METHOD OF PREVENTION OF BREAK OF GAS LINES Russian patent published in 1999 - IPC

FIELD: pipe transport; erection of new pipe lines and reconstruction of existing technological pipe lines of compressor and pump station piping systems. SUBSTANCE: indication of surface hardness is entered in Quality certificate of pipes and the following marks are made on surface of pipes: green marks where surface hardness exceeds 105 to 110%; yellow mark where it exceeds 110-125% and red marks where it exceeds 125% relative to undistorted material. Then, stressed deformed state is calculated taking into account construction of pipe having unequal strength and probability of break of pipe (mean-time-between-failures) ≪P_H≪ is calculated. Prior to mounting lengths of pipes in trench, they are subjected to bending test in elastic zone and acoustic emission signals are recorded in tension and compression zones; tension and compression stresses are created in segments through turn around axis. Recorded acoustic emission signals are marked with "+" in tension zone and with "-" in compression zone. Check of state of piping systems in the course of operation is effected by means of bench marks, force meters of dampening devices, probes for measuring corrosion characteristics of soils and acoustic emission sensors. Parameters thus measured are furnished to software units by means of telemechanics where present magnitude of probable break of piping system (means-time-between-failures) ≪P_t≪ is automatically calculated and when P_t≥P_H, units of compressor stations are automatically disconnected and protective cocks are shut off. EFFECT: enhanced reliability of pipe lines. 2 cl, 3 dwg