Taking the example of water supplying project in east Xiamen,it compares and analyses stressed water pipe synthetically by qualitative and quantitative ways from aspects such as economic diameter,limited capacity technical features and comprehensive cost.

In view of the problems existing in gravity conduit design,this paper takes the minimum cost of the gravity conduits as objective function,presents a new optimization design method for gravity conduits by using dynamic programming,and discusses the equivalent diameter,flow distribution,link pipe installation and reliability calculation of the gravity conduits.

Author points out hazards and serious consequence of ship transportation, and discusses the physical factors for eliminate hazards of pipeline transportation.

It presents operation safety of oil and gas pipeline in China,especially many problem caused by man-made destroy,summarizes main factor of affecting oil and gas pipeline transportation safety and highlights to put forward to a few measures of ensuring pipeline operation safety management.

From the point of energy exchange in open system and the continuity principle of the network Graph theory, using the integral technique of modeling and simulating, we have researched the problems of leak detecting and precise location in pipeline transportation.