Search
Filters
Close

98040 RECORDING OF LOCAL FLOW DISTURBANCES BEHIND OBSTACLES WHERE MESA ATTACK HAVE OCCURRED

Product Number: 51300-98040-SG
ISBN: 98040 1998 CP
Author: Gisle Onsrud, Terje Sontvedt
$0.00
$20.00
$20.00
Laboratory investigations have demonstrated that flow induced limits fortheapplication of C-steel exist. Flow limits have been found for all types of C-steels investigated. Obstacles in pipes constitute exposed areas for destruction of the carbonate film and determine the maximum allowable production rate rather than the smooth pipe sections. The purpose with our ongoing research project istoconnect the strength of carbonate films with stress caused by fluid flow. Flow-induced wall shear stress fluctuations on smooth pipe sections and behind obstacles have been systematically mapped. Mean wall shear stress and shear stress amplitudes have been recorded downstream obstacles in a 69 mm diameter stainless steel pipe with single phase oil flow. The influence from obstacle location, its height and flow velocity on mean shear stress, shear stress amplitudes and dominant frequencies have been studied. The fast K-tubes allowed recording of the instantaneous shear also when the stress cycled to negative values. Relationships for the wall shear stress amplitudes, frequencies and mean values have been developed. The paper shows why weld like obstacles constitute exposed areas, A model has been developed which describes the time to failure of the corrosion product when delaminated from the base metal. This model connects the residual strength of the corrosion product with the fluctuating wall shear from the liquid, its dominant frequency and the mean shear. The model allows transformation of observed flow limits in the laboratory to completely different flow conditions. Simple limits to production rate in the form of wall shear have been found for smooth pipes and pipes with weld like obstacles. Keywords: corrosion, mesa attack, wall shear stress
Laboratory investigations have demonstrated that flow induced limits fortheapplication of C-steel exist. Flow limits have been found for all types of C-steels investigated. Obstacles in pipes constitute exposed areas for destruction of the carbonate film and determine the maximum allowable production rate rather than the smooth pipe sections. The purpose with our ongoing research project istoconnect the strength of carbonate films with stress caused by fluid flow. Flow-induced wall shear stress fluctuations on smooth pipe sections and behind obstacles have been systematically mapped. Mean wall shear stress and shear stress amplitudes have been recorded downstream obstacles in a 69 mm diameter stainless steel pipe with single phase oil flow. The influence from obstacle location, its height and flow velocity on mean shear stress, shear stress amplitudes and dominant frequencies have been studied. The fast K-tubes allowed recording of the instantaneous shear also when the stress cycled to negative values. Relationships for the wall shear stress amplitudes, frequencies and mean values have been developed. The paper shows why weld like obstacles constitute exposed areas, A model has been developed which describes the time to failure of the corrosion product when delaminated from the base metal. This model connects the residual strength of the corrosion product with the fluctuating wall shear from the liquid, its dominant frequency and the mean shear. The model allows transformation of observed flow limits in the laboratory to completely different flow conditions. Simple limits to production rate in the form of wall shear have been found for smooth pipes and pipes with weld like obstacles. Keywords: corrosion, mesa attack, wall shear stress
PRICE BREAKS - The more you buy, the more you save
Quantity
1+
5+
Price
$20.00
$20.00
Product tags
Also Purchased
Picture for 98048 INITIATION AND GROWTH OF MESA
Available for download

98048 INITIATION AND GROWTH OF MESA CORROSION ATTACK DURING CO2 CORROSION OF CARBON STEEL

Product Number: 51300-98048-SG
ISBN: 98048 1998 CP
Author: Rolf Nyborg
$20.00
Picture for 98029 MESA CORROSION AlTACK IN CARBON
Available for download

98029 MESA CORROSION AlTACK IN CARBON STEEL AND 0.5 % CHROMIUM STEEL

Product Number: 51300-98029-SG
ISBN: 98029 1998 CP
Author: Rolf Nyborg, Arne Dugstad
$20.00
Picture for 99042 CO2 CORROSION MODEL FOR CARBON STEEL
Available for download

99042 CO2 CORROSION MODEL FOR CARBON STEEL INCLUDING A WALL SHEAR STRESS MODEL FOR MULTIPHASE FLOW AND LIMITS FOR PRODUCTION RATE TO AVOID MESA ATTACK.

Product Number: 51300-99042-SG
ISBN: 99042 1999 CP
Author: Anne Marie K. Halvorsen, Terje Santvedt
$20.00