Trends in the Development of Machinery and Associated Technology ” TMT 2008 , Istanbul , Turkey , 26-30 August , 2008 PERFORMANCE CHARACTERISTICS OF POLYURETHANE FOAM GASKETS
In this study, the performance characteristics of polyurethane foam gaskets have been investigated experimentally in a flanged joint system. Accordingly, it is possible to be compared the test results of polyurethane foam gaskets which have different properties by using this designed testing apparatus. Samples are prepared as foam in place method by using polyurethane material. Whilst samples have been prepared, mixing ratio of 2 different materials, weight in grams value of foamed gasket in 1 second (g/s) and temperature of foamed surface are taken variable parameters; ambient temperature, same type material and polyurethane foam gasket machine foaming velocity are taken constant parameters. The results obtained from the experiment are targeted to use by selecting the optimum gasket according the operating conditions.
A New Concept of Static Rubber Gasket for Sealing Rough Surface
This paper reports on a new concept for static seal designs taking into consideration the surface roughness of sealing surfaces. The concept focuses on fluid penetration from the interstices between the seal and counterface caused by surface roughness. In the study, we investigated the relation between the leakage and surface roughness of the sealing surface of the elastomer seal. At the same time, we also analyzed the contact state of the elastomer seal based on the equations of Ishiwata et al. on deformation of elastomer surface into rough surfaces [1]. The micro-leakage testing machine (SMLA) developed by the authors was used to measure micro-leakage at high precision and in a short time [2]. The results showed that the sealing phenomena were related to the ratio of seal surface contact pressure P s / elastic modulus of seal E, determined by the compression ratio of seals, and does not depend on the chemical structure and hardness of the elastomer used. Furthermore, we reviewed the equations for predicting leakage based on the shape and elastic modulus of the elastomer seal, surface roughness of the seals and counterfaces, and using conditions, and found that these can be simulated.
Badush Dam, NW Iraq : A Geological Study
The river Tigris flows from Turkey towards Iraq in its northwestern part dissecting the whole Iraqi territory. During 1981– 1986 a very large earth fill dam was constructed, which is Mosul Dam impounding the flow of the Tigris River. It is the largest dam in Iraq and one of the largest in the Middle East. The geological conditions of the dam site and surroundings, however, are not suitable due to thick exposures of the Fatha Formation, which consists of marl, clay, limestone and gypsum. The gypsum and limestone beds are highly karstified causing severe problems to the dam foundation. Mosul dam suffers from serious problems due to the presence of karstified rocks; therefore, the Ministry of Irrigation in Baghdad, decided to construct a protection dam downstream of Mosul Dam; it is called Badush Dam. The geological conditions at Badush Dam site are the same as those at Mosul Dam site, which means the foundations of the dam are located on karstified rocks. Therefore, grouting works were planned and designed and it was partly performed from the beginning of the construction in 1988. The construction of the dam; however, stopped in 1991 due to the consequences of the First Gulf War. The constructed parts of the dam are (30 – 40) %. In this study, we have presented the main problems, which will cause real danger to Badush Dam, if its construction is re-started, and we have suggested many requirements to avoid any hazard that may cause the collapse of Badush Dam.