By Eng Carlos F Molina
Tank settlement was, for a long time, elusive to me. I got by only whith was needed for the exam. If you are an API 653 inspector, there are many opportunities to do inspection or consulting jobs in small tanks. The following is an introduction to the subject of settlement.
TYPES OF TANK SETTLEMENT
Settlement in tanks can be of several types. API 653 talks about three types: uniform, planar tilt and out-of-plane settlement.
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By Eng. Carlos F Molina
The following article is about API RP 652 for the API 653 certification exam. What do you think is the difference between a lining and a coating? Between a coating and a paint?….. Before you continue reading, share your thoughts in the comment section.
As far as I know, paint is a liquid or paste that, when applied in a substrate, coats a layer over the surface, protects it and then gets to be known as a coating. Any material applied to the internal surfaces of a tank to serve as a barrier to corrosion and/or product , it is known also as a lining. Right now we are going to study linings. If you are preparing to take the API 653 certification exam, do me a favor an read the 652 RP. (more…)
By Eng. Carlos F Molina
Hi. Following two months and a half of a new job in Panama, I haven´t been so atentive to my website. I am again working for a contractor, meaning I have almost no time at all to update this site. I am usually void of energy because of all of the work that needs to be done. I hope that changes in the near future. By now, I am trying to retake writing in apiexam.com and to really commit to an schedule. Even when I didn´t write in a long time, the number of people that found value in my content grew (I have 255 suscribers now) in the past 2 and a half months.
Last time, we talked about Ultrasound according to Article 23 Ultrasonic Standards, Section SE–797, only things related to the Body Of Knowledge. This time we will review the use of ultrasound in tanks.
INTRODUCTION
Ultrasonic testing, I think, is going to replace RT as a mean of inspecting welded joints in tanks, because of its many advantages, like reducing hazards and downtime associated with radiography.
By Carlos F Molina
This is my last article about radiology in tanks for readers who are studying for the API 653 exam. We will see
- Radiographic Technique
- Placement of IQIs
- Radiographic density
By Carlos Molina
Pitting is almost a common denominator of all types of localized corrosion. In fact, pitting in tanks can be a consequence of CUI (Corosion under Insulation), MIC (Microbiologically induced corrosion), Soil corrosion, Sour water corrosion, etc, all damage mechanisms mentioned in the BOK for the API 653 exam.
Having this in mind, how can we evaluate shell pitting in tanks? Please keep reading, as the explanation in the API 653 is very short.
By Carlos F Molina
TANK SHELL EVALUATION ACCORDING TO API 653
What we are going to do is to dissect the diagram in FIG. 4.1 of API653 until we truly understand it. and there will be no way we fail any of the questions related to this in the exam. First of all we are going to see the following diagram.
Look at the vertical sections drawn in the picture. Remember that hoop stresses (stresses that are tangential to the shell of the tank) are higher in vertical planes than in horizontal planes. (more…)