Thanks very much for your comments. I still would like to have some technical reasoning for using FITTING UNION . Also, what should be the leak testing pressure and fluid to determine effectively a threaded joints sealing.
In my experience and engineering common sense the best practice in gas process plants will be to use welded joint instead of threaded one. However there is still companies fabricating / constructing using threaded joint and even using FITTING UNIONS . Recently it was known of a small fire...
What are the considerations that justified the use of CATHODIC PROTECTION and /or external paint on a DUPLEX buried gas pipeline? Can I get some hint on that?... Also if this is totally necessary, what if the efficiency of the paint system needed and how much costly is it compare to a C/S pipe...
Steve:
Thanks for the web address. Craig ARTICLE looks VERY INTERESTING.. however is not electronic ... . I look and I could not find it... DO you know of any special site?
Thanks
Is there any way to manage the following conditions with C/S ? . Please advice.. If not, could C/S+clad 3.2 mm be a reasonable and realistic option. Can INCO ALLOY SUCH AS GRADE 625 be a good option?. Is there any manufacturer that can do the piping and vessels material?
Thanks in advance...
Is there any way to manage the following conditions with C/S ? . Please advice.. If not, could C/S+clad 3.2 mm be a reasonable and realistic option. Can INCO ALLOY SUCH AS GRADE 625 be a good option?. Is there any manufacturer that can do the piping and vessels material?
Thanks in advance...
Base on experience, it will be a very good practice to PWHT in a ammonia service.....after long service time SCC can developed ... it has been observed in welds w/o PWHT in a ammonia process tanks.
I believe that PWHT is a very good improvement for the weld and HAZ in reducing risk of a SCC...
TO EVERYBODY PARTICIPATING:
Thanks to everyone for your enlighten and active participation on this topic.
Repair was done with inconel 82, 3/32" rod , preheating at 300-350 F , insulating the external side of the weld and finally flame heating for 5 to 10 minutes and then covering the weld with...
We have a proposal for the contractor to have a joint of 1.25Cr-1/2 Mo, line to vessel in reformed gas with hydrogen service, that showed a defect in Rx after PWHT to be repair with Inconel 82 and avoid a new PWHT.
After removing the transverse crack the dig area is 1x3/4 " with depth of 9 mm...
We have a joint of 1.25Cr-1/2 Mo , line to vessel in hydrogen reformer service, that showed a defect in Rx after PWHT. After removing the transverse crack the digged area is 1x3/4 " with depth of 9 mm. We are planng to fill with TIG and Inconel 82 3/32" , preheating at 150 C and covering wiht...
I will be extensive:
Cracks are seen only in the weld remained in the plug . The dia 1.5-inch cylindrical plug does not shown any damage. Also, some defects were detected with PT in adjacent area of the tube sheet. In addition, the cracks w/o etching are starting and parallel to the fracture...
I am looking for reference microstructure that relates hydrogen attack or embrittlment in ER-80S B2 filler metal that was TIG weld to a fillet weld between AISI 4140 bar and 1.25Cr-.5 Mo plate . This material was HT and the final Hardness was less than 200 BH.... Now a fail sample is showing 45...
