Skip to main content

Re: [MW:27756] Helium leak test in lieu of PT test for tube-to-tubesheet joints for ACHEs?

Helium leak test is more effective than PT test. It will detect minute leaks. Its sensitivity also high. In my opinion it can be accepted.Before that you need to accept their procedure and leak rate.

Venkatramulu

On Sat, Apr 28, 2018 at 4:32 PM, Makrand Sakpal <makrands9@gmail.com> wrote:

Dears, 


For tube-to-tubesheet joints in air cooled heat exchangers, can helium leak test be a substitute for PT test? One of our vendor have proposed helium leak test in lieu of PT test for tube-to-tubesheet joints.


Vendor have provided following justification,

We have offered a helium leak test after welding the tubes, in lieu of the requested liquid dye penetrant testing of the T/TS welds. We have found that the application process of spraying the liquid penetrant and developer through a plug hole using an aerosol can is ineffective as it is difficult to control the amount of chemicals being applied. we have even experienced on some jobs where excessive penetrant of developer solidifies giving false negative/positive results causing unnecessary rework or obscuring potential indications (leaks). if PT testing is desired over the helium leak testing, we can perform the testing at no charge, but will not guarantee or provide a report stating the results were acceptable. 

--
https://materials-welding.blogspot.com/
https://www.linkedin.com/groups/122787
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
Visit this group at https://groups.google.com/group/materials-welding.
For more options, visit https://groups.google.com/d/optout.

--
https://materials-welding.blogspot.com/
https://www.linkedin.com/groups/122787
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
Visit this group at https://groups.google.com/group/materials-welding.
For more options, visit https://groups.google.com/d/optout.

Comments

Popular posts from this blog

Materails FAQs

Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? (asked by: boris.vielhaber@vait.com) A: DIN Nr. = 2393 T.2, 2394 T.2, EN 10025 W. Nr. DIN 17007 = 1.0038 Design DIN 17006 = RSt 37-2, S235JRG2 (Fe 360 B) Q: What is St DIN 2391 BK material? (asked by: dmcandrews@automaticstamp.com) A: Precision steel tubes, cold-finished/hard. Q: What is C.D.W. Boiler Tube? (asked by: montydude123@yahoo.com) A: Cold Drawn Welded Boiler Tube. Q: WHAT IS W.Nr. 1.4301? PLS TELL US IN EASY LANGUAGUE (asked...

Heat tint (temper) colours on stainless steel surfaces heated in air // Heat tint

Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change.   Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...

Re: [MW:10788] ON PLOT PIPING & OFF PLOT PIPING

Piping systems involved for the flow lines and gathering lines from the well head isolation valve to the production facility or processing plant isolation valve are determined as OFF PLOT. ON PLOT defines piping system in the processing plant and production platform. ANSI/ASME B31.4 applies for off plot piping system. B31.4 allows the use of either API 1104 or ASME section IX (as appropriate). However, occasionally, a very small system such as piping within 500 feet of a processing plant (some client also said 400 feet) may be declared B31.3 rather than B31.4. When B31.3 is invoked, only ASME Section IX is used. before you decide which code to use for welding procedure and/or welder qualification for pipe welding, you have to know the design and construction code applicable to the system. Please read far enough into scope and diagram illustrating the application of either B31.3 and B31.4 hope this helps rgds 2011/4/21 pradip kumar sil < pradipsil@gmail.com > Dear all, ...