Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, is a recommended practice developed and published by the American Petroleum Institute (API) that provides an in-depth look at nearly 70 different damage mechanisms that can occur to process equipment in refineries. According to the third edition of this recommended practice, its purpose is “to describe the wide variety of service-induced damage and deterioration mechanisms, including corrosion and other types of metallurgical damage, that are most likely to affect the condition of the materials of construction commonly used in refinery equipment.” However, much of the information included in this document can also be applied to petrochemical and other industrial applications, as the user deems appropriate. API RP 571 was originally published in 2003, and the third edition was released in March of 2020. This RP is intended to supplement API RP 580, API RP 581, and API RP 579, and is nearly 400 pages long.

<span>Comparing </span><span>NACE MR0175 /ISO 15156 Vs </span><span>NACE MR0103 /ISO 17495-1</span> <div> <span><br></span> </div> <div> <span> <div> <span>Always in pipeline systems we met the material with NACE MR0175/ISO 15156 pipe or fittings, so do you really know what is the major differences between NACE carbon pipe and normal carbon steel pipe? And how is the cost for nace material?</span> </div> <div> <span><br></span> </div> <div> <span>So today we are going to introduce NACE MR0172 / ISO 15156 from different aspects as below:</span> </div> <div> <span><br></span> </div> <div> <span>Definitions and means</span> </div> <div> <span>Standard Scope</span> </div> <div> <span>Related equipment and products</span> </div> <div> <span>Material Cost</span> </div> <div> <span>Chemical Compositions</span> </div> <div> <span>Mechanical Strength</span> </div> <div> <span>Applications</span> </div> <div> <span>Work Conditions</span> </div> <div> <span>Notifications before Purchasing Nace Pipe and Fittings</span> </div></span> </div>

Fatigue is a process in which damage accumulates due to the repetitive application of loads that may fall below the yield point. Fatigue is the initiation and propagation of microscopic cracks into macro cracks through repeated application of stresses. All structural steel materials contain metallurgical or fabrication-related discontinuities, and most also include severe stress concentrators. The fatigue begins as an internal or surface flaw where the stresses are concentrated and consist initially of shear flow along slip planes. Over a number of cycles, this slip generates intrusions and extrusions that begin to resemble a crack. A true crack, running inward from an intrusion region, may propagate initially along one of the original slip planes but eventually turns to propagate transversely to the principal normal stress until observing a sudden fracture of the remaining cross-section. The phenomenon may be problematic because a single application of the load would not produce any sign of defect, and a conventional stress analysis may lead to an assumption of safety that does not exist. The history of fatigue covering a time span from 1837 to 1994 was reviewed in an extensive paper by Walter Schütz [1]. Historical milestone papers were collected by Hanewinkel and Zenner [2] and Sanfor [3]. John Mann [4] compiled 21075 literature sources on fatigue problems covering the period from 1838 to 1969 in four books. Since that time the number of publications on fatigue has still considerably increased and it may be estimated to be around 100,000 in the year 2000. Fortunately, consulting the literature on specific topics can now be done with computerized literature retrieval systems.

<div> Liquefied natural gas (LNG) is a source of clean energy with stable long-term supplies that was first </div> <div> introduced into Japan in 1969. Since that time, sixty-six in-ground tanks for the storage of LNG, with a total </div> <div> capacity of 5,540,000 kiloliters, have been constructed in the country. Rapid developments in the technology </div> <div> used to construct these in-ground tanks, including the introduction of the super-deep slurry wall method and </div> <div> large-scale vertical NATM, have led to ever-increasing storage capacity — rising from 10,000 kiloliters in </div> <div> the early days to 200,000 kiloliters today. Completely buried tanks with concrete dome roofs have been </div> <div> constructed, and today’s technology is such that tanks with rigid side wall to bottom connections are being </div> <div> constructed in large numbers for cost reduction while enhancing reliability and safety. This paper describes </div> <div> trends in LNG tank technology and the latest technological developments, as achieved by the author in his </div> <div> work at Tokyo Gas Co., Ltd. </div> <div> <br> </div> <div> Keywords: LNG in-ground tank; slurry wall; reinforced concrete dome roof; prestressed concrete; </div> <div> non-linear analysis; self-compacting concrete; rigid connection between side wall and bottom slab </div> <div> <br> </div>

Temper Bead Welding (TBW) Temper Bead Welding (TBW) was adopted into the 2004 Edition of the ASME Boiler and Pressure Vessel Code, Section IX; the adoption of TBW has permitted welders to strategically exploit the effects of welding. Of particular note, is the ability to utilize TBW to create a weldment with improved strength and low temperature impact properties without the application of post weld heat treatment (PWHT). However, to reliably obtain these benefits requires development of a robust welding procedure, performance qualification and parameter controls during production welding. The origins of the process can be traced back to the half-bead repair approach using SMAW electrodes

