i reduce this value to so get 50 % of seismic effect

 

[Mech2325]

Well, as per my experience, compress does not calculate the seismic base shear in hydrotest case. It only calculates wind loads for this case. Your vessel seems to be failing for operating case. The value of "W" i had also been seeing as to from where does it come. What is your operating weight?? Maybe the "W" is the operating weight in "Newtons"