On3LiFe,
Following my previous post, attached is another patent (1980) which involves automatic welding of a tubesheet plug that may offer some ideas should you have a number of plugs to be installed and desire automatic welding be used.
Before tubesheet plugging is considered as a "fix", the...
On3LiFe,
The attached patent (1979) may offer you some ideas as to the design of the tubesheet plug for your specific application. The hole preparation may vary (from that described in the patent) to allow for a sound weld between the plug and tubesheet. Possibly the plug could be designed to...
On3LiFe,
Re-thinking your particular case and rmw response, I feel rmw is spot on, as this issue being more a tube-to-tubesheet defect than one of tube leakage, therefore, you will want to focus on "tubesheet" hole plugging and not on tube plugging. rmw's procedure to drill out the tube end...
rmw, thank you for the caution and advice on explosive plug type. Agree it may be more than needed for this application and that the tubesheet ligament design may limit its use. The information was offered as an alternative to review and consider. A manually welded thimble type plug may be...
On3LiFe, you are very welcome. You may want to review a reference entitled "Condenser Application and Maintenance Guide" EPRI Technical Report TR-1003088 August 2001. This 340 page report offers information regarding various plug types that are being used in the condenser and heat exchanger...
I agree with EdStainless about the grooves. The use of thin wall tubes (here defined as 22 BWG and thinner wall) expanded into square edged grooves (like TEMA type) is simply a recipe for failure. The potential for failure increases with the thinner the wall, especially with titanium material...
UncleSyd and all,
See attached sketch of the shallow multi v groove design for thin wall tubes, 22 thru 27 BWG, that is best when rolling these thinner tubes. The TEMA type square edged grooves and similar may cause tube cracking or splitting of these thin walls. This design may be similar to...
UncleSyd,
I could not open the picture you attached, besides, you mention 18 BWG tubes, and I am talking about the thinner tube walls like rmw mentions, including 25 and 27 ga now being used for power plant condenser applications.
Hello unclesyd,
I am not aware of any shell and tube or steam surface condenser manufacturer who use the process you mention. Also, I have not seen this type expanding process specified or approved by the refinery, chemical or power industry customers who buy shell and tube heat exchangers and...
EuroWeld,
For your case, you might want to contact the tube supplier for their recommendations on tube expanding. If you take a look at Valtimet Technical Standards (see link) under the Tube To Tubesheet Attachment section, it recommends for mechanical expansion a tube wall reduction range of...
EdStainless,
I agree that cracking is not a concern for such thick tubes (2.11 mm, 0.083", 14 BWG) for the air cooler case described in this thread. When you had mentioned that you had seen the use of 6 shallow grooves it raised my question of groove design regarding the thinner wall tubes...
rmw and EdStainless,
I agree with your response. Do you know of any publications that discuss the potential for cracking of thin wall tubing when expanding into tubesheets with square edged grooves? To me, it seems more like "good engineering practice" and just plain common sense to avoid this...
