Failure Avoidance Brief: Estimating Heater Tube Life

2008 ◽  
Vol 9 (1) ◽  
pp. 5-7 ◽  
Author(s):  
Daniel J. Benac
Keyword(s):  
Failure Avoidance ◽  
Tube Life ◽  
Heater Tube

Design and Life Prediction of Fired Heater Tubes in the Creep Range

1988 ◽  
Vol 110 (3) ◽  
pp. 322-328 ◽  
Author(s):  
R. Seshadri
Keyword(s):  
Life Prediction ◽  
Operating Experience ◽  
Creep Damage ◽  
Economical Design ◽  
Inspection Strategy ◽  
The Mean ◽  
Life Predictions ◽  
Tube Life ◽  
Creep Deformations ◽  
Heater Tube

Realistic fired heater tube-life predictions are essential to safe and economical design, proactive inspection strategy and meaningful tube retirement evaluations. The traditional method of heater tube design (API RP 530), that is based on the “mean-diameter equation,” sometimes implies tube-life in excess of actual operating experience. The main reason for this discrepancy is the interaction of cyclic radial thermal gradient, that exists across the tube wall, with the pressure-induced stresses resulting in enhanced creep damage. Upper-bound estimates for creep deformations and creep damage are obtained in this paper using a simple analytical procedure. Some broad guidelines relating to the assessment of remaining tube-life, tube retirement and inspection frequencies are presented.

Manufacturing and Testing of Welded Stainless Steel Tubing: You Have a Choice Part 2—Feedwater Heater Tubing

2008 ◽  
Author(s):  
Daniel S. Janikowski ◽  
Edward R. Blessman
Keyword(s):  
Stainless Steel ◽  
High Reliability ◽  
Cost Effective ◽  
Advantages And Disadvantages ◽  
Steel Tubing ◽  
Minimum Requirements ◽  
Manufacturing Techniques ◽  
Tube Life ◽  
Heater Tube

The stainless steel feedwater heater specifications, ASTM A688/ASME SA 688 and ASTM A803/SA 803, were developed over 30 years ago. At that time, no one envisioned the temperatures and pressures that today’s super and ultra-critical units would operate. The increased pressures, temperatures, and expectations for reliability require special manufacturing techniques and testing for long tube life. The current ASTM/ASME specifications should be considered minimum requirements, and for long term reliability a number of additional special manufacturing processes and tests are essential. This paper summarizes many of the manufacturing and testing choices that should be specified to ensure high reliability. It identifies the advantages and disadvantages of each option and provides suggestions on what should be specified to ensure a reliable cost-effective feedwater heater tube for today’s applications.

Fullerene-like Nanoparticles of WS2 as a Promising Protection from Erosive Wear of Gun Bore Nozzles

2020 ◽  
Vol 16 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Narimane Rezgui ◽  
Danica Simić ◽  
Choayb Boulahbal ◽  
Dejan Micković
Keyword(s):  
Mass Loss ◽  
Solid Lubricant ◽  
Erosive Wear ◽  
Mechanical Resistance ◽  
Protective Function ◽  
Protective Layers ◽  
Total Mass Loss ◽  
Mass Losses ◽  
Before And After ◽  
Tube Life

Background: Erosive wear causes increase in the bore diameter of firearms barrels and nozzles. Most responsible factors for this erosion are friction and heat generated during the shot. Protection from erosive wear is very important for gun tube life cycle, and various protection methods are used: adding phlegmatizers in gunpowder composition or applying protective layers on the gun bore inner surface. Objective: In this research, a possibility is examined to protect the surface of a nozzle exposed to gunpowder erosion applying a layer of tungsten disulfide fullerene-like nanoparticles, IF-WS2, known as outstanding solid lubricant of a great mechanical resistance. Methods: Nanoparticles on the nozzle surface before and after the gunfire tests were observed using scanning electron microscopy/energy dispersive X-ray spectroscopy. Gunfire tests were performed on designed erosion device. Temperatures in the defined position near the affected surface were measured with thermocouples and compared for the nozzles with and without nanoprotection, as well as the nozzle mass loss after each round. Results: For the sample with IF-WS2 lower temperatures after firing and lower mass losses were observed. Mass loss after first round was 25.6% lower for the sample with protective nanoparticles layer, and the total mass loss was about 5% lower after five rounds. After the first round the nozzle without IF-WS2 was heated up to a temperature which was for 150.8°C higher than the nozzle with IF-WS2. Conclusion: Protective function of IF-WS2 is the most pronounced for the first round. The observed results encourage its further application in firearms gun bores protection.

Failure analysis of electric-heater tube for heat-storage tank

2018 ◽  
Vol 87 ◽  
pp. 69-79 ◽  
Author(s):  
Sol-Ji Song ◽  
Sangwon Cho ◽  
Woo-Cheol Kim ◽  
Jung-Gu Kim
Keyword(s):  
Failure Analysis ◽  
Storage Tank ◽  
Heat Storage ◽  
Electric Heater ◽  
Heater Tube

scholarly journals CONTINUOUS PRODUCTION OF PURE SQUALENE BY USING COLUMN CHROMATOGRAPHY

2010 ◽  
Vol 5 (3) ◽  
pp. 251-254 ◽  
Author(s):  
Dosis Undjung
Keyword(s):  
Silica Gel ◽  
Column Chromatography ◽  
Sea Water ◽  
Solid Phase ◽  
Continuous Production ◽  
Continuous System ◽  
Raw Material ◽  
Central Kalimantan ◽  
Shark Liver Oil ◽  
Heater Tube

The purpose of this research was to produce pure Squalene using the Chromatography Column of Continuous System, so that it will be applicable in home industry. The raw material was a Shark caught from the sea water in Katingan Regency, Central Kalimantan. The result of this research concludes that the Column Chromatography of Continuous System in the experiment was able to produce pure Squalene with the level of purification of 79.89 % out of raw material was as long 180 minutes, by the elution speed of 4 mL per minute, and the eluen (liquid of the raw material) needed was as much as 900 mL, the solution lost (2 % of dietil eter in benzene) during the process was 2.04 %, the temperature in the heater tube was 110 oC, the number of the Silica gel G 40 types as what so-called solid phase in this process to purify 90 g of raw material was 90 g, and the amount of the solution remained in the pure Squalene was 1.5 ppm. Column Chromatography of Continuous System may be applicable in home industry to produce pure Squalene from Shark Liver Oil, the materials and equipment for this activity can be easily found as they are available in markets. A further analysis is needed to find out of contained compound for its further use.   Keywords: pure squalene, continuous system, column chromatography

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