Joint efficiency is a factor required in all head and shell calculations that accounts for how closely a finished weld joint approximates the quality of the seamless parent material. Without further inspection it is assumed the welded joint is weaker than the material around it due to potential defects such as porosity, slag inclusions, and others. Shell thickness and therefore weld quantity is increased to account for this reduction in strength. Code welders following a qualified weld procedure are tested to weld a finished joint that maintains 100% of the parent material strength, but without further testing the allowed strength of a production joint is reduced to 70%. For some design conditions, such as lethal service, the Code requires the designer to specify full radiography. However, when not required, the designer can specify optional radiographic examination to increase joint efficiency and reduce the required thickness of shells and heads. The designer weighs the material and welding costs against inspection costs to determine which course is best suited for the application.  The figures below show the ASME VIII-1 joint efficiency values based on Type 1 joints (butt joints fully welded from both sides or equivalent) and degree of radiographic examination. The information is generated using the radiography logic diagrams and samples from Part 7 of PTB-4-2013 ASME Section VIII – Division 1 Example Problem Manual – the PTB-4 ‘E7.1’ through ‘E7.4’ example numbers are indicated where applicable. Radiography test is a nondestructive testing method of inspecting some hidden cracks in the material by using radio magnetic radiation to penetrate through the materials. The purpose is to ensure the structural integrity of the weld joint. As per ASME, there are four types of Radiography test (RT), i.e. RT1, RT2, RT3 and RT4. Joint efficiency is the number used to define welded joint strength which basically depends on the RT type. This Joint efficiency plays a vital role in determining the thickness of the pressure vessel components in Mechanical calculation. For RT1 and RT2 joint efficiency is 1.0, for RT3 efficiency is 0.85 and for RT4 efficiency is 0.70. The Weld Joint Category is how each weld on a Pressure Vessel Engineering is classified to a Joint category, based on the criticality. As per ASME there are four types of weld joint categories, Category A, Category B, Category C, and Category D. Now we can see how these three are interlinked as per ASME Sec VIII Div.1 As per ASME Sec VIII Div.1 the RT type 1 or 2 or 3 or 4 will be selected based on the type of weld joint category A or B or C or D. In turn the type of RT 1 or 2 or 3 or 4 will decide the Joint efficiency value 1.0 or 0.85 or 0.7. So this is how the Radiography test, Joint efficiency and Weld Joint category are interlinked as per ASME Sec VIII Div.1. To give an example, we have detailed the RT type with Joint efficiency based on weld category. Category A and D butt welds shall be fully radiography (RT1) hence the Joint efficiency is 1.0. Category B and C butt welds shall be spot radiography (RT3) hence the joint efficiency is 0.85. This is because longitudinal joints are more critical than circumferential joints. In general, heads connecting with shell will fall on Category B (RT-3 Spot Radiography), however in case of hemispherical head, the head with shell joint will fall on Category A (RT-2 full radiography), because this joint is more critical or it will be under double stress.

<div> Types of Industrial Pumps Used in the Oil and Gas Industry </div> <div> Various types of industrial pumps are utilized for fluid transfer in the oil and gas industry. Pumps used in O&G can be classified based on their design and construction and generally fall into 6 major categories: </div> <div> <span>Centrifugal pumps</span> </div> <div> Reciprocating plunger pumps </div> <div> Progressive Cavity pumps </div> <div> Gear Pumps </div> <div> Diaphragm pumps </div> <div> Metering pumps </div> <div> <span>1. Centrifugal Pumps</span> </div> <div> Centrifugal pumps are the most common types of pumps used in the oil and gas industry. Centrifugal pumps use centrifugal force through the rotation of the pump impeller to draw fluid into the intake of the pump and force it through the discharge section via centrifugal force. The flow through the pump is controlled by discharge flow control valves. </div> <div> <span>Single stage centrifugal pumps are primarily used for transferring low-viscosity fluids that require high flow rates. They are typically used as part of a larger pump network comprising other centrifugal pumps like horizontal multistage pump units for crude oil shipping or water injection pumps used in secondary oil and gas recovery.</span> </div>

Radiography is carried out based on the geometrical shape of the material and the required details of the image. The best possible configuration is chosen and the film placement and location of radiation source is determined. In this respect the configuration of cylindrical objects like pipeline and offshore structural members are more critical.

Measuring the flow of liquids is a critical need in many industrial applications. In some operations, the ability to conduct accurate flow measurements is so important that it can make the difference between making a profit or taking a loss. In other cases, inaccurate flow measurements – or failure to take measurements – can cause serious (or even disastrous) results. With most liquid flow measurement instruments, the flow rate is determined inferentially by measuring the liquid’s velocity or the change in kinetic energy. Velocity depends on the pressure differential that is forcing the liquid through a pipe or conduit. Because the pipe’s cross-sectional area is known and remains constant, the average velocity is an indication of the flow rate. The basic relationship for determining the liquid’s flow rate in such cases is: Q = V x A Where Q = Liquid flow through the pipe V = Average velocity of the flow A = Cross-sectional area of the pipe Other factors that affect liquid flow rate include the liquid’s viscosity and density, as well as the friction of the liquid in contact with the pipe. What is a Flow Meter? A flow meter (or a flow sensor) is type of flow instrument that is used to indicate the amount of liquid, gas, or vapor moving through a pipe or conduit by measuring linear, non-linear, mass, or volumetric flow rates. Since flow control is often essential, measuring the flow of liquids and gasses is a critical need for many industrial applications – and there are many different types of flow meters that can be utilized depending on the nature of the application. When choosing a flow meter, one should consider such intangible factors as familiarity of plant personnel, their experience with calibration and maintenance, spare parts availability, and meant time between failure history, etc., at the particular plant site. It is also recommended that the cost of the installation be computed only after taking these steps. One of the most common flow measurement mistakes is the reversal of this sequence: instead of selecting a sensor which will perform properly, an attempt is made to justify the use of a device because it is less expensive. Those “inexpensive” purchases can be the costliest installations.