hydraulic piping reapirs

Date 04-27-2002 09:36

I need to make repairs on some hydraulic piping. The welds have begun to leak, probably from poor quality but I have not seen them yet. What methods of inspection would be used to check weld quality besides visual (UT,RT...etc)? Also what is the best way to clean these areas where the weld has cracked to prevent any contamination of the new repair? These are socket type fittings on schedule 80 steel pipe. Thanks for any response.

By NDTIII

Date 04-27-2002 10:08

Your best bet is to try liquid penetrant on socket welds. UT and RT are not usually practical for socket welds. Vapor degreasing would be your best method of cleaning, however, since they cracked, you may want to cut them out and reweld them from scratch.

By Michael Sherman (***)

Date 04-27-2002 13:01

Steelman, this type of repair is usually done in an extremely dirty enviroment. I have had success using E6010 on this type of repair (it is very good in a less than perfect enviroment), pressurizing the line and checking with a product by Swagelok called Snoop. It is the "soapy bubble" method. As a thought on why this type of weld fails, among other things I have found that the fillet weld was undersized. There is alot of movement and flex on most hydraulic lines from the instant on and off of machines and motors that they operate. An undersized fillet weld will fail that much quicker. I hope this helps.

Respectfully,
Mike Sherman
Shermans Welding