Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: Modeling Subarea: Original Author: Bentley Technical Support Group Attention: Please see the following AutoPIPE help section: Help Contents Contents Tab Modeling Approaches Modeling Approaches This help has been provided in order to give users ideas for modeling typical piping arrangements. The steps shown in each example should not be taken as the only method available to create models. In addition, the intent of the examples is to present ways to create adequate models of specific piping components for analytic purposes. Anchors Bends Cuts Flexible Joints Frames Hangers Nozzles Pipes Reducers Rotating Equipment Supports Tees Valves Vessels Comments, Questions, and Answers: Item #1: How to model a 3-way valve? Answer: Inputting three way valves in AutoPIPE is a bit convoluted at this time. AutoPIPE does not allow users to branch from a valve, see the following procedure: Divide the valve into 3 pieces, length and weight divided, and input them as separate valves, Put very short dummy runs of rigid pipe (select "rigid" as pipe data identifier) in between the valves and at the branch. Convert the run points to a Tee using the "convert run to tee" icon/button. See below what it should look like: Item #2: Valve Pressure rating drop-down list only shows NS (Non-Standard) Answer : Per the screen shot below, left Valve dialog is on 8" pipe, right Valve is on a 60 inch pipe. Note the image has only NS for Pipe Rating. the reason is because the pipe size is beyond that found in the current equipment library. Therefore only option available is to select a Pressure Rating = NS, and manually update the valve length. Item #3: How to model a complex valve such as a Bell & Gossett Triple Duty Valve in AutoPIPE? Answer : Modeling any type of valve in AutoPIPE is easy after the user understands some simple concepts. A valve component is modeled as a rigid pipe with additional properties and nice graphics. When modeling a valve of any complexity, model the functionality; i.e. rigid pipe properties, weight, type of end connections, offset weights (operator), and physical structure (additional rigid pipe or beams as needed). The following is an image of a Bell & Gossett Triple Duty Valve: Suggest modeling as a normal valve component with the correct length and weight. If concerned about the offset weight due to the body construction, insert valve's actuator to the correct location with an assumed weight, but be carefully not to double dip on weight. Another words, distribute the total valve weight between the following valve dialog fields: Valve Weight & Actuator Weight. Item #4: If I have a 90 deg angle valve or relief valve with the inlet pipe size smaller than the outlet pipe size, is it correct to model the pipe coming out of the valve as a different size than the pipe going into the valve? A warning message is given stating that the pipe diameter has changed without a reducer. Is it ok to ignore this warning in this case? Answer: Generally the vent pipe will always be bigger. There is currently 2 modeling approaches for an angle valve or relief valve: A. Model as a single valve on an incline: Please see the following AutoPIPE help section: Help Contents Contents Tab Modeling Approaches Modeling Approaches Valves Relief and Angle Valves Note: Although AutoPIPE cannot model a C.G. that is not outside the valve, AutoPIPE 9.1.1. can model a valve actuator at any orientation you wish and if that location corresponds to the location of the CG that would give a similar response. B. Modeled as two valves: model part of the valve in one direction with one pipe size and model the 2nd valve at 90 degrees with second pipe size. Note that the valves would be modeled as non-standard so that the weight is not automatically assigned. You can proportion the weight as you wish, Difference between the two model approaches: Not to be concerned, but analysis does show a very small difference in the results. This is due to the different type of construction, center of gravity; 1 valve at an angle vs 2 valves perpendicular. The following warning may appear in the model consistency check: W726-7: Pipe diameter change without a reducer at point XXX However, this is an acceptable warning to ignore because in order to model this component different pipe sizes were used without a reducer in both cases. The following enhancement has been logged, CAE-CR-11056, Add new valve type library for Press Safety / Relief Valve (PSV or PRV). Item #5: How do I analyze for a air high pressure relief valve? Answer: See AutoPIPE/Help/Workbook/Example Systems/ Water Hammer and simply change the fluid to steam or NS (non standard). Item #6: When inserting a valve with flanged end connections on both side, the wrong weight is automatically applied to the flanges. example: add a GateF Class 300 valve and tick the insert flanges option the flanges by default are the same weight as the valve. Answer: This is a known issue and has been logged under CAE-TR-10614 Using insert flange on both ends copies the weight of valve to flange and was fixed in AutoPIPE V8i 09.06.00.07 and higher. Item #7: How do I model a Fire hose valve? Answer: There are a few different varieties of Fire Hose Valves: angle type, in-line type, Wye type, etc.. When modeling a valve in AutoPIPE, the most important information is valve configuration, and end type connections. In the background, a valve is just a graphical image of rigid pipe with known weight and the correct SIF values for end connections. Therefore, model the geometric shape of the custom valve with piping components, add Rigid Pipe Properties as needed over this piping, insert added weight as needed, and insert the correct SIF values for all en connections. Note: 1. Caution, try not to double count weight from all components used in your custom valve (i.e. rigid properties, valve components, reducer components, added weight, etc.). 2. Model the Wye using the same general modeling approach as see in 3-Valve procedure above. 3. AutoPIPE's SIF calculations are all based on Piping codes. Locate a source to help calculate the correct SIF values for Fire hose connections to be used in AutoPIPE. Suggest contacting the valve manufacture for assistance. Item #8: Can you suggest a modeling approach for the following valve + actuator where the supplier only provides info on the combined unit weight and CG but no individual component (valve weight, actuator weight, etc..) details? Answer: Insert the actuator at the CG location and enter the combined valve and actuator weight on the actuator Enter valve weight = 0 See Also Bentley AutoPIPE External Links Bentley Technical Support KnowledgeBase Bentley LEARN Server Comments or Corrections? Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to the "Comments" area below. THANK YOU! If I add a valve e/g/GateF Class 300 and tick the insert flanges option the flanges by default are the same weight as the flange, hence not the correct flange. I stopped using this option because of this and instead I would just add the valve, then I would highlight thevalve and click insert flange, click insert mating flange and everything looks fins but when I checked things later I found that two flanges has been inserted at each end (4 flanges in total for one valve). Have newer versions fixed this?
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