ASME/ISO/MSS Flange - Tension
You need to complete the requested data at the top of the screen.
WARNING: Flange Yield Strength. As a precaution the Calculator requires you to confirm that the minimum yield strength of your flange is at least 248 N/mm2 or 36000 p.s.i. Note: If your flange material has a lower yield strength than these values there is a possibility that using the bolt load values from the calculator will cause permanent damage to your flange.
[Warning! Please confirm the flange material has a yield strength of at least 36000 psi or 248 N/mm˛. If the material strength is less, the flange may be damaged. Calculator also assumes no corrosion damage has taken place.]
You are then asked whether the application is weld neck to weld neck. This information is required to calculate the stressed length of bolt in the event you wish to choose to use tensioners on this flange joint. If your application is weld neck to weld neck, click the "Yes" box and continue. If it is not, you will need to click the "No" box and state the length between the flange faces in either mm or inches as selected. Use the box labelled Grip Length. For example, the length will need to be inputted if you have a spade, swivel or a blind fitted either between the weld neck flanges or in place of one of the flanges.
The program has the facility for you to choose the Tool Type and Tool Model you are using for tensioning of this particular flange. The selection options will be limited to the appropriate models for the tool range you have chosen to purchase or hire. If your tool model does not appear in the list, please contact Hydratight. Once you have made your selection, the tools key dimensions will be displayed on the drawing on the right hand side of the screen.
You may ignore Max WP and Hyd Press Area unless your Calculator has been programmed to allow you to input your own customer specific tool model. For more information please read Appendix 2.0.
Tensioning procedure: This is the number of tools you simultaneously pressurise when tensioning this particular flange joint expressed as a percentage of the total number. Your choices are: 100%, 50%, 33% and 25%.
The Calculator will calculate hydraulic tool pressures from two and usually three specified bolt loads.
No 1 is the minimum bolt stress and bolt load required to seal this flange joint for the conditions entered based on the ASME 8 code. This value was calculated from the data entered and shown on the previous screen. The calculations also give the percentage of bolt material yield as a quick visual check that the data is meaningful.
No 2 allows you to specify a bolt load or bolt stress that you require to achieve in the bolted joint. The data can be entered in either metric or imperial units but care should be taken to make sure the data is entered correctly. As an alternative you can also enter the required bolt load as a percentage of the yield strength of the chosen bolt material. The default is set to zero. If left at zero no tool pressure values will be displayed.
No 3 displays our recommendation for bolt load and stress based on Hydratight custom, practice, experience and knowledge. If no value is displayed this is because we have insufficient experience of this flange to make a recommendation. If you require further advice please contact Hydratight.
You should now click "Calculate". The Calculator will now confirm the chosen tool will fit the application, calculate hydraulic tool pressures based on the chosen tool pressures, as well as display the key inputs used in the calculation.
Inputs displays the key data used in the calculations. You should check the data is accurate and in accordance with your application. This is the key data that needs to be correct to ensure you achieve a seal without damaging the bolt or flange.
Inputs include Min Bolt Length. This is the bolt length required for your chosen flange using tensioners onshore or topside. The length displayed is based on a weld neck to weld neck connection.
Tool Fit is an aid to confirm whether the chosen tool will fit your particular application. For a standard flange, such as an ASME/ANSI, MSS, or ISO, the geometry is set by the code. The data will be imported and the key dimensions used to confirm whether the chosen tool will fit or not. Two points to be aware of:
a) You have the option to check the headroom clearance. This is optional but advisable if you have any concerns. To do this click "Is Relevant", enter the headroom value in the box below, confirm the units (mm or ins) and click "Check". The result will be displayed in the Constraint Check Box on the right hand side.
b) If, when selecting Tool Model, you had more than one tool choice, you may find for some applications only one choice will fit. To check, choose the alternative tool model, press "Calculate" again and follow the Tool Fit constraint check procedure as above.
Results. For each bolt load value a corresponding Pressure A and Pressure B will be displayed based on the tool model you have selected. A set of values will be displayed for the Minimum Bolt Load condition labelled Min. Load, as well as values for the load or bolt stress you have inputted, labelled User Spec. If Hydratight have made a recommendation there will be a third set of values labelled HS Rec.
This section summarises the information that is used for the calculation of the hydraulic bolt tensioner pressures.
It displays the load conditions in kN and lbf for the two or three loading conditions explained above.
Unless 100% tensioning has been selected the display will include Pressure A and a Pressure B for each loading condition. For 100% tensioning only a Pressure B is given.
If the Pressure B, which usually be the lower than Pressure A exceeds the safe working pressure of the chosen tool, a red coloured warning will be displayed. This indicates the tool has insufficient capacity. Please contact Hydratight.
UNDER NO CIRCUMSTANCES FOR SAFETY REASONS SHOULD THE TOOL EVER BE USED BEYOND THIS STATED PRESSURE.
The Pressure A and Pressure B should be used in conjunction with, and after having read and understood, the relevant procedure.
For each row of values further information can be obtained by clicking on View Details. For more information see section labelled VIEW DETAILS.