Features of calculating kinematic and roughness parameters at abrasive finishing of shut-off surfaces of gate valve bodies connecting pipes

Introduction. The author defines main provisions for peculiarities of the kinematics of plant lapping in the process of finishing shut-off elements of the valves, as well as methods for determination of operating parameters and values of roughness in the process of abrasive finishing of sealing surfaces of valves. Materials and Methods. The kinematic scheme of grinding machines was developed to determine the angular velocity of rotation of an instrumental disc and lapping machine. Based on the developed kinematic scheme, we obtained analytical expressions to determine the capacity of the machine's drive motor and cutting elements, as well as the angular and linear speeds of rotation of tool drive and laps. There were also developed trajectory traces of grid points of the lapping tool at its movement along with the treated surface details of pipe fittings. Results. There are given examples of calculation of kinematic parameters and roughness of the treated sealing surface of gate valves with the diameter DN = 100 according to established analytical dependencies for rough and finish lapping. The coordinates of the moving tools were calculated with visualization of trajectory points using special software Lazarus. The coordinates were calculated and the trace of the moving point tool was built. The specific space which characterizes the capacity of the sealing surfaces was calculated. Discussion and Conclusion. Calculations allowed us to determine how to place the lapping tool relative to the machine's sealing surface for optimization of the treatment process. Preliminary calculations showed that the area of lapping tool's contact with the workpiece and the optimum angle of contact would change slightly within the relative probability of error of 5% and 10%.