The build up of dye was determined.

Analysis on the lifting force of the tower lifted almost vertically;

In the field tests, it has been proved that the safety of oil tank lifting is closely correlative with the lifting force and the stress status at the action point.

For better using the double seats valve,the characteristics of the valve such as the flow passage capability,the pressure loss,the lifting force and the working stability were test investigated in the present paper.

Experiment Study on Lifting Velocity and Concentration of Coarse Particles for Vertical Hydraulic Lifting;

The critical lifting silt velocity for vertical hydraulic lifting is investigated by experiments,and the partly theoretical and partly experienced formula on the critical lifting silt velocity calculation for vertical hydraulic lifting is derived.

On the basis of previous researches,the concentration characteristics of large size particles in vertical pipes by hydraulic lifting were studied through experiments and theoretical analyses.

Based on the characteristics of solid liquid flows such as their density, concentration, elastic modulus and resistance, the unsteady coarse grained solid liquid flow in hydraulic hoisting is simulated.

Based on the slurry pipeline transportation theory, the paper studies the pressure-loss form of manganese nodule liquid-solid two-phase flow in the hydraulic lifting pipe, and meanwhile deduces the model of pressure loss and its calculated formulas, which provides theoretical basis for the dynamic design of hydraulic hoisting.