...Basil A. Housari; Ali A. Alkelani; Sayed A. Nassar An improved mathematical model is proposed for predicting clamp load loss due gasket creep relaxation in bolted joints, taking into consideration gasket behavior, bolt stiffness, and joint stiffness. The gasket creep relaxation behavior...

... behavior of pipe flange connections at elevated temperature, by incorporating the stress–strain curves of sheet gaskets measured in the temperature range which covers its usual service condition. Then, the reduction rate of bolt preloads at elevated temperature is systematically evaluated. The analytical...

...Z. G. Sun; B. Q. Gu The leakage rates of bolted flanged connections change with service time due to the gasket contact stress relaxation and degradation of gasket material. The nonuniform distribution of gasket contact stress has significant influence on the leakage behavior of the connections...

...Lotfi Grine; Abdel-Hakim Bouzid In recent years, quite few experimental and theoretical studies have been conducted to predict gas leak rate through gaskets. However, a very limited work is done on liquid leak rates through gaskets. The slip flow model is used to predict liquid flow through porous...

... the operator to a potential risk because the bolt load alteration can produce a gasket load unbalance, which results in the local gasket contact stress to drop below some critical value, causing major leak and hence jeopardizing the life of the worker. This paper addresses the issue of the contact stress level...

...Lotfi Grine; Abdel-Hakim Bouzid The present work deals with the theoretical and experimental studies of gaseous flow through tight gaskets. The paper presents an innovative approach to accurately predict and correlate leak rates of several gases through nanoporous gaskets. The new approach is based...

...Abdel-Hakim Bouzid; Hichem Galai The poor leakage performance of flanges with full face gaskets is attributed to the low reliability of the existing design methods, and in particular, their lack of assessing accurately the bolt and gasket load changes. The prediction of tightness of bolted joints...

...Toshiyuki Sawa; Ryo Kurosawa; Wataru Maezaki The contact gasket stress distributions in a rectangular box-shape bolted flange connection with a compressed sheet gasket subjected to internal pressure were analyzed using the finite element method. Leakage tests were also conducted for an actual...

...Sayed A. Nassar; Xianjie Yang Novel formulation was proposed for studying bolt elastic interaction during the tightening of a group of fasteners in flat faced gasketed joints. The model was used for developing tightening strategies that would achieve a more uniform clamp load in the flange...

... for modern flange design. The substitution of the external applied moment by an equivalent pressure is excessively conservative and not realistic since it assumes that the achieved tightness is that of a gasket unloaded entirely to a minimum stress whereas in reality only a small section of it is, the rest...

... is often estimated from the creep of the gasket and the bolts. The creep behavior of the flange ring, the hub, and the cylinder is often neglected. Apart from an acknowledgement of relaxation due to the creep, the designer has no specific tools to accurately assess this effect on the bolt load relaxation...

...Ali A. Alkelani; Basil A. Housari; Sayed A. Nassar A mathematical model is proposed for predicting the residual clamp load during creep and∕or relaxation in gasketed joints. An experimental procedure is developed to verify the proposed model for predicting the gasket relaxation under a constant...

...William J. Koves This paper uses an analytical model based on the Pressure Vessel Research Council (PVRC) ROTT test gasket constants to compute leakage in gasketed flange joints subjected to internal pressure and external bending moments. The model results are compared to test data, and design...

.... The characteristics of the connections with the different nominal diameters from 2 in . to 20 in . such as the contact gasket stress distribution, the hub stress, and the load factors were examined. The results from the finite element analyses were fairly consistent with the experimental results concerning...

...Sayed A. Nassar; Ali A. Alkelani An experimental study is presented in order to determine the clamp load loss due to elastic interaction and gasket creep relaxation in bolted joints. Studied parameters include the gasket material and thickness, bolt spacing, tightening sequence, fastener grip...

... as a powerful tool for elevated temperature flange designs. This paper addresses the effect of the internal fluid operating temperature on the variation of the bolt load and consequently on the gasket stress in bolted joints. The theoretical analysis used to predict the gasket load variation as a result...