Number of hangers

Question

I want to change a constant spring for 2 variable springs, but when I change the number of hanger into the support input, and after I run the hanger selection procedure, Autopipe changes again the variable springs to a TWO constants supports and when I see the hanger report the constant support is there, the hot load is half, but I can't see what is the variable springs type that Autopipe selected, so, the questions are: 
 Does Autopipe select 2 spring variables springs or not? 
 Where can I check what support type Autopipe selected?

Mike Dattilio · Answer

Greetings, 
 See WIKI here , and review both the Cold and Hot load selection procedure. The program is looking for a spring that will handle the parameters given and the amount of movement / loading required. You can review the spring manufacture library data in AutoPIPE help. 
 Note, if you do not like the spring select by the program, please uncheck undesigned and enter your own spring values. 
 To answer your questions: 
 Q1. Does Autopipe select 2 spring variables springs or not? 
 Answer: 
 As indicated in the Cold/ Hot spring selection help information: 
 "If both the hot load and the cold load cannot be found within a spring size, then the next size is checked. If a single spring cannot be found, two hangers are assumed at this location and another pass is made through the hanger table (see example of manufacture's spring table below). 
 If no spring can be found which satisfies the preceding requirements, a constant force hanger is selected." 
 At this time, May 2023, one cannot enter different variables when "Number of Spring Hangers" is greater than 1. 
 Q2. Where can I check what support type Autopipe selected? 
 Answer: 
 The hanger report will provide the user information on which spring hanger satisfies the spring hanger selection process. Per your report image above, Node Point 216A, notice that AutoPIPE determined 3 different springs that satisfied the hanger selection. Note, there could be many more springs of each size that meet the requirements, however AutoPIPE will only list the first on in each size category. Furthermore, the actual spring used in the analysis is the 1st one with the star next to it. 
 Lastly, from the images provided, I am not able to tell exactly the intent of this spring, is the dialog hiding a nozzle? or is this just a support at the bottom of what looks to be a riser? You may consider an iterative process of using different supports with different stiffness to see how sensitive the stresses are in the area. 
 In closing recommend that you familiarize yourself with the hanger selection process to truly understand the process and remember AutoPIPE's hanger selection is just one suggestion of many possible solutions to resolving stresses in the model. 
 Regards, Mike Dattilio Design Analysis Engineering Group Senior Analyst Bentley Systems Inc =============================================================================