Magnetic Flux Leakage Testing of Fired Heater Tubes 1

[spayette]

Does anyone have an opinion concerning the neccesity for magnetic flux leakage testing of fired heater tubes which in all respects comply with the standard requirements of ASTM A-335 Gr P91? The tubes (pipe) are nominal 6 inch diameter, Sch. 40 and were hydrotested at the mill to 2800 psi. Tube metal temperatures are 975F and 1200F.

If anyone has experience to indicate that MFL testing is a requirement is there an acceptable alternative test that can be performed?

 

[unclesyd]

B&W has teamed with Longview inspection for the MFL inspection. But Longview in turn has started using MIB(Mutual Inductance Bridge) to access boiler tube wall condition.

We had some MFL work on some tubes in a Waste Heat Boiler and were satisfied with the results.

I’ve heard from a person at Longview that the MIB technique is very good for boiler tube assessment.

Boilers

http://www.babcock.com/pgg/tt/lit.html

MFL

http://www.lii-nde.com:8282/rockwood/

MIB

http://www.avistarinc.com/services/boiler_inspection.html

 

[stanweld]

Magnetic flux testing would be an an "add on" for new purchases. I have not seen it specified in any Engineering Specification for any new P91 pipe installed by our company-over 100,000 ft installed to date on both Power and Petrochemical projects.

As unclesyd indicates, it would more likely be specified to assess tube condition in operating systems.

 

[spayette]

Stanweld,

Thanks for your response. Are you able to indicate what company that you work for?

 

[stanweld]

spayette,

I am sorry; I am unable to state my company's name. We operate primarily in the southern half of the U.S.A.