
Calculate mounting factor:
*L [m]

Threaded connection:

Other connection types:


Calculate Reynolds number:

Calculate Strouhal number:

Calculate natural frequency:
*L [m], B[m,] E[Pag]

Calculate average outside diameter:

Tapered thermowell:

Other thermowells:

Calculate approximate natural frequency:

Calculate correction factor Hf

Tapered and straight thermowell:

Stepped thermowell:

Calculate correction factor Haf:

Calculate correction factor Has:

Calculate natural frequency with ideal support:

Calculate natural frequency of the mounted thermowell:


Calculate Vortex shedding frequency
*B[m]

Calculate Scruton number:
*B[m]

Calculate miscellaneous parameters:
*B[m], L[m], E[Pag

Parameter Gsp

Tapered and straight thermowell:

Stepped thermowell

Parameter Grd (for stepped thermowell only):

Stress concentration factor:

Threaded connections:

Other connections:

Stress concentration factor at support plane (for stepped thermowell only):

Temperature derating factor:


Calculate Frequency Limit

Low density gases: Nsc >2.5 and Tr ,100000

General case: Other values of Nsc and Re


Compliance with the frequency limit requirement:

Initial evaluation of compliance:

The thermowell is in compliance with the frequency limit requirement if;
Go to step 10.

The thermowell is noncompliant with the frequency limit requirement if;
Go to step 10.

Evaluate compliance with cyclic stress limit for general case:

Calculate velocity for inline resonance:

Calculate cyclic drag stress at the root:

Calculate combined drag and lift stresses:

Calculate fatigue stress limit:

Compliance with cyclic stress limit:

Tapered and straight thermowell:

Not compliant with the cyclic stress limit and frequency limit if;
Go to step 10.

Complies with the cyclic stress limit if;
Set new frequency limit:
Go to step 9g


Stepped thermowell:

Not compliant with the cyclic stress limit and frequency limit if;
Go to step 10.

Case
Calculate:

Not compliant with the cyclic stress limit and frequency limit if;
Go to step 10.

Complies with the cyclic stress limit if;
Set new frequency limit:
Go to step 9g.


Reevaluate compliance with the frequency limit requirement if cyclic stress is acceptable:

The thermowell is in compliance with the frequency limit requirement if;

The thermowell is in noncompliant with the frequency limit requirement if;


Compliance with the static stress limit requirement:
*B[m], P[Pag], S[Pag]

Calculate radial, tangential, and axial stress due to external pressure:

Calculate steadystate drag stress at the root:

Calculate steadystate stress due to the drag force:

Calculate maximum stress:

Calculate lefthand side of the Von Mises criteria:

Calculate righthand side of the Von Mises criteria:
Compliance

Tapered and straight thermowell:

Not compiled with the static stress limit if;

Complies with the static limit if;


Stepped thermowell:

Not compiled with the static stress limit if;

Case
Calculate:

Not compliant with the static stress limit if;

Complies with the static stress limit if;



Compliance with the Dynamic Stress Limit requirement
Calculate parameters:

Calculate drag and lift stresses at the root:

Calculate combined drag and lift stresses:

Calculate fatigue stress limit:
Compliance

Tapered and straight thermowell

Not compliant with the dynamic stress limit if;

Complies with the dynamic stress limit if;


Stepped thermowell

Not compliant with the dynamic stress limit if;
Go to Compliance with the Hydrostatic Pressure Limit requirement section in this topic



Calculate:

Not compliant with the dynamic stress limit if;

Complies with the dynamic stress limit if;



Compliance with the Hydrostatic Pressure Limit requirement
*B[m], P[Pag], S[Pag]

Calculate pressure rating for the shank:

Calculate external pressure rating for the tip:

Calculate pressure rating of the thermowell:

Compliance

Not compliant with the hydrostatic pressure limit if;

Compliant with hydrostatic pressure limit if;