The minimum thickness of .680 on the U1 is the minimum thickness after forming, not the minimum thickness based on design.
.680-.010-.0625 = Alarm Thickness / tmin
PD/2SE-0.2P = Pressure Design Thickness
ASME Sec. VII Div. 1 UG-32
API 571 reads:
Cracking can be effectively prevented by means of a stress-relieving heat treatment (e.g. PWHT). A heat
treatment at 1150 °F (620 °C) minimum with a minimum holding time of 1 hr is considered an effective stress
relieving heat treatment for carbon steel.
What will be the...
"how ever there may be Intergranul attack which is not visible to the eye." 100% CUI Corrosion I wouldn't be concerned.
CUI corrosion around the horizontal weld seam. You can see in the image that the corrosion is worse on the top side of the weld seam. The weld seam is acting like a...
It looks to be typical Chloride pitting caused by the breakdown of the protective oxide layer when exposed to high chloride concentrations found in seawater. Apply a good coating to mitigate.
If the results of the fitness for service require a rerate or repair the vessel should be taken out of service immediately to make the repairs or a rerate should be performed. The point of the evaluation is to determine if the vessel is fit for continued service. Failing to do so would be the...
The spacer ring will have little to no effect on the carbon steel piping. Now, if it was the other way around and the piping was stainless and the spacer was carbon steel it would be affected more.
A long screwdriver....
The corrosion products have very little strength so just scrape them off then do some UT.
This is not good advice. Do not do this unless the system is very low pressure and the process contained is not dangerous. Believe it or not, a little bit of scale can block a...
It's a simple repair. As Christine74 mentioned above an R stamp is not required unless it's needed for the owner user or your jurisdictional. If not then you can do a 510 routine repair but an API 510 has to be involved with the repair planning and the final acceptance.
At a minimum, the...
That's an interesting article. I have read theories and reports on PTFE fasteners being prone to self-loosening due to the nuts being oversized to make up the difference for the coating thickness.
At my site, we only use PTFE-coated fasteners and are a batch-production therefore the...
API 510 section 6.5.1.4 answers your question.
6.5.1.4 For pressure vessels in noncontinuous service, the interval is based on the number of years of actual
service (vessel in operation) instead of calendar years, provided that when idled, the vessel is:
a) [highlight #FCE94F]isolated from the...
I have a 10ft Diameter sloped bottom Carbon Steel API 620 storage tank that rests on an elevated concrete foundation with leak detection grooves that was constructed in 1991. Between the tank bottom and the concrete foundation is a 1/2" Asphalt Impregnated board. Over time the Asphalt board has...
9.11.1.3 "The use of welded-on patch plates that do not meet the requirements of 9.11.1.1 or 9.11.1.2 is permitted if the repair method has been reviewed and approved by an engineer experienced in storage tank design in accordance with API 650". This can be done if your thickness is less than...
You can add the 2" nozzle as long as it meets the design requirements of the applicable construction code. This will fall under a 510 repair and will not require an R-Stamp UNLESS your company or jurisdiction requires it to be. Even if an R-Stamp is not required the company doing the work must...
API 574 Table 7 shows an example of alert thicknesses for carbon and low-alloy steel pipe that could be used in conjunction with the default minimum structural thicknesses.
