WellFreq Engine verification · PTC 19.3 TW-2016 (R2025) Section 8

Section 8 of the Code publishes two complete worked examples with every intermediate result. They are the only independent reference available to verify an implementation. This page runs the engine against both examples on every page load, on the version actually in service.

The reference values are not reproduced here: restating them would fall under ASME copyright. Only the computed value and the relative deviation are shown, which is enough to establish conformity without substituting for purchase of the Code.

Example 8-1 — Tapered weld-in thermowell, steam header passed

Superheated steam at 232 °C and 16.2 bar g, 89.9 m/s. Tapered shank A 38.1 / B 25.4 mm, L 103.1 mm, A105 carbon steel welded into the pipe. Full calculation chain verified end to end.

QuantityClauseValue UnitDeviation
Reynolds numbereq. (6-4-3) 1.0676e+06— 0.0345 % OK
Strouhal numbereq. (6-4-2) 0.22— 0.0000 % OK
Shedding frequency fseq. (6-4-1) 778.8Hz 0.0000 % OK
Approximate frequency faeq. (6-5-1) 2 095.1Hz 0.0071 % OK
Frequency factor Hfeq. (6-5-2) 1.3519— 0.0104 % OK
Added fluid mass Ha,feq. (6-5-4) 0.99949— 0.0008 % OK
Added sensor mass Ha,seq. (6-5-5) 0.99221— 0.0014 % OK
Natural frequency fneq. (6-5-6) 2 808.9Hz 0.0048 % OK
Support compliance Hceq. (6-6-5) 0.77463— 0.0039 % OK
Installed frequency fnᶜeq. (6-6-1) 2 175.8Hz 0.0077 % OK
Scruton numbereq. (6-8-1) 4.5252— 0.0034 % OK
In-line resonance velocity V_IReq. (6-8-5) 125.6m/s 0.0217 % OK
Cyclic stress at V_IReq. (6-10-6) 183.14MPa 0.0102 % OK
Geometric parameter Geq. (6-10-7) 29.046— 0.0135 % OK
Steady drag stress S_Deq. (6-10-4) 1.314MPa 0.0141 % OK
Tangential stress S_teq. (6-11-2) 1.7206MPa 0.0167 % OK
Axial stress S_aeq. (6-11-3) 1.6705MPa 0.0086 % OK
von Mises stresseq. (6-12-2) 1.3168MPa 0.0053 % OK
Lift amplification F_Meq. (6-9-1) 1.1469— 0.0052 % OK
In-line amplification F′_Meq. (6-9-2) 2.0511— 0.0429 % OK
Cyclic stress S_o,maxeq. (6-12-3) 2.4058MPa 0.0075 % OK
Shank pressure rating P_ceq. (6-13-1) 64.736MPa 0.0024 % OK
Tip pressure rating P_teq. (6-13-2) 549.05MPa 0.0033 % OK

Example 8-2 — Threaded step-shank thermowell, hot water passed

Water at 85 °C and 4 bar g, 10 m/s. Step shank A 22.2 / B 12.7 mm, L 190 mm, Ls 63.5 mm, A182 F316 stainless, threaded. Checked at both evaluation points. The frequency is computed from eq. (6-5-3); no injected frequency is used.

QuantityClauseValue UnitDeviation
Reynolds numbereq. (6-4-3) 3.6904e+05— 0.0106 % OK
Variable Strouhal numbereq. (6-4-2) 0.204— 0.0008 % OK
Shedding frequency fseq. (6-4-1) 160.63Hz 0.0194 % OK
Approximate frequency faeq. (6-5-1) 438.55Hz 0.0111 % OK
Frequency factor Hfeq. (6-5-3) 1.5031— 0.0048 % OK
Installed frequency fnceq. (6-6-1) 545.07Hz 0.0132 % OK
Added fluid mass Ha,feq. (6-5-4) 0.93945— 0.0053 % OK
Added sensor mass Ha,seq. (6-5-5) 0.98364— 0.0039 % OK
Threaded compliance Hceq. (6-7-1) 0.89484— 0.0047 % OK
Scruton numbereq. (6-8-1) 0.029744— 0.0148 % OK
In-line resonance velocity V_IReq. (6-8-3) 16.015m/s 0.0311 % OK
Lift amplification F_Meq. (6-9-1) 1.0951— 0.0097 % OK
In-line amplification F′_Meq. (6-9-2) 1.5323— 0.0196 % OK
G at support planeeq. (6-10-9) 286.42— 0.0055 % OK
G at reduced shank baseeq. (6-10-10) 137.34— 0.0302 % OK
Kt at support planepara. 6-12.3 (b) 2.3— 0.0000 % OK
Kt at reduced shank baseeq. (6-12-4) 1.231— 0.0025 % OK
von Mises at support planeeq. (6-12-2) 19.424MPa 0.0190 % OK
von Mises at reduced shankeq. (6-12-2) 9.3175MPa 0.0052 % OK
S_o,max at support planeeq. (6-12-3) 35.285MPa 0.0130 % OK
S_o,max at reduced shankeq. (6-12-3) 9.0557MPa 0.0039 % OK
Fatigue limit F_T·F_E·Sfeq. (6-12-5) 36.437MPa 0.0084 % OK
Shank pressure rating P_ceq. (6-13-1) 35.197MPa 0.0085 % OK
Tip pressure rating P_teq. (6-13-2) 496.38MPa 0.0048 % OK