Оценка степени герметичности шаровых кранов DN800, установленных на компрессорной станции «Портовая»

Abstract

Leak integrity guaranteeing is the main requirement to shut-off valves. Possibilities to prolong an operation life as well as real activities on leaktightness restoration depend on leakage value at valve’s closing element. The leakage value can be efficiently and quantitatively evaluated by recording acoustic signals. The levels of acoustic signals are different at different testing conditions. In order to determine the correspondence between different levels of acoustic signals and different leakage values, it is necessary to carry out some experiments on real tested objects. Since 2011 “Lenorgenergogaz” together with “INTERYUNIS” have been devising a technique for leak integrity evaluation of shut-off valves at gas-compressor stations. A large amount of experiments on more than 130 units of shut-off valves installed both on ground and underground was carried out. The algorithm for leakage detection in case a typical “leakage” signal is received has been developed; empirical dependences for leakage evaluation on the basis of acoustic emission signal parameters have been obtained for main types of shut-off valves installed at “Gasprom Transgas St. Petersburg” objects. The article presents the results of research work on leak integrity evaluation of valves at “Portovaya” gas-compressor station. The stabbing valves DN800 mm installed at a segment of a reverse pipeline were the object of the research. Leak integrity test was carried out using both a manometric and an acoustic technique with quantitative leakage evaluation for every closing element. The results of each method have agreed with an error no more than 20%. Visual inspection of stabbing valves inner parts has shown that seat guide firming are damaged; this fact indirectly confirms the quantitative evaluation of shut-off valves leaktightness. Conclusions made on the basis of obtained results can serve as a foundation for acoustic emission leak integrity evaluation technique for shut-off valves.