cold embrittlement protection

[medbekkaye]

hi all,
new in the business, and i m asked to design a cold embrittlement protection for carbon steel piping of a custumer downstream a LIN vaporisation facility .the custumer does not allow a GAN supply cut for his process (inerting and blanketting).Any suggestions ? All will be welcome

 

[iainuts]

There are 2 basic ways of doing this.
1. The most obvious is to put a thermocouple or other measuring device in the line and tie it into a valve that closes when a low temperature has been reached. This works fine if you have power close by and a control panel to operate it. But it's a bit overkill.
2. The all mechanical method uses a valve that is held open by gas pressure. The gas pressure is connected to a bulb through a short hose that's immersed in the flow stream. When the temperature drops, the gas in the bulb condenses and the valve loses the pressure and closes. Kaye & MacDonald makes the valve and the entire assembly can be purchased from ACME Cryogenics.

http://www.acmecryo.com/index.cfm/f...oductID/14.cfm?CFID=30177903&CFTOKEN=82912996

I'm sure there are other suppliers of such valves and other manufacturers that will sell you a manifold with one installed but I don't know who else does this.