ASSESSMENT OF VALVING SYSTEM DESIGN RISK UNDER CONDITIONS OF EXTREME OPERATION

A working order of a pipe fitting is a significant aspect in a trouble-free operation of technological objects in oil and gas production. It particularly concerns a safety valve protecting equipment against overpressure. In the field of high pressure, costs and temperatures the installation of pulse-safety devices is preferable. But, the complexity of their design and a substantial impact of a pulse valve sensitive element upon the whole correct work of a safety system in extreme conditions of operation increase design risks. With the purpose of their decrease there are considered possible circuits of the sensitive element standby in a pulse valve. By means of the method of reliability prediction on statistical models there are analyzed dependences of sensitive element failure probabilities as a spring and metal bellows in extreme conditions of operation. The conclusions on the application of a structural standby with a non-loaded reserve under definite conditions of operation and an optimum choice of structural materials for layers in multi-layer metal bellows are drawn.