Based on the partial modeling result of tailrace surge tank,a study on the hydraulic characteristics of the throttled surge tanks with the linking pipe is made by table-lookup calculation and experience formula calculation in respect of water flaw direction in the linking pipe and the effect of pipe diameter and flow ration on the head loss coefficient of the surge tank.

Analyzes the effect of linking pipe velocity head and the momentum exchange between flow to and from the surge tank and that in the draft tunnel on the stable sectional area of the downstream surge tank with linking pipe by using the head loss coefficient obtained from Gardel s empirical equations for T-junction flow.

Based on the results of experimental data of the tailrace surge tank of Yi Xing pumped-storage Station in Jiangsu province, this research investigates the methods for the head loss coefficients of throttled surge tank with linking pipe by means of the me.

In pressure design of reinforcement calculation of process piping branch connection,the use of pressure area method is the same as that of area replacement method in essence,the difference of which only exists in the different reinforcement scopes.

It is a new type of low-cost-automation welding system for pipe-connection.

A new type of automatic arc welding machine for pipe-connection of bicycle frames was designed and its structure and working principle are described in this paper .