The fatigue life of welding structures includes technological life and service life.

During the drilling operation of directional wells and horizontal wells, there are many factors that may obviously influence working life of screw drill, which include the usepattern of screw drill, the control of drilling fluid performance, the optimization drilling parameters and operational method, etc.

Coiled tubing(CT) working life is very short,which is main fact to affect cost of CT services.

Based on the problem of corrugated roller working life, the study of the behavior for corrugated roller 50CrMo steel and its cyclic heat treatment process was carried out, and the hardness and microstructure of the roller were analyzed.

Then the service life of the petroleum pipeline containing the crack is predicted in this paper.

This paper analyses the factors influencing the service life of spiral bevel gears on rigs and proposes some measures to improve them.

Concrete durability is being quantified,and becoming part of reliability and service life design of reinforced concrete structures.

Pile foundation of the main tower of palms-together dagoba in Famen Temple was designed for 100 years project service life.

By dissecting the earlier having metal-shell quartz pressure sensor of operating life of oscillations,operating life mechanism of the sensor is analyzed and discussed.