Avoid indicating "NACE requirements" as that will be instant $$$ on the price even though, in practice, "NACE requirements" will simply be composition, heat treatment condition, and hardness control. Best to just specify those individually rather than use a blanket term. It will be pretty much...
There is an interesting striation at the two o’clock surface that should be investigated further. Depending on the fracture toughness (note: fracture toughness, not Charpy energy) it could be that a short fatigue crack created the conditions for a brittle fracture across the bulk of the cross...
N = Normalised; Q = Quenched & tempered. That gives you a couple of terms to chat to Copilot with.
Q will have an extra heat treatment step which will occupy purchaser inspection at the plate mill should such inspection actually be deployed. In general terms, Q may have better sour service...
1. Has the integrity assessment fully confirmed that a repair intervention is absolutely required?
2. Transported fluid?
3. Pipe diameter and wall thickness?
4. Steel specification and grade?
5. Corrosion is internal, external, both...
ASME IX doesn’t deal with corrosion testing, so you are at the whim of the customer; try asking them what they specifically want. They might be happy with a satisfactory prolongation of the existing qualification and just the additional corrosion test. Of course, we could debate whether the...
If it was insulated with the normal materials, then the corrosion is more likely to be classed as corrosion under insulation CUI. Next time ensure a top quality, qualified tank lining coating, or dedicated anti-CUI coating, and a top quality insulation job...
“Inherently NACE compliant” - apart from the hardness restriction, and the limits on temperature, H2S, and chloride concentration. Maybe time to get hold of a version of the standard less than 20 years old.
The quoted clause is related to range of validity (essential variables) not consumable selection. The impact test temperature is normally taken as that defined for deposited weld metal in the “application standard”. For EN 13445, you would have to look at the requirements for impact testing of...
The weld for the pad attachment will also be prone to cracking. The cracking is from the outside inwards. If the depth of cracking has been fully characterised, and is believed to be shallow (don’t ask how shallow - what depth of cracking deemed salvageable is another risk factor...
@pipewelder1999 - there’s a lot more becoming available on open access like the paper I posted. The whole journal is open access which is the best thing because it annoys me greatly when journals that I pay good money to subscribe to then post up some of the content for free.
It depends on a number of factors, not least the risk tolerance of the end user. 90% H2S at 45 bar could give rise to a major consequence. If the end user is ok with all the aspects associated with the risk management, go with carbon steel. If they cost the risk management, they might find...
