I have a steam sparger which is a 21"-long 3"-dia Sch80 carbon steel pipe (with 4 full-length triangular gussets every 90 degrees) that has corrosion, erosion, and subsequent cracking. The top half of the pipe has sparge holes--a set of 8 holes between each pair of gussets. Each set has 2 rows of 4 holes, staggered vertically. The holes have grown larger in size--conically toward the outside diameter. In addition, the holes tend to aim out toward the gusset welds and as such, severe pitting is observed at each gusset weld as well. This appears to be the result of cavitation, erosion corrosion, severe pitting, and/or similar as steam exits the holes. Lastly, there are several large cracks throughout the sparger, some connecting two or more of the corroded/eroded sparge holes. The rest of the sparger is generally corroded, but nothing significant compared to this other damage. The original specification for this was Sandvik 2205. But the history is that this material failed as well. Then stainless steel was tried, but this failed even quicker. Then carbon steel was tried and appears to have remained the material of choice (whether or not is is actually better/best is up for debate). We are looking for a solution to this issue. There are three of these spargers, one for each of three production units. Repairing/replacing them requires a shutdown of the unit plus time/resources to fabricate a new sparger. Does our assessment of the damage sound right? Are there other materials out there that might be better choices? Is there a different solution (e.g., special impact resistant coating)? Thanks in advance for your help.

I agree with the comments of Mr. Hendrix....This matter is complex and deserves the review of an expert However, based on my somewhat limited experience with spargers, the erosive/corrosive problem is rarely the fault of the steam. I am assuming you are using saturated steam at some reasonable low pressure ( %7E25 TO 300 PSIG).The use of schedule 80 carbon steel piping simply buys you time, in this type of application. Does your liquid contain high chlorides ???!! I believe that your corrosion/erosion is occuring during the time that the sparger is not operating. The sparge holes are conical because the steam has produced a "fresh surface" for the process liquid to attack. If this type of low-pressure syeam sparger were heating a non-corrosive liquid, (say....heating oil) the sparger would last virtually forever. Have you considered going to the hastelloy series of materials ? ( the quintessential "bad-boy" of corrosion applications....C276 ?) My opinions only.... MJC

I agree with Mr. Parry.... The use of steam injection devices that are specifically designed for the service expected is usually the best choice. One company that produces these devices is the "Pick Heater" company (www.pickheater.com ) They have always been very helpful to me.... This paper on jacket heating may also be of help... http://www.pickheaters.com/downloads/hot_water_v_steam.pdf My opinion only.... MJC