How does the multiplication factor and the attachment height z work when doing seismic load set up?

Question

It seems that when setting up seismic load cases, the attachment and building height don't always change the g factors. Is the multiplication factor a safety factor depending on location, hazard, criticality, etc? If you use the appropriate building and attachment height and leave the mf as 1, would you comply with the ASCE code location as input into the seismic load case? 
 Should I be using both the mf and height inputs? Does Autopipe look at both and pick the worst case? 
 
 Thank you

Mike Dattilio · Accepted Answer

Greetings, 
 I believe that you are talking about the multiplication factor (f) at the bottom of the dialogs (see image below, what the arrows are point towards): 
 
 Whenever you have a question related to a dialog field in AutoPIPE, press the F1 key on your keyboard to see specific information. 
 In this case pressing F1, while the cursor is in that specific dialog field shows the following: 
 Multiplication Factor (f) 
 This factor is an AutoPIPE-specific value that may be used to simulate the amplified acceleration experienced by the piping component higher than the ground level. Default value is 1.0 and must be greater than 0.0. 
 As mentioned, this is an AutoPIPE specific value added to the code calculation, from program help: 
 
 To state the obvious, any value other than 1.00 will change the code calculated load case. 
 To answer your question specifically when to or when not to use this is feature? Answer, that is entirely up to you. Some of users want the ability to include a load the XX% more / less than code requirements. If you are not one of them, then leave the default value of 1.0. 
 Regards, Mike Dattilio Design Analysis Engineering Group Senior Analyst Bentley Systems Inc =============================================================================