Tube Skin Thermocouple How to measure the correct Tube skin temperature in a Heater.

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  • Tube Skin Thermocouple How to measure the correct Tube skin temperature in a Heater
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  • The Fan Tip thermocouple Drawing of the junction
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  • Fan Tip Specifications Calibration: Type K or N Sheath Material: Hastelloy X Diameter: 6.0 or 8.0 mm Accuracy: +4C
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  • The most common used thermocouples Fan Tip Pad Style Knife-edge
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  • Comperison of accuracy Surface measurements are always trublesom and usually inaccurate. There are many methodes used for measuring tube surface temperatures. This is usually a difficult measurement becouse of the temperature of the air or flame around the tube is higher than th tube itself, leading to a positive error The Fan Aproache is both more accurate and has a faster response then other designs. Using Hastelloy X material this also give long life A test has been carried out compering the thre different types In this test the real tube temperature was 500C and the ambient gas temperature was 800C resulting in the following data: SyleIndicated temperatur CError C% Knife-edge521 21 4.35 Pad Style520.9 20.9 4.0 Fan Tip504.5 4.5 0.7
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  • Hastelloy X material PRINCIPAL FEATURES Strength and Oxidation Resistance HASTELLOY X alloy is a nickel- chromium-iron-molybdenum alloy that possesses an exceptional combination of oxidation resistance, fabricability and high-temperature strength. It has also been found to be exceptionally resistant to stress-corrosion cracking in petrochemical applications. X alloy exhibits good ductility after prolonged exposure at temperatures of 1200, 1400, 1600F (650, 760 and 870C) for 16,000 hours. Haynes International Inc X alloy Easily Fabricated HASTELLOY X alloy has excellent forming and welding characteristics. It can be forged and, because of its good ductility, can be cold worked. X alloy can be welded by both manual and automatic methods including shielded metal arc (covered electrodes), gas tungsten arc (GTAW) and gas metal arc (GMAW). The alloy can also be resistance welded. Haynes International Inc X alloy ASME Boiler and Pressure Vessel Code HASTELLOY X alloy plate, sheet, strip, bar, tubing and pipe are covered by ASME specifications SB-435, SB-572, SB-619, SB-622 and SB-626 under UNS Number N06002. Haynes International Inc X alloy Heat-Treatment Wrought forms of HASTELLOY X alloy are furnished in the solution heat-treated condition unless otherwise specified. X alloy is solution heat- treated at 2150F (1177C) and rapid cooled. Bright annealed products are cooled in hydrogen. Haynes International Inc X alloy Available in Convenient Forms HASTELLOY X alloy is available in the form of plate, sheet, strip, billet, bar, wire, covered electrodes, pipe and tubing. Haynes International Inc X alloy Useful for Aircraft, Furnace and Chemical Process Components X alloy has wide use in gas turbine engines for combustion zone components such as transition ducts, combustor cans, spray bars and flame holders as well as in afterburners, tailpipes and cabin heaters. It is recommended for use in industrial furnace applications because it has unusual resistant to oxidizing, reducing and neutral atmospheres. Furnace rolls of this alloy were still in good condition after operating for 8,700 hours at 2150F (1177C). HASTELLOY X alloy is also used in the chemical process industry for retorts, muffles, catalyst support grids, furnace baffles, tubing for pyrolysis operations and flash drier components. Haynes International Inc X alloy Specifications For information on specifications to which this alloy can be ordered, please contact one of the locations shown on the Haynes Home Page and ask for bulletin H-1034 Applicable Specifications.Haynes Home PageH-1034 Applicable Specifications
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  • Installation of the Fan Tip This drawing shows a typical general installation with expasion coil
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  • ARI Installation drawing
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  • Fan Tip installation ExXon
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  • Installation Statoil
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  • ATEX Installation
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  • Mounting methodes Welding Welding has been the traditional method for this application Metal spraying At Statoil Mongstad a method of metal spraying was developed around 1986
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  • Welding Time consuming Tube has to be preheated The weld must be annealed Risk for cracks in the tube X-Ray is sometimes a demanded If performed properly it is a god solution
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  • Metal Spraying Very time efficient installation No damage or physical change in tube material Tube temperature only 100 C during installation No heat treatment
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  • Procedure for metal spraying Cleaning the tube by blasting Fixing the Fan Tip to the tube First layer of metal Second layer of metal Outside layer of Alumina Oxide
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  • Cleaning the tube
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  • Fixing the Fan Tip to the tube
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  • First layer of metal
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  • Second layer of metal
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  • Outside layer of Aluminium Oxide
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  • Arc spray machine
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  • References in Nordic Countries Statoil Mongstadmetal spray Statoil Kalenborg Preem Raff Gothenburgmetal spray Preem Raff Lysekil ExXon Tnsberg Borealis Stenungsundmetal spray


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