Retractable Sample Probe 1

[Taufiksaat]

Hello Members,

Could anyone share how to calculate the Wake Frequency for Retractable Sample Probe?

thank you

 

[LittleInch]

Generally just ask the vendor to do it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[SJones]

http://publishing.energyinst.org/fe...n-induced-fatigue-failure-in-process-pipework

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[XL83NL]

Though it's for thermowells, ASME PTC 19.3 TW has a method to determine wake frequencies. Thermowell shapes have some similarities with sample probes, so maybe you can have a look at that.

A quick Google search yields the following links which may be useful;
-

http://www.emersonprocessxperts.com/2013/01/online-calculation-tool-for-thermowell-installations/

-

http://www.eng-tips.com/viewthread.cfm?qid=280642

 

[hacksaw]

Dimsional specifics as well as the nominal, main pipe flow P,T, flow rate or velocity) would benefit the responses you get

With sample tubes, you have to concern yourself with a different set of criteria than used for thermowells. Same equations more of less but different priorites...

 

[Taufiksaat]

I found this:

http://docslide.us/documents/probe-calculation.html

 

[Tuckabag]

Suggest you look at EEMUA Pub. 138 and IEC/TR 61831:1999.
Both standards contain wake frequency and bending moment calculations for sample probes.
ASME PTC 19.3TW is a right pain to use for sample probes, particularly retractable ones. This is due to the additional length required to insert the retractable probe through the isolation ball valve (and even worse when it's DBBV). This is even more true for the 2010 onwards editions of the standard as the required probe diameters needed to pass the calcs render the probes basically unusable on standard sampling connections (generally 2" max flange).

However as suggested above it's best to consult your sample probe vendor as they (should) have all these calculations and can advise on the most appropriate design to suit each particular installation.