Shahab Zangeneh, PhD’s Post

When designing pressure vessels based on ASME BPVC. Sec.VIII Div.2 for protection against plastic collapse, there are three methods available, namely: 1. Elastic Stress Analysis Method 2. Limit Load Method 3. Elastic-Plastic Stress Analysis Method In the first method you deal with allowable stresses. In second and third, you deal with Load & Resistance Factors Design (LRFD). The following paper is an old antique explaining how LRFD method is born and formulated. 🔥 Join me on telegram: Incinerator group: https://lnkd.in/ex26Njt5 Fired heater group: http://t.me/FiredHeater #MechanicalEngineer #ProcessDesign #PressureVessel #BPVC_VIII_2 #ASME #LRFD #Stress

Field vane test (FVT) is governed by EN ISO 22476 Part 9 for United Kingdom and European region, and ASTM D2573 for the United States. This test aims to determine the undrained shear strength of fine-grained soils, notably the clay. The test instrument consists of four stainless steel vane blades, and all of them are connected to a vane shaft. The thickness of blades are kept smaller than 3mm to minimize the disturbance of soil during the insertion prior to test. The vane blades can be either rectangular in shape, or tapered at the ends. After the device is penetrated into the soil underneath a borehole, rotation rate of 6 to 12 degree per minute is applied to the vane. Maximum torque required to rotate the vane is recorded throughout the process. The test may be terminated upon the occurrence of shear failure. The failure may take place around 2 to 5 minutes after the test begins. Data from FVT is first converted into FVT strength, which will be then corrected based on the soil plasticity index to produce the undrained shear strength value of the soil. Overconsolidation ratio may be determined as well.

Corrosion under Pipe Supports (CUPS) - part 7: NDT-Multiskip The Multi-Skip is used for corrosion detection of difficult to access areas of piping/ pipelines, around obstructions such as pipe supports, clamps and saddles. M-Skip is an ultrasonic shear wave ‘transmit-receive’, quantitative technique that locates probes on either side of an obstruction. Ultrasound is transmitted through the wall of the pipe, beneath the external obstruction, and is received on the far side with probe separations up to approximately 1 m. The ultrasonic waves ‘skip’ between the internal and external surfaces and the arrival times of the signals are used to calculate wall thickness. Corrosion is detected through loss of signal amplitude; reduced signal arrival times and changes to signal shape. The M-Skip scanner can reduce inspection times and associated costs by eliminating the need to lift a pipe off its support to scan the inaccessible area with accuracy of the resulting wall loss measurements can be high as +/-1 mm. Multi-Skip measurements are made with scanning ultrasonic Time of Flight Diffraction (ToFD) equipment, providing grey-level plots showing amplitude as function of scan position (x-axis) and time (y-axis). The general (average) wall thickness can be calculated from the arrival times of a series of skip signals using a least-squares fit algorithm. A local wall loss response will show up as an arc-type signal somewhere between two skip signals. Multi-Skip is better suited to sizing of isolated pits of relatively thick-walled components >10 mm thk. Multi-Skip is typically suitable for plate greater than 10 mm thick. Multi-Skip needs the surface under the probes to be relatively free from loose scale, although experience has shown Multi-Skip to be less sensitive to surface finish than CHIME. For heavily corroded components, especially those with thinner walls, the Multi-Skip signals may disappear completely due to scattering at the rough surface, resulting in loss of sizing information, although detection capability is good. Multi-Skip is also used as complementary technique to CHIME to give more quantitative sizing for indications in the range of 10% to 40%. #cups #piping #supports #corrosion #assetintegrity #management #inspection #ndt #nde #rootcause

When is your shell too thin? Shell thickness calcs per Section VIII Div 1. A common vessel in my area is the horizontal 1440 psi 54” ID portable test vessel made from 2 ¼” thick SA-516 70N material. What is the minimum required shell thickness for internal pressure by code? Let’s assume this 1440 psi vessel has a design temperature of  200°F and the joints have been fully radiographed as this is most often the situation. The shell thickness equation to use is from UG-27(c)(1) as follows: t = PR / (SE - 0.6P) The pressure is 1440 PSI. The radius is 27”. The stress value at that temp is 20,000 PSI. And the joint efficiency is 1.0 due to fully radiographed type 1 joints. Solving for t: t = (1440)(27) / ((20,000)(1.0) - (0.6)(1440) t = 38,880 / (20,000 - 864) t = 38,880 / 19,136 t = 2.03” Throw on a design corrosion allowance of 0.125” and now you see why all these vessels are built out of 2 ¼” nominal plate. What do you think? Have any spots in your shell nearing minimum thickness? Time to look at a repair, I'd say.

Very interesting topic on how these methods try to make the design more economic by introducing modifications to older theories.

Severn’s Oblique Cone Technology (OCT) Triple Offset (TOV) Butterfly Valve goes beyond meeting safety accreditation with its innovative features and engineering excellence employed in the design process, Severn is putting safety first for its customers. Within Severn’s OCT TOV Butterfly Valve is a corrosion allowance. Due to valves being susceptible to changes in working environments and process conditions the OCT TOV Butterfly Valve has been designed to be able to concede material to corrosion over time without the pressure, flow, integrity or safety of the valve being a concern. Find out how Severn has ensured safety is paramount with the design of the OCT TOV Butterfly Valve via the link below: https://lnkd.in/eSQNCsTb #Innovation #EngineeringHeritage #EngineeringExcellence #Engineering #Safety #SevereService #ButterflyValve #Valves #Research #Design #Itallflowsfromexpertise

Crack growth can be mitigated when reinforced with a high-strength composite repair system. See how below. ⬇️ As composite reinforcement testing has grown over the last few decades, their application properties have extended dramatically. Advanced FRP crack testing programs have seen composite reinforcement of various defects yield impressive results. In one testing program, the following conditions were observed: ➤ 30%-deep simulated crack-like defects (EDM notches) were installed on several pipe samples. ➤ The pipe samples were wrapped with a high-strength carbon fiber composite repair. ➤ The samples were then pressure cycled between 100-1,531 psi until failure or 25,000 cycles were achieved. ➤ Samples that reached the 25,000-cycle runout were then burst-tested until failure. The test program concluded that the presence of the composite wrap significantly increased the stiffness of the reinforced region. Despite the presence of the crack beneath the repair, all failures occurred outside the repair, confirming that the composite wrap performed as intended. #pipeline #repair #advancedfrpsystems #validation

Applying waterproofing by using compressor pressure is much better to make sure meeting required FDT thickness.

🔔 To complete the range of products, #OlmetItaly can provide also the OSM magnetic boxes: the highest quality magnet that guarantees extraordinary durability and reliability over time. 🔔 Formworks shuttering system play an essential role in the production of concrete elements. Their adaptability, reliability and longevity are the key to efficient production. The OSM magnetic system mostly consists of an external steel box, a built-in permanent magnet and an integrated push button for activation and deactivation, to ensure the best standards of adhesiveness to the casting surface and safety of use. The OSM system provides the basics for a fast and rational formwork system, to manufacture high-quality precast wall panels and other precast elements while preventive excessive tear and wear of the casting surfaces. Therefore, the OSM system is the basic device for assembling shutters or casting separators made of steel, wood and aluminium. Using different accessories, it is possible to fix any kind of small, medium or large size insert in an extremely safe way. info@olmetitaly.com

Tube surface perfection inspection