Depends on your definition of high pressure. I do not agree.
Review a copy of the ASTM A-333 Gr 6 specification. Compare the allowable stresses in ASME II part D across the temperature spectrum with other common carbon steel piping grades like ASTM A-106-B. I've seen projects use ASTM A-333...
It is common to machine, WOL, re-machine. You need to have the proper hold points and NDE, approved weld procedures, etc.
10.1.2.3.5 "Corrosion-resistant ring grooves" of API 6A references your rough machining detail but adds that "Other weld preparations may be employed if the strength of the...
Growth occurs at the immediate surface; it is volumetric change due to the diffusion.
Amount of growth will depend on:
• Steel chemistry
• Gas dissociation or gas ratios
• Process temperature selection
• Time at process temperature
All of the previous affect the thickness of your compound...
Can any one offer up useful resources on molten salt corrosion within delayed coking units? Process side, not fire side. I have some failure analyses, internal company documents, and G.Y. Lai's book on high temperature corrosion.
Could you provide some additional information regarding the water? A good start would be water type. (River water, cooling water, steam condensate, sour water etc.) Type will dictate further questions but try and provide background information regarding the variables that affect corrosion in...
I second what NBrink has put forward. I don't read it as planning to engineer higher hardness in some of the welds, so much as identifying where the need for hardness control lies. You're building a tank, which is generally large. Any decision that you make regarding welding is compounded...
@NBrink, we got a sample from a low point and performed a water extraction and we got corrosion scale after a portion of the pipe was cut for metallurgical analysis. Both confirmed the presence of MEA and chlorides in great quantities. We should be getting the full metallurgical report soon...
Carbon steel. All the literature I've found on molten salts is very high temperature, but this is the type of information I'm looking for. Any literature or further information on molten salts at intermediate temperatures would be helpful. I'm not able to turf anything up.
We recently came...
We recently experienced through wall failure due to what appears to be under deposit corrosion in the light coker gas oil fraction. The draw temperature on this cut is right at 400F so I would consider run conditions to be too cool for high temperature corrosion mechanisms (sulfidation...
Sjones, I had worked through the 581 assessment but some of the literature I was reading gave me pause. It may be that simple. I will take a look at the NACE paper.
EdStainless, The caustic is used in petroleum refinery applications to remove sulfur species like H2S, mercaptans, disulfides...
I have some atmospheric storage tanks constructed of solid 316L stainless steel, that contain spent caustic produced as a by-product of refinery processes. They operate at ambient temperatures, 100F is the hottest temperature seen by temperature indicators. pH is in the range of 13-13.5...
Recrystallization is driven by the stored energy of deformation. As the other guys have said, a certain minimum amount of cold work is necessary for REX, this is known as critical deformation. The greater the amount of prior deformation, the lower the temperature for the start of...
Use a copy of the ASTM specifications to compare chemical compositions and mechanical properties. Can't speak to suitability without more data on these systems.
Understood. I can see how the risk for SCC would be higher given higher hardness. Say, however, the low alloy steel has been treated to meet the hardness requirements for steel in wet H2S service. I'm still interested in the aspects of wet H2S damage (Blistering, HIC) that are not primarily...
I've been unable to find material discussing the performance of low-alloy steels in wet H2S service with respect to blistering, HIC/SOHIC, etc. I understand that carbon steel is the "go-to" , but if the benefits to low-alloy steels are marginal or non-existent I'm interested in seeing...
Good Afternoon All,
I have received a sample from the boot on the cold separator upstream of a reformer. The sample includes pH, H2S content, NH3 as N, NH4HS, and chloride content. I'm looking for a resource that will give some meaning to these values. By using a combination of the NACE...
