Wake Frequency Analysis

DISCLAIMER:

Daily Thermetrics Corporation has implemented this online wake frequency tool with the intent to demonstrate the compatibility of the thermowell with those operating conditions specified by the designer in conformance with the ASME PTC 19.3 TW-2016 Standard, subject to the requirements detailed in subsection 9-2.

Specification of a thermowell, including details of its intended installation and all intended operating conditions, is the responsibility of the designer of the system that incorporates the thermowell. The designer of that system is also responsible for ensuring the thermowell is compatible with the process fluid and with the design of the thermowell installation in the system.

Responsibility for validation rests solely with the user while using this web tool. Daily Thermetrics will not be liable for any damages relating to use of the information provided by this web tool calculator. For further assistance please contact Daily Thermetrics Engineering Team at techsupport@dailyinst.com.

NOTES:

1. The Shielded Length (SL) is the projection length of the nozzle plus the wall thickness of the pipeline. If shielded length is not provided then we shall assume no shielding for calculation purposes.
2. Frequency Ratio equals wake frequency (ƒ_s) divided by natural frequency (ƒ_nc). Frequency Ratio will indicate "PASS" in the Acceptability Criteria only if the following requirements are met:
3. If cyclic stress condition is "APPLICABLE", then wake frequency (ƒ_s) must be less than 0.4 times the Natural Frequency (ƒ_nc). If cyclic stress condition is "N/A", then the wake frequency shall satisfy ƒ_s < 0.4ƒ_nc or 0.6ƒ_nc < ƒ_s < 0.8ƒ_nc.
4. If low density gas condition is "PASS", then the in-line resonance is suppressed and the wake frequency shall satisfy ƒs < 0.8ƒ_nc. Cyclic stress no longer applies.