Applies To Product(s): OpenPlant Modeler Version(s): 08.11.09.XXX Environment: Windows 7 64 bit Area: Component Subarea: Data Original Author: Rahul Kumar, Bentley Technical Support Group Bolt Lengths Calculation in OpenPlant Modeler has been described below with Various cases. Background Bolts: The Bolt selection mechanism does not select an individual bolt by the size (diameter) of bolt required but rather it will select the predefined “set” sized for a standard bolting of each facing, rating and size. In OpenPlant Modeler, two basic types of bolt has been classified, such as Machine Bolts and Stud Bolts which further has been categorized under BOLT/STUD BOLT class and significantly using its properties like BOLT_LEN, NUT_LENGTH, BOLT_INC, BOLT_XCESS etc. This set is read from the spec and all properties including bolt diameter and number required are read from the spec unaltered. The length of the bolts in Open Plant Modeler is typically calculated as described below. Controlling Through Variable A configuration variable (set for each workspace) will toggle if the calculated length is included in the query. This variable is OPM_QUERY_BOLTS_WITH_IGNORE_LENGTH = (0 or 1) The default value is “0” meaning all bolt spec queries will first try to find the correct value for bolt length in the BOLT_LENGTH column of the spec. If no records are found then the length is removed and the first record found is used. Setting this variable to “1” will prevent OpenPlant from querying on length. E.g. if we set the variable to ‘1’ here, it takes BOLT_LEN= 88.9 MM only. See explanations in the sample calculation provided below. Bolt Length Calculation: Length calculated by OPM is dependent on type of bolts and connection. These can be divided in to three main groups: Wafer Connection Machined Bolts Stud Bolts Lap Joint Stub End Flange Connection Machined Bolts Stud Bolts General Flange Connection Machined Bolts Stud Bolts Wafer Connection: Machine Bolt has a hexagon head and one threaded end with nut and excess. The Head is not part of the length of a Machine bolt. For these bolts we have the code logic, so a general formula for machined bolt’s length: Machine Bolt_Length = COMP_LEN + [(Gasket_Thickness) x 2] + [(Flange_Thickness) x 2] + Nut_length + BOLT_XCESS Stud Bolt has threads both ends, nuts both ends and excess both ends. So a general formula for stud bolt’s length: Stud Bolt_Length = COMP_LEN + [(Gasket_Thickness) x 2] + [(Flange_Thickness) x 2] + [(Nut_length) x 2] + [(BOLT_XCESS) x 2] COMP_LEN here is the length of wafer assembly. See image above for clarification: Lap Joint Stub End Flange Connection: Machine Bolt has a hexagon head and one threaded end with nut and excess. The Head is not part of the length of a Machine bolt. So a general formula for machined bolt’s length: Machine Bolt_Length = (Gasket_Thickness) + [(Flange_Thickness) x 2] + [(STUB_THK) x 2] + Nut_length + BOLT_XCESS Stud Bolt has threads both ends, nuts both ends and excess both ends. So a general formula for stud bolt’s length: Stud Bolt_Length = (Gasket_Thickness) + [(Flange_Thickness) x 2] + [(STUB_THK) x 2] + [(Nut_length) x 2] + [(BOLT_XCESS) x 2] General Flange Connection: Machine Bolt has a hexagon head and one threaded end with nut and excess. The Head is not part of the length of a Machine bolt. So a general formula for machined bolt’s length: Machine Bolt_Length = (Gasket_Thickness) + [(Flange_Thickness) x 2] + Nut_length + BOLT_XCESS Stud Bolt has threads both ends, nuts both ends and excess both ends. So a general formula for stud bolt’s length: Stud Bolt_Length = (Gasket_Thickness) + [(Flange_Thickness) x 2] + [(Nut_length) x 2] + [(BOLT_XCESS) x 2] Let's Take an Exercise For Each Case Mentioned Above For Wafer Type Connection: For Machine Bolt length Calculation: Pipe Size = DN 100 Spec = mA1-OPM Flange THK = 23.9 MM Gasket- 3.2 MM Nutlength/NUT_LEN = 14.3 MM COMP_LEN = 55.6 MM Bolt_EXCESS/ Bolt extension length = 7.1 MM BOLT_LEN= 76.2 MM (As you can see Bolt_D_X_L = 3“length) Using equation, Machine Bolt_Length = COMP_LEN + [(Gasket_Thickness) x 2] + [(Flange_Thickness) x 2] + Nut_length + BOLT_XCESS = 55.6+ (3.2 X2) + (23.9x2) +14.3 + 7.1 = 131.2 MM Manual calculated length = 131.2 MM, as in OpenPlant Modeler dimension. Role of BOLT_INC As described above, it should get added to BOLT_LEN 9 times to surpass the above calculated value 131.2 MM. Here it should be BOLT_LEN+ BOLT_INC = 76.2 + (6.4x9) = 133.8 MM. See Bolt Length shown below in element info, In Spec: 76.2mm For Stud Bolt length Calculation: Similar procedure like explained above for Machine bolt, will be applicable for Stud Bolt using the formula, Stud Bolt_Length = COMP_LEN + [(Gasket_Thickness) x 2] + [(Flange_Thickness) x 2] + [(Nut_length) x 2] + [(BOLT_XCESS) x 2] Using Stud bolt, calculated length in this case = 55.6 + (3.2x2) + (23.9x2) + (14.3x2) + (7.1x2) = 152.6 MM As per record shown above, the Length is 88.9 MM it again adds BOLT_INC value, i.e. 95.3+6.4 = 101.7 MM Element Info Shows: 101.7 MM, see image below: In Spec: 88.9 MM For Stud Bolt length Calculation: Similar procedure like explained above for Machine bolt, will be applicable for Stud Bolt using the formula, Stud Bolt_Length = (Gasket_Thickness) + [(Flange_Thickness) x 2] + [(Nut_length) x 2] + [(BOLT_XCESS) x 2] Using Stud bolt, calculated length in this case, = 15.9 + (28.4x2) + (19.05x2) + (9.525x2) = 129.85 MM As per record the Length is 139.7 MM which is greater than the calculated value 129.85 mm. Hence no BOLT_INC required and final length would be 139.7 MM. See image below. Using Variable: By Setting the variable OPM_QUERY_BOLTS_WITH_IGNORE_LENGTH = 1, It ignores the calculation shown above for Machine Bolts and consider the value as per record i.e. 88.9 MM as a final one. See image below for same set of bolts. Comments or Corrections? Bentley's Technical Support Group requests that you please confine any comments you have on this Wiki entry to this "Comments or Corrections?" section. THANK YOU!
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