This dialog enables you to calculate whether a thermowell inserted into a pipe fit the allowable values for frequency, static stress, dynamic stress, and hydrostatic pressure. After Smart Instrumentation displays the calculation results, you can return to this dialog, enter different settings, and then recalculate thermowell values.
The calculation complies with the ASME PTC 19.3 - 2010 Standard.
If in the Temperature Calculation window, you entered values for the Maximum, Normal, and Minimal Velocity, Smart Instrumentation will display the results for each velocity definition after recalculating each velocity option.
Velocity
Select Minimum, Normal, or Maximum fluid flow velocity.
Types
Select the details for your thermowell type.
Thermowell type
Select one of the following types based on the shape of your thermowell:
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Tapered
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Straight
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Stepped
Thermowell connection type
Select one of the following:
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Threaded — Select this if your thermowell is inserted in the line by screwing it in.
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Other — Select this if the connection type is anything other than threaded (for example welded).
Other connection type
If you selected Other in Thermowell connection type, enter the type of connection.
Thermowell parameters
Root diameter of thermowell (A )
Outside diameter of thermowell at support plane or root, based on which point is closest to the thermowell tip.
Diameter at tip (B)
Smart Instrumentation enters this value automatically if the sensing element nominal size was entered in the Thermowell Calculation (1998 Standard) for thermowell length.
Fillet radius at root (b)
Fillet radius at the root of the thermowell shank. Select the Default button for the default value for stainless steel.
Fillet radius at base for stepped thermowell (bs)
Fillet radius at the base of the reduced-diameter length of a step-shank thermowell.Select the Default button for the default value for stainless steel.
Bore diameter of thermowell (d)
Bore diameter of the thermowell.
Unsupported length of thermowell (L)
Unsupported length of the thermowell, measured from the tip to the support plane.
Length of reduced diameter shank (Ls)
Length of reduced-diameter shank for a step-shank thermowell.
Minimum tip thickness of thermowell (t)
Minimum tip thickness of the thermowell.
Density of well material at ambient temp (ROm)
Average density of thermowell material. Select the Default button for the default value for stainless steel.
Module of elasticity at operating temperature (E)
Modulus of elasticity at service temperature. Select the Default button for the default value for stainless steel.
Reference value for module of elasticity (Eref)
Reference value for modulus of elasticity of the thermowell material at ambient temperature. Select the Default button for the default value for stainless steel.
Maximum allowable working stress (S)
Maximum allowable working stress of the thermowell material. Select the Default button for the default value for stainless steel.
Fatigue endurance limit (Sf)
Fatigue endurance limit in the high-cycle limit. Select the Default button for the default value for stainless steel.
Density of thermowell sensor at ambient temp (ROs)
Average density of thermowell sensor. Select the Default button for the default value for stainless steel.
Damping factor (Dz)
Intrinsic damping factor of the thermowell. Select the Default button for the default value for stainless steel.
Environmental factor (Fe)
Environmental factor allowing designers to adjust fatigue limits for environmental effects such as corrosive service. Select the Default button for the default value for stainless steel.
Mounting factor (Hc)
Frequency factor to account for support for foundation compliance. You can select Calculate Hc to calculate the value for Mounting factor based on the other data that you entered or you can enter a value manually.
Results
After you enter all of the necessary data, when you select Calculate, the results are displayed here.
OK
Accept your changes and close this dialog (displayed for batch calculation).
Close
For standard calculation, close this dialog. For batch calculation, close this dialog and discard your changes.
Calculate
Calculate according to the current settings and display the results in the Results section of the dialog.