Mathematics – Logic
Scientific paper
Jan 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002iaf..confe.467d&link_type=abstract
IAF abstracts, 34th COSPAR Scientific Assembly, The Second World Space Congress, held 10-19 October, 2002 in Houston, TX, USA.,
Mathematics
Logic
Scientific paper
The performed investigations of the character of changing the leakage of control gas through flange connections in the process of drawing- up the bolts in to calculation moment and subsequent lowering of bolt loading to zero have shown the following. Gradual reduction of leakage through a gasket occurs in the process of increasing the tightening torque up to its complete absence. But there is no leakage through the unloaded gasket after untwisting all nuts and removal of fastening bolts from flanges. The performed analysis has shown that this effect is caused by cold weldability of the gasket with flanges; this is a result of flowing of its material into microrough holes of contact surfaces of flanges at plastic deformation with formation of strong and dense contact. Some technological methods of formation of undetachable joint have been developed for practical application of this effect. According to one of those methods, drawing- up the gasket is performed with the help of flanges preliminarily. Those bolts are substituted by less strong standard bolts for drawing- up by less moment after achievement of stress needed. Method of pressurization of the joint is more effective when technological detachable flanges and bolts are used for reduction of the gasket up to its plastic state. Those flanges and bolts are removed after drawing- up; after that standard flanges are loaded by the moment used for reception of effort only from pressure of operational medium in the pipe- line (Qoper.m.) because drawing- up of the gasket by effort (Qeff.) that provides its plastic state, is already achieved. Then we exclude the first component (Qeff.) in dependence which is known from technical literature: Qdraw. = Qeff . + Qoper .m. = qFgas. + PFpip. (1), and the final formula for calculation of the effort of drawing- up the joint (in which drawing- up the gasket with provision of cold weldability is carried out preliminarily before drawing- up the standard bolts) is expressed in such a way: Qdraw. =Fpip.(2), where q- specific pressure (stress) on the gasket which provides flowing holes of sealing surfaces at plastic deformation. q=(250-270)MPa for joints with closed sealing gate and a gasket made of copper; Fgas., Fpip.- areas of the gasket and the pipe- line; P- pressure value of medium in the pipe- line. Numeric values of effort of drawing- up which are calculated in accordance with dependence (2), for example, for locking joint, with internal diameter d1= 0.125 m sealed by the copper gasket (which operates under operational medium pressure P=2MPa), are 9.5 times less than those obtained in accordance with dependence (1). Necessary moment of drawing- up this joint is reduced in proportion to effort of drawing- up. The proposed technical solution changes the principle of designing the flange joints of fuel systems in which load- carrying elements ill not be available for provision of necessary drawing- up the gasket, and the designed structures will consist of thin flexible flanges and bolts, so there will be no relaxation of their stresses. If disassembly of such joints is needed, then one of the flanges contains some threaded holes along the perimeter for installation of technological bolts in those holes; those bolts press out the respective flange.
No associations
LandOfFree
Practical Usage of Effect of Cold Weldability of Metals in Joint of Plastically Deformable Gasket and Flanges of Detachable Joint of Fuel Pipe-Line does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Practical Usage of Effect of Cold Weldability of Metals in Joint of Plastically Deformable Gasket and Flanges of Detachable Joint of Fuel Pipe-Line, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Practical Usage of Effect of Cold Weldability of Metals in Joint of Plastically Deformable Gasket and Flanges of Detachable Joint of Fuel Pipe-Line will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1331765