Comment prédire les tapures de trempe ou les maladies agricoles ? Comment inspecter les fuselages en composite ? Quels sont les nouveaux produits et procédés en assemblage, en traitement de surfaces, en robotisation ? Quelles sont les grandes tendances de la simulation numérique ? Les réponses sont dans ce nouveau « Best of » veille du Cetim à déguster … sans modération.
Control valve (actuator) is the frequently moving terminal Instrument of the control system. To avoid the leaking of the actuator, there is packing at the moving parts. However, the friction caused by the packing can do harm to the control of the system. The washing effect of the media, high temperature, high pressure, frequent movement and other effects can result in the leaking of the packing and the deformation of the valve stem, which causes the change of the friction. In this paper, published in Sensors & Transducers, Vol. 177, Issue 8, August 2014, it’s theoretically analyzed the relationship of the friction of the packing and the static performance of the control valve, and offered a method to check the quality of the moving parts by attaching a strain gage (strain rosette) to the empty part of the valve stem. This method has been demonstrated via experiment and a method to do error detection is provided at last. Paper published by http://www.sensorsportal.com/.
A paper published on the site of FM Global. The purpose of this technical report is to explain corrosion in fire protection systems (FPS). Factors such as pipe weld corrosion, residual water in dry pipe systems, trapped air in wet pipe systems, microbiologically influenced corrosion, and corrosive water chemistry are discussed. A corrosion resistant sprinkler system for highly corrosive exhaust duct is also addressed. This report provides the basis for development of corrosion mitigation strategies of existing FPS and lays out directions for further study on corrosion mitigation and management of FPS.
This paper is published on http://www.boltcouncil.org by Salim Brahimi, President at IBECA Technologies Corp, Chairman, Committee F16 (Fasteners) at ASTM International, The objective of this paper is to distil the latest knowledge related to hydrogen embrittlement into know-how in a manner that is complete yet simple, and directly applicable to fasteners. The topic is divided into basic components. First is a description of the theory and mechanism of hydrogen damage, followed by a discussion of conditions that are necessary for hydrogen embrittlement failure to occur. The fundamentals are followed by a description of HE test methods, guidelines for processing, surface cleaning, coating (particularly electroplating), and baking.
