Freeze Plug Application Experience / Technical Data

Gentlemen - I am looking for any information regarding the Freeze Plug technology. We have been contracted to oversee 3 Freeze Plug installations, 1 - 30" & 2 - 24" on an existing offshore platform. I need information in relation to past experience & any related metallurgical problems which could occur (pipe, welds, etc.). material is Carbon steel & cooling medium is liquid N2. Next week we have meetings with both the contractor & an independent specialist - any other information would be of great help.

I googled freeze plug and found this

www.pipefreezing.com/

Hope this will help. I'm actually surprised with the technology, as I would avoid Liq N2 coming in contact with CS...