Based on the Moody model and complied with the modular modeling ideology and principle,a general break simulation model has been proposed for both single and two phase conditions in a thermal liquid pipe.

By using Harmilton's principle and Euler's theory of elastic beam and taking Coriolis force of fluid into consideration,this paper builds the mathematical model for the problem on free vibration of elastic pipe conveying fluid,employs the Galerkin approach to find solutions to the model,analyzes the solutions and obtains corre.

The general expression for the instantaneous potential energy functional of elastic system is given at first, and then the special for the arbitrarily curved and twisted pipe conveying fluid is obtained.

This paper discusses acid rinsing maintenance of hydraulic pipes in hoisting and conveying machinery,including basic procedures and acid liquid compounding.