Ductile-Brittle transition temperature 1

[MadDog88]

Hello,

I want to carry out a pipe freeze with liquid nitrogen on a 350mm carbon steel pipe (containing cooling water) to replace a passing isolation valve. I think that it should be OK but I want to check the ductile-brittle transition temp of ASTM A53 grade B pipe but I cannot find it anywhere.

I would appreciate any help or any leads on where I can find this information.

Thanks for your help.

 

[stanweld]

A-53 B is not a low tempertaure carbon steel. Transition temperatures can be greater than 100 F.

 

[Metalguy]

If you can supply a good chemistry of the heat of steel you have, it *might* be possible to predict the d/b temp, or at least get fairly close. A-53 doesn't have to be a "killed" steel, which is partly why what Stanweld wrote is correct, and I suspect you won't be lucky with it.

 

[hacksaw]

there are other means to shut-off c.w. water lines

 

[grampi1]

Its been done on cast iron before so toughness is not really the issue. Make sure the line is depressured or as low as possible, pick a point away from welds or other stress concentrators, use a professional company that has experience.

 

[unclesyd]

I have been involved with several line, A53 and A106, freezings for stoppage and had no problems with either material. The only problems with these materials are when mother nature freezes them. I would consult with a company that specializes in pipe line stopping by freezing, there are several. They will tell you real quick if it is possible. The mechanical method mentioned is with a "Stopple" plug. This type plug is applied thru a wet tapped nozzle. They have other systems, like coming thru the valve if it is a gate valve.
One thing to remember is that to successfully freeze a line there has to be essentially no flow at the point of interest.

Check out this web site for companies that specialize in line plugging.

http://www.pipe-ez.com/pipe/0003421_0030546_1.html