This paper introduces the uses and working principles of TBW250/ 40 mud pump in geological exploration drilling, and in the light of the problems o f the valve base occurring in its application, puts forward a restoring method o f increasing the aperture and then making the inserted cover.

In-situ turning repair technique for safety valve seats in power plants;

Development of valve seat for CNG engines and the valve test for matching;

Cause for damage to pre-start valve seat of CB25-91/10/1.2 steam turbine regulator valve;

Analysis and repair of crack on intercept valve base oflarge imported steam turbine;

The processing technology for the valve base is introduced and the forging process is analyzed.

The results show that,as the emulsion enters into the lubricating oil,gap corrosion will be generated on the surface of the valve base,which makes the mating surface peeled off and the gap increased.

Machining methods for thin walled support ring seat;

The text introduces the structure features,characteristic parameters and workingprinciple of a new type of Inlet Ball Valves for Water Turbo,discussing and analysing ahydraulic relay to open the ball valve and a weightily hammer to close the ball valve,andthe structure of a single eccentric valve seat that can balance the pressure difference betweenthe inlet and outlet of the ball valve.

Progressive die design of the elastic seat of hard seal butterfly valve;

The effect of WC powder additive amount on the hardness, density and bending strength of the high Cr Nb Mo sintered valve seat insert material produced by adding WC powder, the material hardness after quenching and tempering as well as the microstructure observation on the material by SEM were investigated.